Frick RDC Remote Distributed Condensing Units Installation Operation and Maintenance Guide

Brand: Frick

Model: RDC Remote Distributed Condensing Units

Type: Installation Operation and Maintenance Guide

This manual contains rigging, assembly, start-up, and maintenance

instructions. Read thoroughly before beginning installation. Failure

to follow these instructions may result in personal injury or death,

damage to the unit, or improper operation.

Remote Distributed Condensing Units

A Component of the Low Charge Central System

RDC

Check www.FrickCold.com for the latest version of this publication.

Form 170.200-IOM (FEB 2023)

Installation–Operation–Maintenance

File: Service Manual–Section 020

Replaces: None

Distribution: 3, 3a, 3b, 3c

170.200-IOM (FEB 23)

Page 2

Remote Distributed Condensing Units (RDC)

Installation - Operation - Maintenance

Indicates an imminently hazardous situation which, if not avoided, will result in death or serious

injury.

Indicates a potentially hazardous situation or practice which, if not avoided, will result in death or

serious injury.

Safety precaution denitions

Indicates a potentially hazardous situation or practice which, if not avoided, will result in damage

to equipment and/or minor injury.

Indicates an operating procedure or practice, for example, or a portion thereof which is essential

to highlight.

Warning

Caution

Danger

Notice

Contents

General Information

Preface ..............................................................................3

Job inspection ................................................................... 3

Transit damage claims .......................................................3

RDC unit identication ...................................................... 3

RDC units .......................................................................... 4

Condenser system ............................................................. 4

Liquid storage vessel ......................................................... 5

RDC control panel .............................................................5

Defrost operation .............................................................. 5

Cold weather operation..................................................... 6

Refrigerant expansion valve .............................................. 6

Pressure regulators ........................................................... 9

High pressure regulating system .......................................9

Mechanical oat valve .................................................. 9

Liquid refrigerant subcooler ............................................ 10

Liquid level probe ...........................................................10

Float switch .....................................................................10

Installation

Handling and moving .......................................................11

Relief valves and piping ................................................... 11

Installing the refrigerant expansion valves ......................11

Insulating ......................................................................... 11

Holding charge and storage ............................................ 12

Power supply and electrical wiring .................................. 12

Electrical grounding.........................................................12

VFD applications ......................................................... 13

Operation

Pre-start checklist ........................................................... 19

Pressure testing .......................................................... 19

Evacuation ..................................................................19

Pre-commissioning: Pre-initial start-up .....................19

Charging with refrigerant and initial start-up .............20

Normal start-up ..............................................................21

Normal controlled stop....................................................21

Long-term stop ............................................................... 21

Maintenance

RDC maintenance ............................................................ 23

Quarterly maintenance ............................................... 23

Semi-annual maintenance .......................................... 23

Annual maintenance ................................................... 23

Other .......................................................................... 23

Purging the system .........................................................23

Liquid level probe ............................................................23

Dead zones for ammonia ................................................24

First aid in case of ammonia accidents ..........................25

General .......................................................................25

Basic rules of rst aid ................................................. 25

Inhalation ................................................................... 25

Eye injuries from liquid splashes or concentrated vapor

Skin burns from liquid splashes or concentrated vapor ..

Protecting the environment ........................................25

Additional facts about refrigerants ............................. 25

Additional facts about R-717 .....................................25

RDC unit prestart checklist .............................................. 26

170.200-IOM (FEB 23)

Page 3

Remote Distributed Condensing Units (RDC)

Installation - Operation - Maintenance

General Information

Preface

This manual describes the installation, operation, and

maintenance procedures for remote distributed condens-

ing (RDC™) units. This includes:

• Dangers resulting from the failure to comply with safety

pre-cautions when operating the equipment and per-

forming maintenance tasks.

• How to start, operate, and stop the equipment safely.

• How to respond when problems occur during

operation.

• Scheduled maintenance tasks for the equipment and

when and how to carry them out safely.

To prevent accidents, ensure only authorised personnel

carry out the assembly and disassembly of components.

Notice

It is important that the operating personnel famil-

iarize themselves with the contents of this manual

in order to ensure proper and efcient operation.

Johnson Controls is not liable for damage occurring

during the warranty period where this is attributable

to incorrect operation.

It is important to

correctly apply

these compressors

to an

adequately controlled refrigerant or gas system. Consult

your authorized Johnson Controls-FRICK representative for

expert guidance in this determination.

Proper performance and continued satisfaction with these

units is dependent upon:

• Correct installation

• Proper operation

• Regular and systematic maintenance

• Proper package and system engineering

To ensure correct installation and application, select

the appriopriate equipment and connect to a correctly

designed and installed system. The engineering plans,

piping layouts, and other system design materials, must

be detailed in accordance with the best practices and local

codes, such as those outlined in ASHRAE and EN literature.

For information related to the function and operation of

other equipment associated with the FRICK Low Charge

Central System (LCCS), refer to the appropriate FRICK

equipment IOMs available electronically on the FRICK

Coolware website or through your FRICK sales ofce.

Notice

Ensure only trained personnel handle and install the

equipment.

Job inspection

Immediately upon delivery, examine all crates, boxes,

and exposed component surfaces for damage. Unpack all

items and check against shipping lists for any discrepancy.

Examine all items for damage in transit.

Transit damage claims

The consignee must make all claims. This is an ICC re-

quirement. Request immediate inspection by the agent

of the carrier and be sure to execute the proper claim

forms. Report damage or shortage claims immediately to

Johnson Controls-FRICK Sales Administration Department,

in Waynesboro, PA.

RDC unit identication

Each RDC unit has an identication data plate containing

unit model, serial number, and Johnson Controls-FRICK

sales order number, located on the subcooler mounting

plate.

Notice

When inquiring about the unit, or ordering repair parts,

provide the model and serial number

from the data

plate (see Figure 1),

and the Johnson Controls

-FRICK

sales order number.

Figure 1: Identication data plate RDC units

170.200-IOM (FEB 23)

Page 4

Remote Distributed Condensing Units (RDC)

Installation - Operation - Maintenance

Figure 2: RDC™ Remote distributed condensing unit

RDC units

The FRICK LCCS is designed around the use of RDC mod-

ules, supporting control systems and DX evaporators. With

this design, the condensing load is decentralized, thereby

reducing the refrigerant charge in a facility by up to 80% in

comparison to conventional pumped recirculation systems.

The RDC module design also eliminates the need to install

large liquid storage vessels and run central liquid refrig-

erant lines in occupied spaces of the facility promoting

safe operation of the equipment. RDC units work with the

FRICK patented LCCS system design and controls, making

it among the safest, most reliable, and energy-efcient

refrigeration systems on the market.

Standard RDC modules, available from 20 TR to 250 TR

and 300 psi DWP, operate in ammonia process applica-

tions and standard freezers, coolers, or dock applications

with hot-gas or air-defrost capability. Standard yet ex-

ible, the RDC modules operate with two or more DX style

evaporators and have options for stainless steel package

piping and CRN registration.

When appropriate, the RDC unit comes with a package

mounted 460 V disconnect panel, and a 460 V or 120 V

transformer, eliminating the need to run a separate 120 V

power for the control panel and associated I/O. FRICK RDC

units enable a low-cooling system refrigerant charge and

simultaneously provide a high efciency cooling capacity.

The RDCs are lightweight enough that, in most cases, they

do not require special structural steel roof support result-

ing in low installation costs.

Condenser system

The RDC modules can be close-coupled with an adiabatic

style condenser that combines the simplicity of an air-

cooled condenser with increased efciency during higher

ambient temperature conditions, or a small, lightweight

glycol plate-style condenser. RDC unit adiabatic con-

densers are manufactured with stainless steel tubes with

aluminum ns that may be epoxy coated for additional

chemical resistance.

The adiabatic condenser option offers up to 90% water

savings in comparison to conventional evaporative-style

condensers by using water only on high ambient tem-

perature days when it’s necessary. Using the latest heat

transfer and control technology, the Adiabatic Cooling De-

livery System combines a water management system and

cooling pads. This optimizes adiabatic efciency, minimizes

water consumption, and safely manages water usage.

Dry coils and effective water management help to reduce

the risk of legionella, pneumophilia and other associated

respiratory illnesses.

The wetted cooling pads pre-cool the air entering coils

during peak air temperatures. This lowers the air tempera-

ture closer to the wet bulb temperature without wetting

the ns. This signicantly increases the thermal efciency

of the unit with minimal water consumption.

Subsequently, the increase in thermal efciency at peak

temperatures also leads to lower operating costs. Using

humidication pads also protects the coils from dirt and

debris and are easily removable for maintenance.

RDC unit adiabatic condensers use electronically com-

mutated (EC) fans for low-energy consumption and more

Callout Description Callout Description

A Liquid storage vessel B Adiabatic condenser

C RDC PLC I/O panel - -

170.200-IOM (FEB 23)

Page 5

Remote Distributed Condensing Units (RDC)

Installation - Operation - Maintenance

precise control of condensing capacity.

The RDC unit uses an optional glycol plate-style condenser

which incorporates thermal efciency and reliability with

the potential benet of additional heat recovery capability.

Process heat recovery results in immediate and potentially

signicant cost savings that lower operating costs and

increases overall protability.

RDC glycol plate condensers are designed to ASME VIII,

Division 1 standards and use corrosion resistant 316 stain-

less steel plate material with highly engineered chevron

plate patterns for optimal heat transfer. Specialized plate

geometry provides low pressure drop and low fouling

while delivering high thermal efciency. Semi-welded

plate heat exchanger gasketed joints use EDPM and HNBR

elastomers for industrial reliability while offering easy

disassembly for maintenance and serviceability.

The highly efcient glycol plate heat exchangers are com-

pact allowing RDC units to handle large heat loads while

maintaining a small footprint and low refrigerant charge.

Liquid storage vessel

The liquid storage vessel (LSV) is designed and con-

structed in accordance with ASME Section VIII, Divison 1

and outtted with dual 300 psi rated safety relief valves.

The LSV provides a constant pressure liquid refrigerant in

order to properly feed the evaporators. Condensed refrig-

erant ashes down to an intermediate pressure and the

vapor separates from the liquid inside the LSV. Control of

the LSV pressure is accomplished by using a dual pressure

regulator. The ash gas maintains liquid pressure inside

the LSV to feed the DX evaporators and the excess vapor

ows to either the economizer port of the screw compres-

sors for increased system efciency, or to one of the main

suction lines.

The pressure setting of the back pressure regulator con-

trolling the LSV varies according to system design. Refer

to the sales order P&ID for the design pressure set-point.

The secondary standby pressure set-point of the pressure

regulator is to provide relief for rising pressure inside the

vessel before reaching the set-point of the safety relief

valves mounted on the vessel. A typical scenario would

be rising pressure inside the liquid lled vessel from direct

exposure to the sun. The standby pressure is commonly

set at 200 psig but may vary.

The LSV is equipped with a guided microwave wire-style,

liquid level transmitter as part of the liquid refrigerant level

control. A mechanical high level oat switch provides high

LSV liquid level protection for compressors.

RDC control panel

Each RDC has a factory-mounted, Nema 4 Remote I/O

control panel built to UL-508A standards. The RDC control

panels use 24 VDC control modules to provide smaller,

safer ARC Flash compliant controls. Refrigeration System

Control PLC is programmed to manage LSV refrigerant

levels in the critically charged LCCS system for the entire

facility. The RDC panels are factory-wired with most of the

necessary safety and operating devices to provide stable,

efcient, and safe operation of the entire system under

varying loads and operating conditions. The Refrigera-

tion System Control PLC and the RDC I/O panels connect

through the use of Ethernet.

Defrost operation

RDC Units are designed to accommodate either hot gas

defrost or air-cooled defrost applications. The hot gas

supply control valves and defrost condensate liquid return

oat valves are provided as part of the ship loose valve

sets for eld installation. The defrost condensate return

line is designed to return condensed liquid to the LSV dur-

ing the defrost cycle.

The FRICK control system can be programmed to initi-

ate defrost operation in a number of ways including time

elapsed since last defrost cycle, coil temperature, direct or

optical detection of frost buildup, or other methods. While

the mechanism to initiate the defrost cycle may vary, the

hot gas defrost process includes the following basic steps:

1. Pump out phase: The liquid feed valve to the evapo-

rator is closed while the suction line remains open

allowing liquid refrigerant remaining inside the coils

to vaporize and leave the evaporator. This allows heat

from the hot gas supply line to immediately begin

melting the frost build up on the coils. Removing the

liquid refrigerant rst also helps prevent damage to the

coil from pressure shocks or liquid hammer that may

occur as hot gas enters. After the liquid refrigerant is

completely vaporized the evaporator fans are turned

off and the motorized control valve in the line from the

evaporator outlet and the suction line is closed.

2. Hot Gas Phase: Each evaporator equipped with hot

gas defrost has a branch feed line tied into the hot gas

header. This same line also supplies high pressure va-

por to the local condenser. The pressure of the hot gas

must be reduced before entering the evaporators to

prevent damage to the coils. To accomplish this there

is an outlet pressure regulating valve in the evapora-

tor hot gas supply piping. The pressure drop across the

valve is determined by the design defrost temperature

setting used in the defrost cycle. Traditionally, the

defrost cycle temperature is between 40°F and 55°F.

Defrosting at a higher temperature does not gener-

ally improve the defrost efciency because most of the

melting energy is attributed to the hot gas’ latent heat

and not its sensible heat. Higher defrost temperatures

would also mean additional energy is required to cool

the coils back down after the defrost cycle is complete.

For the FRICK LCCS systems, the defrost temperature

and subsequent saturation pressure may need to be

set a little higher in order to create a pressure dif-

ferential between the defrosting coils and the LSV in

order to return condensate liquid to the vessel. Using

a defrost temperatures between 40°F and 55°F means

the discharge pressure supplying the hot gas must be

reduced to between 85 psig to 115 psig. As the hot gas

cools and then condenses it transfers heat to melt the

frost. A liquid return oat valve at the outlet of the coil

routes the condensate back to the LSV. This process

continues until either a time limit is reached or a tem-

perature sensor terminates the defrost cycle.

170.200-IOM (FEB 23)

Page 6

Remote Distributed Condensing Units (RDC)

Installation - Operation - Maintenance

3. Equalization: After the defrost process is complete,

the hot gas supply is stopped by shutting the hot gas

solenoid valve while the motorized control valve on

the suction line is slowly opened. This allows the coil

temperature to drop and its pressure to equalize,

freezing any water droplets remaining on the outside of

the coils rather than blowing them into the refrigerated

space. After a predetermined time delay, the evapora-

tor fans can be restarted and the refrigeration cycle

can be resumed.

Note: Air defrost is used for room temperatures above

the freezing point of water. The liquid feed valve

to the evaporator is closed while the suction line

remains open. This allows liquid refrigerant to

vaporize and leave the evaporator. During this time

the evaporator fans continue to run. The warmer

air owing over the coil causes the ice to melt.

Pipe sizes for hot gas supply lines and condensate return

lines are available from the P&ID drawings (see Figure 3a

and Figure 3b. This drawing also contains some additional

guidelines for the eld erected piping to ensure safe and

reliable operation.

The defrost hot gas line sizes provided are based on tables

in the IIAR Ammonia Refrigeration Piping Handbook. The

primary defrost hot gas supply piping is sized on the basis

that only one evaporator is defrosted at a time and the sin-

gle highest capacity evaporator on that supply main is used

for that sizing. Similarly, hot gas lines running to individual

evaporators are sized based on their individual capacities.

One of the main considerations for the hot gas supply

line is keeping it free of liquid refrigerant. Liquid laying in

hot gas piping can form a liquid slug when gas begins to

ow. Particular attention must be paid to insulating the

line, even where it may run inside the building through

cold spaces. The hot gas defrost lines to the evaporator

control valve groups should also be insulated. The install-

ing contractor can choose to add liquid drains or traps and

to pitch the hot gas line back towards the drains to collect

any unwanted liquid. Any collected liquid refrigerant can

be returned to the LSV or low pressure receiver.

Cold weather operation

Adiabatic condensers used on the RDC units are dual coil

designs with separate inlet and outlet refrigerant connec-

tions. Individual oat valves are located on the refrigerant

outlet connections for each coil. This is done to mitigate

the effects of coil pressure differences during cold weather

operation.

Refrigerant expansion valve

The RDC units use a Danfoss valve station or series of

valves containing a refrigerant expansion valve serving the

direct expansion evaporators. The motorized expansion

valve has a non-contact magnetic coupling that transmits

the driving force from the actuator through the stainless

steel top housing, which means a packing gland is not

required. The magnetic coupling transfers torque through

a spindle, providing vertical movement for the piston and

the valve seat which opens and closes the valve. When

the valve is in the closed position, the closing force of the

actuator, valve seat, and valve plate provide an effective

seal. There is a solenoid valve upstream of the motorized

expansion valve. Its purpose is to serve as a means to stop

refrigerant ow to the evaporator in the event of a power

outage.

170.200-IOM (FEB 23)

Page 7

Remote Distributed Condensing Units (RDC)

Installation - Operation - Maintenance

Figure 3a: Evaporator piping hot gas defrost

Figure 3b: Evaporator piping air defrost

170.200-IOM (FEB 23)

Page 8

Remote Distributed Condensing Units (RDC)

Installation - Operation - Maintenance

Figure 4: Piping and instrumentation diagram

170.200-IOM (FEB 23)

Page 9

Remote Distributed Condensing Units (RDC)

Installation - Operation - Maintenance

Pressure regulators

Pressure regulators are used on RDC units in two different

areas; to regulate the pressure of the LSV and to serve as

a means to pressurize the LSV upon system startup in cold

weather.

In the vapor outlet line of the LSV, a dual back pressure

regulator is used to maintain a constant pressure. It also

serves as a primary pressure safety relief in situations

where the rooftop vessel pressure may rise due to expo-

sure of the refrigerant charge to direct sun.

The low pressure setting on the inlet pressure control

module is set to maintain the operating pressure of the

LSV, usually 85 psia to 105 psia. This provides sufcient

pressure to drive liquid refrigerant from the vessel to the

DX evaporators, overcoming pressure drops in the refrig-

erant lines, across the electronic refrigerant expansion

valve, and the evaporator distributor. When the solenoid

on the regulator is energized, inlet pressure enters the

valve and is fed to the inlet pressure control module with

the lower setting. As pressure rises above the pressure

setting on the control module, the refrigerant pressure

pushes on the top of the valve piston opening the valve

and modulating the inlet pressure.

Figure 5: Outlet pressure regulator

SERVICE CLEARANCE

3 in.

SERVICE

CLEARANCE

3 in.

SERVICE CLEARANCE

COIL SUPPLIED

SEPARATELY

SEE DWG: 951A0154

1.19

in.

Valve station

part number

(in.)

950A0405H01 13.2 4.4 10.4 3.4 6.3

950A0405H02 13.2 4.4 10.4 3.4 6.3

950A0405H03 15.9 6.3 10.5 3.3 6.1

950A0405H04 15.9 6.3 10.5 3.3 6.1

950A0405H05 18.8 6.4 11.4 3.5 6.2

Figure 6: Dual pressure regulator (showing solenoid coil)

When the solenoid de-energizes the inlet pressure is di-

rected to the higher setting inlet pressure control module.

This control module is set at 200 psig and is intended

to act as a safety bypass when the vessel pressure rises

above operating pressure. If pressure in the vessel exceeds

the 200 psig setting, the refrigerant pressure pushes on

the top of the valve piston, opening the valve and modu-

lating the inlet pressure.

Note: If the vessel pressure continues to rise, it is protected by the

external ASME required safety relief valves.

In the refrigerant line out of the evaporator, a Danfoss

motorized valve regulates evaporating pressure. There is

a line connecting the vapor inlet and the LSV. This line

contains a valve station. The valve station contains stop

valves, a solenoid, a pressure regulator, and a check valve.

The pressure regulator is an outlet pressure regulator.

The purpose of this line and valve station is to establish

pressure in the LSV quickly during startup. This is most

important during cold weather because the refrigerant in

the LSV has a lower saturation pressure during periods of

non-operation.

High pressure regulating system

The LCCS control system modulates the condenser capac-

ity at each RDC package to continuously redistribute the

liquid refrigerant charge between the RDCs in the system

while simultaneously achieving the lowest allowable system

condensing pressure. Control the capacity of each adiabatic

condenser by modulating the condenser's vapor inlet valve

and controlling the fan speed. Control the plate condenser

capacity by modulating the ow of refrigerant vapor and

glycol to each individual condenser along with modula-

tion of the uid cooler capacity to produce the appropriate

incoming glycol temperature.

Mechanical oat valve

The mechanical oat valve (Figure 7) is mounted on the

condenser liquid outlet and passes only liquid from the

high pressure side of the system to the RDC controlled

pressure LSV.

Figure 7: Mechanical oat valve

170.200-IOM (FEB 23)

Page 10

Remote Distributed Condensing Units (RDC)

Installation - Operation - Maintenance

The oat valve has a valve seat bypass (Position 1). This

ensures that a pressure equalization occurs at standstill

between the high pressure condensing side and the lower

pressure LSV side, with a subsequent emptying of liquid

from the oat housing. The hole is placed below liquid level,

but note that a small amount of liquid may be left when

dismantling the oat vessel. There is a vent valve located in

the middle of the end cover of the oat housing that allows

access to the top of the oat housing through a tube.

Liquid refrigerant subcooler

Liquid Refrigerant fed from the LSV is subcooled before

owing to the electronic expansion valves at the DX evapo-

rators. The subcooling offsets pressure drop in the refriger-

ant lines and ttings that could potentially cause the liquid

refrigerant to ash before reaching the expansion valves.

The factory mounted subcooler is a fully welded plate style

heat exchanger constructed of 316L stainless steel plate

material and rated for 350 psig design working pressure.

The heat exchanger is fed by a small motorized valve to

deliver approximately 10°F of subcooling. The motorized

valve is controlled by a proportional integral loop based on

superheat and degree of subcooling.

Liquid level probe

The RDC units are equipped with a guided microwave liquid

level transmitter. It measures refrigerant level by measuring

the distance above the liquid level of the refrigerant. The

transmitter probe detects this level change and converts it

into a proportional output signal of 4mA to 20 mA signal.

The sensor is set up so that the 4mA to 20 mA signal cor-

responds to the probes measuring range, excluding the

dead zones.

Float switch

The RDC units also have a mechanical oat switch with a

hermetically sealed switch assembly on the LSV for refrig-

erant level control. The switch is UL listed and rated for

400 psi design working pressure. The oat switch acts as

a safety and closes the modulating vapor feed valve to the

condenser and signals an alarm if a high level of refriger-

ant is detected in the LSV. This stops the liquid level in the

LSV from rising, in order to prevent liquid refrigerant from

entering the compressor.

The liquid level probe and oat switches are essential ele-

ments in the RDC control strategy to manage liquid level in

the system while operating conditions are changing.

Figure 8: Float switch

170.200-IOM (FEB 23)

Page 11

Remote Distributed Condensing Units (RDC)

Installation

FRICK RDC units are roof-mounted equipment. With a low

weight to footprint ratio, in most cases the units can be

installed on customer-provided equipment rails without

the need for additional structural steel support of the

roof. Unit weights are available from general arrangement

drawings. Consult a certied structural engineer to ensure

the existing roof or new roof design is adequate to sup-

port the load.

The FRICK RDC unit does not contain any rotational or

normal package vibrational loading that would require

special mounting isolation or anchoring. However, because

the roof top equipment contains ammonia, it is important

to securely attach the package to the building's structural

steel to prevent movement due to the inuence of wind

or seismic activity. It is the responsibility of the design

engineer and installing contractor to ensure that adequate

support and attachments are available to meet all local

codes and industry guidelines.

Notice

Allow space of a minimum of 24 in. (610 mm) for

servicing on all sides of the unit.

Notice

Securely attach the rooftop RDCs to the building

structural steel in accordance with potential wind and

seismic inuences.

Handling and moving

Warning

Improper handling may cause serious injury or

death.

• Use a crane and rigging whenever moving the unit.

• Do not use a forklift to move the unit.

• Refer to the engineering drawings provided with the

unit for shipping weight and location of the center of

gravity.

Note: The center of gravity may not be located in the cen-

ter of the package and the unit may be top heavy.

To facilitate the lifting and rigging of the package, the

base assembly uses ASTM A 572 high strength low alloy

channel steel or SA 36 hot rolled channel steel to provide

the strength and rigidity needed to support the unit during

installation.

1. Determine the number and location of lifting lugs, de-

pending on your conguration, which provide balance

during the lift and minimize base deection.

2. Lift the unit using all of the lifting lugs welded to the

base.

3. Use spreader bars and balancing chains to prevent

instability and damaging or straining piping, instrumen-

tation, vessels, or panels mounted on the unit.

Note: Another supplier must provide the shackles and

screw pins.

4. Use balancing chains, cables, or straps in both direc-

tions to prevent load shift and instability during rigging.

All hooks, cables, and spreader bars must meet the

manufacturer’s recommendations and must not be

overloaded.

5. A good practice is to impose an imbalance by se-

quentially adding weight to each corner and carefully

observing the load reaction to make sure the load does

not shift.

6. Adjust cables and chains accordingly to ensure that the

equipment is stable and lifted level.

Ensure only a qualied operator performs the lifting, who

must exercise extreme care to check the level and stability

of the load before lifting the load more than a few inches.

Caution

The RDC units are not intended to be picked up using

forklifts and doing so may lead to excessive defor-

mation of the base and permanent damage to the

mounted equipment.

Refer to OSHA Safety and Health Standards (29 CFR 1910),

Sections 1910.179 and 1910.184.

Relief valves and piping

RDC pressure relief valve piping must meet minimum

height requirements as specied by local building codes

and applicable regulatory codes. The RDC does not usually

ship from the FRICK factory with this piping in place. It is

the responsibility of the installing contractor to provide

this piping on site.

Conduct the inspection of vessels and safety valve compo-

nents, and changeout of safety valves in accordance with

IIAR-6 requirements.

Installing the refrigerant expansion

valves

1. Install the motorized expansion valve and its actuator

in horizontal lines with the actuator body in the vertical

position.

• The actuator uses a hermetic, magnetic coupling for

easy removal from the motorized valve.

• The top cover on the valve can rotate 90° in any

direction without affecting the valve function.

2. Remove the top cover and function modules before

welding to avoid damage to o-rings and the valve seats

in the valve station.

3. Thoroughly clean the valve body after welding to avoid

damage from debris.

170.200-IOM (FEB 23)

Page 12

Remote Distributed Condensing Units (RDC)

Installation

Insulating

In low charge refrigeration systems, even small amounts of

liquid refrigerant laying in system piping and out of circu-

lation can impact system operation. You must insulate all

refrigeration piping as indicated on the P&ID. This includes

the high pressure vapor discharge piping. The FRICK RDC

package is not factory insulated.

You must also insulate the LSV, and all package piping and

control valves, on site as indicated on the P&ID to prevent

refrigerant vapor from condensing.

Holding charge and storage

Each RDC™ unit is pressure and leak tested at the factory

and thoroughly evacuated and charged with dry nitrogen

to ensure the integrity of the unit during shipping and

short-term storage before installation.

Notice

Take care when opening the package piping to ensure

that the nitrogen charge is safely released.

Warning

Holding-charge shipping gauges on the unit are

only rated for 30 psig and are for verifying the

dry-nitrogen shipping charge. They are not com-

patible with ammonia

Remove the holding-charge shipping gauges before pres-

sure testing the system and before charging the system

with refrigerant.

Warning

Failure to remove these gauges may result in cata-

strophic failure of the gauge and uncontrolled release

of refrigerant resulting in serious injury or death.

Keep all units in a clean, dry location to prevent corro-

sion damage. Reasonable consideration must be given to

proper care for the components of the panel and related

instrumentation.

For units stored for more than two months, check their ni-

trogen charge periodically. If the unit has an adiabatic con-

denser, cover it to protect it from dust, dirt, and moisture.

Visually inspect units to verify that all components are

intact, undamaged, and that the conguration is consistent

with the sales order requirements. Inspect temporary cov-

erings such as tarps or shrink wrap to ensure they are not

trapping water in contact with the equipment. Check enclo-

sures for accumulated water and drained as applicable.

Visually inspect the unit for rust, paint fade, paint blisters,

and surface imperfections that may have occurred as a

result of handling and storage damage. The paint may in-

dicate some visual, not functional deterioration, especially

epoxy paint coatings. Purchase touch-up paint from the

FRICK Parts Center.

RDC units are evacuated and placed under a regulated dry

nitrogen purge pressure of 5 psig to 15 psig. Gauges are

installed in the appropriate locations to conrm that the

nitrogen pressure is still present. Verify the reading on

the gauges every two weeks. If in the rst three months

of storage inspection records indicate a repetitive loss of

nitrogen charge, contact the FRICK service department.

Power supply and electrical wiring

RDC units with adiabatic condensers require 460 V power

supply, provided by the customer, for operation of the

condenser fans. A factory mounted 460 V disconnect along

with a 460 V/120 V transformer provide the RDC unit with

control power. In addition, the RDC panel also has a 120 V/

24 V transformer mounted internally to provide the neces-

sary power for the 24 V control valves. Field electrical

power wiring consists of routing to the RDC mounted dis-

connect and then to the adiabatic condenser power panel.

All control valves mounted on the RDC unit are factory

wired.

Wiring between the RDC unit and the condenser, the

evaporators, the evaporator control valves, and associated

sensors is eld wiring.

External wiring connections to establish after installing the

RDC unit include, but are not limited to:

• Ethernet with the refrigeration system control

• Ethernet with the adiabatic condenser (as applicable)

• Glycol pumps (as applicable)

• Evaporator EC fan motor analog speed signa

• Evaporator EC fan motor power is separate eld wiring

• Room air temperature sensors

• Ammonia leak sensors

• Evaporator modulating liquid feed valves

• Evaporator modulating suction valves

• Evaporator suction temperature and pressure sensors

Electrical grounding

Grounding is the most important factor for success-

ful electronic controls operation and is usually the most

overlooked. The National Electrical Code (NEC) states that

control equipment can be grounded by using the rigid

conduit as a conductor. This worked for the earlier relay

control systems, but it is not acceptable for today’s elec-

tronic control equipment. Conduit is made of steel and is

a poor conductor relative to an insulated stranded copper

wire. Electronic equipment reacts to very small currents

and electrical potentials, and must have a proper ground

in order to operate awlessly. Carefully designed stranded

copper grounds are required.

For proper operation, the control power ground circuit must

be a single continuous circuit of the properly sized insulated

stranded conductor, from the electronic control panel to the

plant supply transformer earth ground bus (see Figure 3).

Driving a ground stake at the electronic control may cause

additional problems because other equipment in the plant

on the same electrical circuit can ground themselves to that

same ground stake and generate large ground ow at the

sensitive electronic control panel.

170.200-IOM (FEB 23)

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Remote Distributed Condensing Units (RDC)

Installation

Notice

Though not always required, separate insulated

continuous ground wires back to plant (site) earth

ground provide clean grounding for all controls and

instrumentation.

Running multiple ground conductors into an electronic

control panel from various locations can introduce multiple

electrical potentials resulting in ground loop currents.

A single continuous ground wire (10 AWG or 8 AWG) from

the electronic control panel neutral bus bar, that is then

bonded to the control power neutral on the secondary

side of the control power stepdown transformer yields the

best results. Using a separate, correctly sized insulated

conductor, connect that secondary side neutral to the

site’s 3-phase earth ground.

Figure 8: Control panel ground circuit

Notice

Structural grounding can also result in multiple

ground potentials and is a relatively unreliable con-

ductor. The use of structural grounding is not accept-

able for proper operation of electronic equipment.

A ground conductor is required for 3-phase power wiring.

For safety purposes, this conductor must at least be sized

in accordance to the NEC and any local codes relative to

the highest rated circuit overload protection provided in

the circuit. Any given manufacturer may require a larger

ground conductor than what is required by the NEC for

proper steering of electromagnetic interference (EMI) from

sensitive circuits. This conductor must also be insulated

to avoid inadvertent contact at multiple points to ground,

which could create ground loops. In many installations

with electronic control problems, this essential wire is

missing, is not insulated, or is incorrectly sized.

NEC size ratings are for safety purposes and not neces-

sarily adequate for relaying EMI noise to earth ground

and the protection of sensitive equipment. Sizing 3-phase

ground conductors one to two sizes larger than required

by the NEC code provides better transfer of EMI noise and

protection of sensitive electronic equipment.

FRICK requires that the ground conductor meet the fol-

lowing:

• Stranded copper

• Insulated

• One size larger than NEC requirements for conventional

starters

• Two sizes larger than NEC requirements for VFD start-

ers

• Conduit must be grounded at each end

• The ground circuit must be continuous from the motor

to the starter/drive and then from the motor/drive to

the plant supply transformer (power source)

VFD applications

For applications involving VFDs, isolation of the control

power, analog devices, and communications ground from

the 3-phase power ground within the starter and the elec-

tronic control panel is necessary. This is due to the higher

noise (RFI/EMI) levels generated between the VFD output

and the motor, relative to a conventional starter. If these

grounds are consolidated by a common back-plate or bus

bar in the starter/drive, this noise can be direct coupled

to the control power, analog device, and communications

grounding and may cause unexplained behavior and pos-

sible damage to components.

Notice

Where VFDs are involved, FRICK requires that control

and instrumentation grounds be kept separate from

electrical power grounds.

To install correctly, run a separate, properly sized (10 AWG

or 8 AWG) insulated wire to earth ground in addition to

the 3-phase power ground back to the 3-phase supply

transformer (plant). This means electrically isolating the

3-phase power ground and the control ground, except for

the connection at the plant supply transformer.

Proper grounding as described here steers any EMI/RFI

noise to earth ground, reducing the potential for it to af-

fect the sensitive control equipment.

170.200-IOM (FEB 23)

Page 14

Remote Distributed Condensing Units (RDC)

Installation

Figure 9: Abiabatic RDC

170.200-IOM (FEB 23)

Page 15

Remote Distributed Condensing Units (RDC)

Installation

Figure 10: Plate condenser RDC

170.200-IOM (FEB 23)

Page 16

Remote Distributed Condensing Units (RDC)

Installation

Figure 11: Evaporator piping arrangement

170.200-IOM (FEB 23)

Page 17

Remote Distributed Condensing Units (RDC)

Installation

Table 1: LCCS RDC 135A Legend

CV Check valve PI Pressure indicator

DIR Direct acting PIC Pressure indicating

controller

FLS Level switch PSV Pressure safety valve

HFI High pressure oat valve PV Pressure vessel

HX Heat exchanger REV Reverse acting

LAH High level alarm STR Strainer

LAHH High level shutdown TE Temperature element

LI Level indicator TI Temperature indicator

LIC Level indicating control-

ler

TIC Temperature indicating

controller

LP Liquid level probe TXV Thermal expansion valve

MV Motor operated valve YY Solenoid valve

PE Pressure transducer

170.200-IOM (FEB 23)

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Remote Distributed Condensing Units (RDC)

Installation

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170.200-IOM (FEB 23)

Page 19

Remote Distributed Condensing Units (RDC)

Operation

Pre-start checklist

After installing the RDC™ and all connections for refriger-

ant, water and electricity, instruments, and safety switch-

es, proceed as follows.

Pressure testing

The FRICK RDC package arrives pressure tested from the

factory and charged with nitrogen.

Pressure tests of the combined equipment and piping

system to pressures appropriate for the design working

pressure (DWP) of the system are necessary before evacu-

ation and charging with refrigerant.

Follow the pressure testing procedures as outlined in the

current IIAR guidelines and all applicable local codes.

Evacuation

It is important to thoroughly evacuate the FRICK RDC and

associated condenser, piping, and evaporators in order to

remove all moisture and non-condensables before intro-

ducing R717 refrigerant, eliminating operational problems

resulting from these issues. Evacuation can be done to the

entire piping system or in sections.

Note: It is assumed that all components and piping for the

system have been installed and pressure tested in

accordance with recognized and generally accepted

good engineering practices (RAGAGEP).

Table 2: Equipment

Qty. Description

1Vacuum pump capable of creating a vacuum of

1 mm Hg Abs.

1 set Certied charging / evacuation lines complete

with necessary valves suitable for R717.

To evacuate, perform the following steps:

1. Open all appropriate isolation and bypass hand valves

to facilitate a common zone for the evacuation.

2. Manually open all solenoid valves and pressure regula-

tor valves.

3. Manually open all motorized valves.

4. Manually open the condenser refrigerant drainer.

5. Begin pulling a vacuum on the RDC and the piping

system:

a. Draw down to between 5 in. Hg and 10 in. Hg

b. Break this vacuum with nitrogen gas to between 0

psig and 5 Psig

6. Release the excess nitrogen gas and draw a second

vacuum, this time down to between 10 in. Hg and 15

in. Hg.

7. If the piping system seems to be dry and easily drawing

down, increase the vacuum to 1,000 microns. Oth-

erwise, charge a second time with nitrogen, purge,

and draw a third vacuum. The goal is to reach a 1,000

micron vacuum that does not rise more than 500 mi-

cron in an hour. This indicates a dry non-condensable

free piping system. If a leak occurs, check the following

areas:

• Valve packing

• Vacuum pump connections

• Defective stop valves (not tightly shut off the atmo-

sphere

8. After rectifying any leaks, repeat the above steps to

draw back down into a vacuum. When the vacuum

pressure can be held at 1,000 microns without rising

more than 500 microns in a one hour period as called

for in Step 6, the system is considered dry and ready

for refrigerant charging.

9. If plans are to delay charging with refrigerant, pres-

surize the piping system with 5 psig to 15 psig of dry

nitrogen.

Pre-commissioning: Pre-initial start-up

The FRICK RDC packages become operational hubs for the

FRICK LCCS. Start-up of the package is closely integrated

with the startup and operation of the associated equip-

ment. Before commissioning the RDC, use the following

list to systematically conduct a system pre-start check of

all associated equipment essential to the operation of the

RDC.

Associated LCCS equipment checklists to follow:

• FRICK Control System Pre-start Check List

• FRICK and/or Guntner Evaporator Pre-start Checklist

• Other Process Related Evaporator Pre-start Checklist

• Guntner Adiabatic Condenser Pre-start Checklist, if

applicable

• Alternate Secondary Refrigerant Circulation Pre-start

Checklist

• Alternate Evaporative Condenser Pre-start Checklist

• Purger Pre-start Checklist – If Applicable (Purger by

Others)

• Compressor Package Pre-start Checklist

To conduct the pre-start check, perform the following

steps:

1. Check all the control system outputs and their associ-

ated endpoint automation devices. These are outputs

from the RDC PLC I/O panel. For the starter/VFD opera-

tion, check the following:

• Digital start outputs

• Analog speed outputs

• Condenser and evaporator fan rotations

• Control valve solenoid operations

• Motorized valve analog signals and direction of

movement

• Liquid level analog signal and direction

170.200-IOM (FEB 23)

Page 20

Remote distributed condensing units (RDC)

Operation

2. Calibrate the following:

• Pressure sensors

• Temperature sensors

• Level columns

• For Motorized valve actuators:

a. Check actuator orientation and torque the attach-

ment screws.

b. Program the actuator for the actual valve for

operation.

• VFD analog speed signals (EC motor speed signals)

3. After the system is operating, set the following pres-

sure regulators per the FRICK information on the

system P&ID:

• LSV ash gas relief back pressure regulator

• LSV hot gas pressurization outlet regulator

• Defrost hot gas feed outlet pressure regulators

• Individual evaporator suction back pressure

regulators

When nally ready to charge with refrigerant, release the

nitrogen and pull down the now dry piping system to 28 in.

to 30 in. of vacuum before introducing the refrigerant.

Charging with refrigerant and initial start-up

Notice

Adding refrigerant to the RDC unit must be conducted by

a licensed, trained technician that is qualied to operate

Industrial Refrigeration systems. Reference ANSI/IIAR

Standard 5 for additional requirements.

It is important to perform the commissioning steps above

before attempting to charge the RDC with refrigerant.

Attempting to operate the RDC without these calibrations

may result in signicant system upsets.

Charging with refrigerant consists of two steps:

1. Initial pressurization with vapor

2. Charging with liquid refrigerant.

Ensure the charging hose is suitable in size and duty, and

conduct the procedure in a well ventilated area. Cylinders

must be used to charge each RDC package. Avoid combin-

ing cylinders.

Before charging with R717 refrigerant, complete all electri-

cal checks.

In order to avoid severe temperature shock on the unit,

liquid refrigerant must not be charged into the system

until the pressure reaches 59 psig, which corresponds to

40°F (4.4°C) saturated. Use refrigerant vapor to break the

vacuum and raise the pressure to this level.

1. Connect the charging hose to the unit charging valve

and the R717 refrigerant cylinder of the RDC package to

be started rst.

Note: The charging hose must be clean, dry, and free of

non-condensable gases to prevent moisture enter-

ing the system. Only use vapor from the top of the

cylinder to break the system vacuum and raise the

pressure.

2. Open the charging valve on the package and the

refrigerant cylinder to allow refrigerant vapor to enter

the system. Incrementally increase the pressure slowly

(5 psi to 10 psi steps) while checking the entire system

for ammonia leaks. Sulphur sticks can be used to help

identify ammonia vapor.

3. After the LCCS has reached 59 psig, isolate all the RDC

packages from the system, except for the rst package

to be started.

4. Set all control valves to their normal operating condi-

tion. This includes, but may not be limited to:

• Pressure regulators

• Modulating valves

• Liquid drainers

• Solenoid valves.

5. Close all bypass hand valves and normally closed stop

valves.

6. Set the LSV ash gas outlet back pressure regulator at

house suction for the next step.

7. Start the compressor and maintain minimum load. This

draws down the pressure in the suction main and the

LSV.

8. Allow the associated condenser to begin condensing

high stage discharge gas and the drainer to empty into

the LSV.

9. Introduce liquid refrigerant into the LSV until the liquid

level slightly exceeds (~ 3 in. above) the factory dened

initial operating level.

10. After the liquid level is obtained in the LSV, close the

charging valve and properly bleed any excess refriger-

ant.

11. Set the LSV back pressure regulator (BPR) to the FRICK

indicated pressure, allowing the RDC to provide liquid

to the system low side. Set the LSV minimum pressure

outlet pressure regulator (OPR) to the FRICK indicated

pressure as well.

12. Set the evaporator liquid feed valves for automatic

operation and allow the evaporators to begin cooling.

13. Perform Steps 1 through 12 for all the remaining RDC

packages.

Adding additional charge to an operating LCCS system is

possible by adding liquid into any LSV or by introducing

ammonia vapor into the compressor suction.

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Frick RDC Remote Distributed Condensing Units Installation Operation and Maintenance Guide

Frick RDC Remote Distributed Condensing Units Installation Operation and Maintenance Guide

Frick RDC Remote Distributed Condensing Units Installation Operation and Maintenance Guide

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