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 denitions
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 identication ...................................................... 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
25
Skin burns from liquid splashes or concentrated vapor ..
25
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 efcient 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 ofce.
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 identication
Each RDC unit has an identication 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: Identication 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-efcient
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 efciency 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 efciency 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 efciency, 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 signicantly increases the thermal efciency
of the unit with minimal water consumption.
Subsequently, the increase in thermal efciency at peak
temperatures also leads to lower operating costs. Using
humidication 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 efciency and reliability with
the potential benet of additional heat recovery capability.
Process heat recovery results in immediate and potentially
signicant cost savings that lower operating costs and
increases overall protability.
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 efciency. 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 efcient 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 outtted 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 efciency, 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,
efcient, 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 efciency 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 sufcient
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
B
A
G
6
SERVICE CLEARANCE
4
SERVICE CLEARANCE
3 in.
SERVICE
CLEARANCE
3 in.
SERVICE CLEARANCE
COIL SUPPLIED
SEPARATELY
SEE DWG: 951A0154
F
E
1.19
in.
in.
in.
Valve station
part number
A
(in.)
B
(in.)
E
(in.)
F
(in.)
G
(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
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 certied 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 inuence 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 inuences.
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 conguration, which provide balance
during the lift and minimize base deection.
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 qualied 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 specied 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 conguration 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 conrm 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)
Page 13
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)
Page 18
Remote Distributed Condensing Units (RDC)
Installation
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170.200-IOM (FEB 23)
Page 19
Remote Distributed Condensing Units (RDC)
Operation
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 Certied 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 qualied 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 signicant 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 dened
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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