Northwind MAC1211 Engineering, Installation And Service Manual

Brand: Northwind

Model: MAC1211

Category: Split-system air conditioners

Type: Engineering, Installation And Service Manual

This manual is also suitable for

MAC9034

1291 Brummel Avenue Elk Grove Village, IL 60007 Phone 847-364-8600 Fax 847-364-8601

TABLE OF CONTENTS

General Description ……………………………….. 3

Power Cord Information ……………………………….. 4

Installation Instructions ……………………………….. 4

Standard Features ……………………………….. 5

ACRS (Advanced Condensate Removal System) ………… 6

Electrical Panel & Components ……………………………. 8

Blower-Motor Assemblies ……………………………... 9

Plug/Receptacle Chart …………………………….. 10

Optional Features ……………………………... 11

Applications ……………………………... 14

Replacement Part Procedure ……………………………... 15

Electrical Inspection/Repair ……………………………... 17

Troubleshooting Guide …………………………….. 18

Preventive Maintenance Guide …………………………….. 20

Inside View Belt Drive Units (MAC60-90) ……………….. 21

Inside View Direct Drive Units (MAC12-18) ……………... 22

Wiring Diagrams …………………………….. 23-30

Piping Schematic ……………………………. 31

Specifications ……………………………. 32

Remote Thermostat Option …………………………….. 33

Warranty …………………………….. 36

PAGE

TOPIC

GENERAL DESCRIPTION

GENERAL REQUIREMENTS

IMPORTANT: NorthWind Air Conditioners have been engineered for the comfort of those using them. The ser-

vice life of the units can be extended by following the installation and preventive maintenance instructions.

NorthWind Portable Air-Cooled Air Conditioners are designed and built to cool a wide variety of applications by mov-

ing air through a 12 ½ x 7 inch evaporator discharge grille (Models MAC1211/1811), 18 ½ x 8 (Models

MAC3612/32), 22 x 11½ (Model MAC6012/32/34) and 23 x 11½ (Model MAC9032/34). These self-contained, port-

able units can direct air to specific areas or spots (spot cooling) through optional dual 5 inch diameter nozzles (Models

MAC1211/1811), 6 inch diameter dual nozzles (Models MAC3612/32), 8 inch diameter dual nozzles (Model

MAC6012/32/34) and 10 inch diameter dual nozzles Model MAC90/32/34). The 10 foot cord connected NorthWind

models range from 13,000 BTU/HR to 90,050 BTU/HR moveable floor mount configuration to meet most space re-

quirements. All models are equipped with 2 heavy duty, swivel w/lock front casters and 2 heavy duty fixed rear casters

for easy steering and parking control. MAC60 and MAC90 models have 4 swivel casters with rear swivel locks.

All models include a completely self-contained refrigeration system, air handling system (evaporator and condenser

blowers & motors), air filtration system (electrostatic filters), condensation removal system, and electrical supply and

control system in a professionally designed, neatly arranged heavy duty metal cabinet finished with exterior grade,

weather resistant, high gloss, polyester TGIC powder coating. Only power is required for operation. However, ducting

the condenser air out of the area is recommended. The 24 volt temperature controller provides the desired comfort and

unit control.

NOMENCLATURE

M AC 60 3 2

MOBILE

AIR-COOLED

VOLTAGE

THREE PHASE

CAPACITY

SELECTION

CODE

UNIT MODEL COOLING CAPACITIES

MODEL

BTU/HR CAPACITY

SELECTION

CODE

VOLTAGE

MAC1211 12,000 12 115

MAC1811 16,900 18 115

MAC3612 36,000 36 208/230/1

MAC3632 36,000 36 208/230/3

MAC6012 60,000 60 208/230/1

MAC6032 60,000 60 208/230/3

MAC6034 60,000 60 460/3

MAC9032 90,000 90 208/230/3

MAC9034 90,000 90 460/3

LCDI POWER CORD & PLUG

This air conditioner may be equipped with an LCDI (Leakage Current Detection and Interruption) power cord and plug as

required by US National Electric Code 440.65. The cord consists of a length of shielded flexible cord with no termination on

the load side and an LCDI attachment plug on the line side.

Three phase units are not required to have an LCDI.

The LCDI power cord and plug will remove the supply source via electrical disconnect if the nominal current leakage between

the cord shield and either load conductor exceeds a predetermined value. The cord will remain de-energized until the device

has been manually reset. This is intended to reduce the risk of a fire in the power cord or combustible materials nearby. The

cord shields are not grounded and they must be considered a shock hazard if exposed. The cord shield must not be connected

to ground or to any exposed metal.

The test and reset buttons on the LCDI Plug are used to check if the plug is functioning properly.

To Test:

1. Plug power cord into proper outlet.

2. Press the TEST Button. Circuit should trip, cutting power to the unit and turning the green “POWER READY” light off.

3. Press the RESET Button to restore power: green light should be lit.

TEST

RESET

TEST Button

RESET Button

Front of LCDI Back of LCDI

WARNING:

1. DO NOT press the TEST button while the air conditioner is operating.

2. The TEST and RESET buttons should not be used as “ON” or “OFF” switches.

3. The cord and plug are not intended to offer protection to externally connected loads or

supply circuits.

4. The cord and plug are intended for indoor use only.

INSTALLATION INSTRUCTIONS

BEFORE INSTALLING:

ELECTRICAL REQUIREMENTS:

Unpack the unit, remove it from the pallet carefully and inspect it for any possible shipping damage. All units are

thoroughly run tested and carefully packaged at the factory. If there is any damage, note it on the delivery receipt and

file a claim with the carrier immediately. It is important to read this installation manual carefully. Store this manual

in a safe place for future reference.

Check the data plate on the back panel to make sure the power supply matches the requirements. Refer to

“Specifications” section for voltage and fuse/breaker recommendations. For proper NEMA receptacles, refer to

“Electrical Service Plug/Receptacle Chart.”

Operating the unit on improper voltage will void the warranty.

CAUTION: AN EXTENSION CORD CAN BE USED PROVIDED IT IS RATED AT LEAST 20 AMPS@115VOLTS, or

20 AMPS @ 250 VOLTS WITH GROUNDING-TYPE ATTACHMENT PLUG AND GROUNDING TYPE CONNEC-

TOR (LOAD FITTING).

Do not remove or modify the cord connected LCDI (Leakage Current Detection & Interruption) or AFCI (Arc Fault

Circuit Interrupter). Do not connect the unit to an outlet that is also being used for other electrical appliances or

loads. It may cause nuisance tripping of the LCDI or circuit breaker.

1) Position the unit in the desired location. Make sure that the condenser inlet air grille is not blocked or obstructed

(left side of the unit). Leave at least 8 inches of clearance for proper air flow.

2) Apply the brakes on the front casters to keep unit from rolling or moving out of position.

3) Plug power supply cord into proper receptacle. The green “Power Ready” light should be lit. Push power switch

to “on” position. Turn thermostat dial clockwise (right), to desired comfort number; the unit will start. Rapid turn-

ing of the dial back and forth (short cycling) will activate the unit’s compressor time delay. The unit will not start

until the time delay period (5 minutes) has passed. This safety feature protects the compressor from damage.

This manual is used for guidance and does not form part of a contract. NorthWind, Inc. reserves the right to make

technical changes without prior notice.

1. Always place the unit on a level surface.

2. The unit shall be installed in accordance with national and local wiring regulations.

3. The unit must be connected to a correctly grounded power supply. For safety, this air conditioner is grounded

through the power cord plug when connected to a grounded wall outlet. Do not use an adapter plug or improperly

sized extension cord.

4. Do not install the unit in an area where gas leakage may occur and/or in an explosive atmosphere.

5. Do not apply an insecticide or any type of flammable spray on the unit.

6. Do not start or stop the unit by inserting or pulling out the power plug.

7. The unit is not intended for use by children. Close supervision is necessary if unit is operated near children.

8. Do not insert anything into air inlet or outlet grilles.

9. Do not obstruct air inlet or outlet grilles.

10. If an abnormal odor or smoke comes out of the unit, disconnect the unit immediately and contact a qualified

service technician.

1. Do not immerse the unit in water or any type of liquid.

2. Do not put a stove/grille, etc, where it would be exposed to the direct airflow. It may affect combustion.

3. Do not sit on the unit or place anything on it.

4. Always inspect the power cord for signs of damage before use. If the power cord is damaged, it must be replaced

by the manufacturer or a qualified service technician.

INSTALLATION GUIDELINES:

INSTALLATION 1 - 2 - 3

STANDARD FEATURES

All NorthWind units are designed with “corner post” construction. This permits convenient access to most components

by removal of the right side panel(s) (viewed from the front). A separate electrical control box is located on the lower

back panel. For easy access to the control components, simply remove 4 screws. The power supply cord can be stored

in the cord storage compartment on the back panel. All panels are attached with machine screws into threaded fasteners.

The unit interior consists of three sections: 1) The lower section containing the compressor, condensate removal

system and primary electrical system, 2) The upper front section, containing the evaporator blower, coil, filter and

grilles, 3) The upper rear section, containing the condenser blower, coil filter and grilles.

SERVICEABILITY

COMMERCIAL CABINET

The “corner post” construction provides great strength and virtually no “cabinet flex”. Base pans, corner posts and se-

lect interior panels are 12 gauge galvanized steel on models MAC1211/1811 and 11 gauge on models MAC60 and

MAC90.. The exterior panels are 18 gauge CRS finished with exterior grade, weather resistant, high gloss, polyester

TGIC powder coating. The interior sections are insulated with sound absorbent insulation for quiet and dry operation. A

“Cord Storage Compartment” is located on the back panel near the electric service panel. It provides a convenient place

to protect and store the power supply cord during transport. It also serves to protect and house the fan cycle switch and

high pressure switch reset button on models MAC1211/1811.

THERMOSTATIC EXPANSION VALVE/CAPILLARY TUBE

NorthWind units are equipped with either a thermostatic expansion valve or capillary tube expansion system. Both ac-

curately and efficiently control refrigerant flow.

STANDARD FEATURES continued

CONSTANT PRESSURE EXPANSION VALVE /FREEZE STAT/HOT GAS BYPASS

Each NorthWind unit is provided with a constant pressure expansion valve, freeze stat or hot gas bypass to prevent

frost formation on the evaporator coil. This is most useful when operating in high humidity conditions at low fan

speeds and moderate to lower temperatures.

HIGH PRESSURE SAFETY SWITCH

Each NorthWind unit is equipped with a manual reset high pressure switch

to protect the refrigeration system and compressor. The cut-out pressure for

all models is 425 PSIG. If the system exceeds this pressure, the compressor

will stop. When the system pressure drops to 300 PSIG or less, the reset

button can be pushed to restart the compressor. THE RESET BUTTON IS

LOCATED IN THE CORD STORAGE COMPARTMENT on models

MAC1211/1811. The button is located behind the front service door on

models MAC60 and MAC90. This protects the button from damage during

transport and setup. The high pressure switch capillary line is attached to a

schrader access valve on the liquid line. This allows replacement of a de-

fective switch without recovering the refrigerant.

ADVANCED CONDENSATE REMOVAL SYSTEM

All 1, 1½, and 3 ton units are supplied with the Advanced Condensate Removal System. This

system includes a 5 gallon tank and a high lift condensate pump. The user can choose be-

tween the tank or pump with no wiring or electrical changes. Simply attach a short piece of

1/2 inch o.d. tubing (included with unit) from the evaporator drain pan outlet fitting and in-

sert the other end into the inlet opening on the condensate pump. This system is located be-

hind the door on the lower front panel of the unit. If the pump is used, the pump discharge

line must run to a drain. If the tank is used, the water level control system shuts off the com-

pressor and turns on the red “condensate alert” light when about 5/8 full.

The unit’s evaporator blower will continue operation at its selected mode. To resume cooling operation, the tank must be

emptied. An adjustment screw, located behind the tank, can vary the cut-off switch. If a lighter weight (less water) is de-

sired, turn the adjusting screw clockwise. Do not exceed 1 full turn counterclockwise.

VIEW LOOKING THROUGH DOOR

WITH TANK REMOVED

Evaporator pan outlet

1/2 inch o.d.

Condensate pump

water inlet

The water level microswitch turns off the

compressor and condenser blower when the

tank needs to be emptied. As condensate col-

lects in the tank, it becomes heavier. When

the spring pressure is exceeded by the weight

of the tank, the adjusting screw lowers the

lever on the switch, closing the circuit to the “condensate alert” light

and opening the circuit to the compressor and condenser blower. This

switch operates on 24 volts.

WATER LEVEL MICROSWITCH

Water level adjustment screw and locknut

Microswitch mounted in unit

Spring and tray attachment

CONDENSATE PUMP

Every NorthWind unit is provided with a condensate pump. The pump has a 20

foot lift, an internal check valve, and a safety float switch. The pump is securely

mounted to the base pan with all primary wiring and piping factory finished. A con-

densate discharge line is required when the pump is being used. When not used, the

pump is simply in standby mode.

Condensate pump in unit models

MAC1211/1811

CONDENSATE ALERT LIGHT, RED

Every NorthWind unit is equipped with a red Condensate Alert light. The light is lit when one of two conditions ex-

ists: 1) The condensate tank is full. 2) The condensate cannot be pumped out of the condensate pump. 3) This requires

pushing the reset button in the unit’s cord storage compartment (MAC1211/1811) or behind the front access door

(MAC60/90), to restart the unit.

THERMOSTAT

Every NorthWind unit is equipped with an electromechanical thermostat operating on 24 volts. The dial on the unit

control panel is in the off position when turned full counterclockwise. When turned full clockwise, the temperature

setpoint will be approx. 55° F @ ± 4°. The temperature sensing function is through a remote bulb located in front of

the evaporator coil, in the air stream.

POWER READY LIGHT, GREEN

All NorthWind units are equipped with a green “Power Ready” light. When lit, it indicates there is power at the recepta-

cle. Even when the unit is in the “off” position, the light should be lit. If this light is “off”, there is no power available

for the unit to run. Perhaps a fuse or circuit breaker should then be checked.

TIME DELAY RELAY

Each unit is equipped with an adjustable, low voltage time delay relay to protect the compressor from short cycling,

which could cause internal damage. This device is “delay on break” actuated and is located in the electrical box on the

lower back panel of the unit. The adjustment dial on the relay is factory set and should not need any further attention.

EVAPORATOR FAN RELAY/CONTACTOR

The evaporator fan relay controls the 2 speeds of the evaporator motor on models MAC1211/1811. The relay is SPDT

with a 24 volt coil. Models MAC60/90 use a separate contactor for each speed using 24 volt coils.

CONTROL TRANSFORMER

The control transformer supplies 24 volts to the unit’s low voltage control system. It is a foot mounted, 40VA, multi-

tap primary that is energized when the power cord is connected to a “hot” receptacle.

CONDENSATE PUMP TRANSFORMER

Used only on 480 volt 3 phase models, it provides 230 volts to power the unit’s condensate pump.

24 volt

transformer

Compressor

Contactor

Power

Terminal

Block

Panel

Ground

Compressor

Time Delay

Relay

Evaporator

Fan Relay

ELECTRICAL PANELS

MAC1211/1811 panel

MAC6034/9034 panel

Power

Terminal

Block

Phase

Monitor

Condensate

Pump

Transformer

Control

Transformer

Ground Lug

Compressor

Contactor

Evap Hi-Speed

Contactor

Evap Lo-Speed

Contactor

Cond Fan

Contactor

COMPRESSOR CONTACTOR

The compressor contactor supplies power to the compressor and the condenser blower when the thermostat calls for cooling.

It has a 24 volt coil, with the amp rating and number of poles required for the specific model.

TERMINAL BLOCK

The terminal block has 3 terminals that provide a convenient wiring point for the power supply cord internal wiring and pri-

mary grounding.

AUTOMATIC CONDENSER FAN CYCLE SWITCH

Every NorthWind unit is equipped with an automatic condenser fan cycle switch. At 260 PSIG

the condenser blower switches on, automatically. When the load decreases and the pressure in

the liquid line drops to 160 PSIG, the condenser blower turns off, automatically. The switch is

mounted on a schrader access valve, and it can be replaced without recovering the refrigerant.

EVAPORATOR FAN CYCLE SWITCH

All of NorthWind’s units are equipped with an evaporator fan cycle switch. Located in the cord storage box (models

MAC1211/1811) and behind the front access door (model MAC60/MAC90, when switched to “cycle” function, the

evaporator blower turns on and off with the compressor. When switched to the “constant” function, the evaporator

blower runs continuously. The constant function may help prevent air stratification as well as clean the air with the

electrostatic filters.

EVAPORATOR FAN SPEED SWITCH

Each NorthWind unit is supplied with a 2-speed evaporator fan switch. Located on the unit’s control

panel, the “High” speed selection runs the blower at maximum speed. The “Low” speed selection runs

the blower at 20% less than high speed. The fan switch operates on 24 volts.

AIR FILTERS

All NorthWind units include an electrostatic air filter in the evaporator and condenser air handling systems. An electro-

static filter imparts a small static charge to dirt particles passing through it. The media then captures this dirt much

more efficiently than standard foam or aluminum mesh filters. Made of polymer coated polypropylene, the filters can

be washed with mild detergent or backwashed with a garden hose.

ON-OFF SWITCH

The “ ON-OFF” switch provides a way to stop all electrical functions on the unit except the

“Power Ready” light. If the unit is plugged in and there is power at the receptacle, the green

light will be lit even if the power switch is in the “OFF” position. This lets the user know

when the receptacle is live.

EVAPORATOR & CONDENSER BLOWER MOTOR ASSEMBLIES

Each 1 and 1½ ton unit is equipped with a new technology external rotor,

forward curved, squirrel cage blower for the evaporator and condenser sec-

tions. The external rotor motor is totally enclosed, PSC, thermally protected,

2-speed, with sealed ball bearings, and dynamically balanced in 2 planes for

reduced noise/vibration levels. The blower wheel is bolted to the rotating

stator section, eliminating set screws. The double inlet design puts the motor

section in the center of the wheel, leaving both air inlets free of any motor

obstruction and in the air stream for cool efficient operation, unlike standard

direct drive blowers. No oiling or mechanical servicing is required.

MAC60/90 models utilize belt drive blowers/motors which provide the increased air flow at very moderate noise

levels. All motor pulleys are keyed to the shaft and secured with tapered style bushings. Blower pulleys are secured

with tapered bushings, eliminating the need for set screws.

The motors are solidly bolted to the motor mounting plate. Adjustment and belt tension are easily set by raising or

lowering the plate and tightening the adjustment bolts.

Motor mounting plate

Adjustment rods

Belt adjustment/replacement is easy. Just

loosen the nuts on the top and bottom of

the motor plate, roll off the old belt...roll

on the new one… tighten the bolts to ap-

ply tension to the belt and motor plate.

Lock nuts on top and bottom

of motor mounting plate

MAC60 condenser blower

MAC60 evaporator blower

Inside view of MAC90

showing the arrangement of

internal components.

SERVICE CORD

Every NorthWind unit has a 10 foot long electrical service cord. On all required service cords, an electric protection

device (LCDI/AFCI)* is included. This complies with the UL requirements issued August 1, 2004. There are no re-

quirements for these devices on 3 phase units.

UNIT/MODEL PLUG CONFIGURATION RECEPTACLE

115 VOLT

MAC1211,

MWC1211

NEMA-5-15R

115 VOLT

MAC1811

MWC1811

NEMA 5-20R

208/230/1

MAC2412

MWC2412, 3612

NEMA 6-20R

208/230/1

MAC3612

MWC6012

NEMA 6-30R

208/230/1

MAC6012

NEMA 6-50R

208/230/3

MAC3632

MWC3632

NEMA L15-20R

208/230/3

MAC6032

MWC6032

NEMA L15-30R

460/480/3

MAC3634

MWC3634

NEMA L16-20R

460/480/3

MAC6034

MWC6034

NEMA L16-30R

15A-125 VOLT

NEMA 5-15P

20A-125 VOLT

NEMA 5-20P

20A-250 VOLT

NEMA 6-20P

30A-250 VOLT

NEMA 6-30P

50A-250 VOLT

NEMA 6-50P

20A-250 VOLT

NEMA L15-20P

30A-250 VOLT

NEMA L15-30P

20A-460 VOLT

NEMA L16-20P

30A-460 VOLT

NEMA L-16-30P

*LCDI (Leakage Current Detection & Interruption) AFCI (Arc Fault Circuit Interrupter)

TREATED EVAPORATOR AND CONDENSER COILS

When environmental conditions are harsh and airborne contaminants are a problem, a degrading of the coil surfaces could

occur. To help mediate this problem, coils could be treated with an optional acrylic or heresite coating. Please contact your

distributor for suggestions and application assistance.

CONDENSER DUCT

If your unit is operating in an office, server/computer room or other finished space, condenser duct may be used to handle

the hot condenser air or condenser make-up air. 12 inch round duct is used on the discharge of the MAC1211, 1811, and

3612/32. The MAC6012/32/34 use 1, 16 inch round duct. The MAC9032/34 use 2, 16 inch round duct.

CEILING PANEL/DUCT KIT ASSEMBLY

An optional ceiling discharge kit (CDK) may be used to discharge condenser warm air into a drop ceiling space. The CDK-

12 consists of a 2' x 2' lay-in ceiling panel, 8 feet of flexible duct, and a 12 inch diameter duct flange that attaches to the top

of the unit over the air discharge opening. The CDK-16 has similar components for larger, 16 inch diameter duct. Installation

can be accomplished in 2 steps:

1) Place the 2' x 2' drop-in ceiling panel in the drop ceiling above the unit.

2) Attach the duct flange to the unit with the machine screws supplied with the kit.

Installation is complete.

Non-ventilated ceiling must be large enough to handle the warm air generated by the unit. Best case is to vent into only

“VENTED” ceiling areas.

Check your local codes for any special “drop ceiling space” requirements. Comply with all ordinances.

OPTIONAL FEATURES

COLD AIR DISCHARGE NOZZLE KIT

Optional nozzles are used to direct the cold evaporator air to specific areas or spots. Thus the term “spot” cooling was

coined. Spot cooling is generally used in commercial and industrial applications such as production lines to cool people or

processes, or to cool equipment that generates heat such as computers or telecommunication products. You may have seen

them on the sidelines of sporting events to cool the athletes. The nozzles are made of Virgin white PVC 100, ribbon locked,

bendable, self-supporting, resistant to corrosion/ rust, abrasion, solvents, acid and chemicals. The black tips (finishing rings)

are made of soft plastic providing an attractive finish and protection from sharp edges. The nozzle construction is firm, and

when aimed at a spot, the nozzle will maintain that position until changed.

The NZ-5 is used on the MAC1211, 1811. It consists of 2, 5-inch nozzles with a compressed length of 16 inches and ap-

proximate extended length of 24 inches.

The NZ-6 is used on the MAC3612. It consists of 2, 6-inch nozzles with a compressed length of 16 inches and approximate

extended length of 24 inches.

The NZ-8 is used on the MAC6012, 32 and 34. It consists of 2, 8-inch nozzles with a compressed length of 16 inches and

approximate extended length of 24 inches.

The NZ-10 is used on the MAC9032/34. It consists of 2, 10-inch nozzles with a compressed length of 16 inches and ap-

proximate extended length of 24 inches.

DUCT FLANGE

An optional duct flange can be attached to the condenser discharge (hot) air opening on the top of the unit. Round duct can

then be attached to it. The CDF-12 (Condenser Duct Flange) is 12 inches in diameter and fits models MAC12 and 18. The

CDF-16 is 16 inches in diameter and is included (installed) on models MAC60 and 90.

CONDENSER AIR PLENUM

The CAP, Condenser Air Plenum, is used to eliminate negative air pressure in the conditioned space caused by exhausting

the condenser air. The plenum attaches to the condenser inlet air opening on the side of the unit. They connect by removing

the grille assembly and dropping in the plenum in its place. 12 inch round duct can then be routed from an exterior source

and attached to the plenum flange. Additional duct may be attached to the condenser discharge flange for a totally ducted

condenser section. Condenser air plenums can substantially reduce air noise and increase options for solving difficult and

unusual cooling applications. All NorthWind units use a dedicated, automatic, 2 speed condenser blower controlled by the

“load” or pressure in the high side of the refrigerant system.

Another important topic to consider is the amount of duct that can be attached to a unit. Adding duct adds resistance to air-

flow. Too much duct will prevent the unit from operating properly. For proper application, “equivalent feet” must be calcu-

lated. To calculate equivalent feet, add the number of feet of duct on the inlet side of the blower (inlet air plenum) plus the

number of feet on the discharge air side (duct connected to discharge air flange).

Then, for every 90° elbow in the ducting, add 6 feet to the calculation. Here is an example of an equivalent feet calculation:

Number of feet of duct attached to discharge flange 15

Number of feet of duct attached to inlet plenum 20

Number of 90° elbows in discharge run, 1 (= 6 feet) 6

Number of 90° elbows in inlet run, 2 (= 12 feet) 12

Total equivalent feet 53

The following quick reference chart illustrates maximum equivalent feet and maximum E.S.P. (External Static Pressure) al-

lowed for the condenser section of NorthWind units.

Condenser

Plenum Model Round Duct

Size, Inches Maximum

Equivalent Feet Maximum

E.S.P.

CAP12 12 50 .50

CAP18 12 50 .50

CAP36 12 80 .60

CAP60 2-12 110 .70

CAP90 2, 16 120 .80

EVAPORATOR DUCT ADAPTER

The evaporator duct adapter is used to transition the evaporator discharge opening to round duct. The standard grille

can be lifted out of the opening and the adapter can be dropped in its place. By attaching duct to the adapter, cold air

can be delivered to a location some distance from the unit.

Then, for every 90° elbow in the ducting, add 6 feet to the calculation. Here is an example of an equivalent feet calcu-

lation:

Number of feet of duct attached to discharge flange 15

Number of feet of duct attached to inlet plenum 20

Number of 90° elbows in discharge run, 1 (= 6 feet) 6

Number of 90° elbows in inlet run, 2 (= 12 feet) 12

Total equivalent feet 53

Evaporator duct adapters can substantially reduce air noise and increase the number of options used for solving diffi-

cult and unusual cooling applications. All NorthWind units use a dedicated, automatic, 2-speed evaporator blower

controlled by the fan speed switch mounted on the unit control panel. Another important topic to consider is the

amount of duct that can be attached to a unit. Adding duct adds resistance to airflow. Too much duct will prevent the

unit from operating properly. For proper application, “equivalent feet” must be calculated. To calculate equivalent

feet, add the number of feet of duct on the inlet side of the blower (inlet air plenum) plus the number of feet on the dis-

charge air side (duct connected to evaporator duct adapter).

This quick reference chart illus-

trates maximum equivalent feet and

maximum E.S.P. (External Static

Pressure) allowed for the evaporator

section of NorthWind units.

Evaporator Duct

Adapter Model Round Duct

Size, Inches Maximum

Equivalent Feet Maximum

E.S.P.

EDA12, 18 8 40 .50

EDA36 16 80 .50

EDA60 16 110 .70

EDA90 18 120 .90

EVAPORATOR AIR PLENUM

Evaporator Air Plenums are used to connect round duct to the evaporator inlet air of the unit. The plenum attaches to the unit

by removing the grille and dropping in the plenum in its place on all models.

Then, for every 90° elbow in the ducting, add 6 feet to the calculation. Here is an example of an equivalent feet calculation:

Number of feet of duct attached to discharge flange 15

Number of feet of duct attached to inlet plenum 20

Number of 90° elbows in discharge run, 1 (= 6 feet) 6

Number of 90° elbows in inlet run, 2 (= 12 feet) 12

Total equivalent feet 53

Evaporator air plenums can substantially reduce air noise and increase the number of options used for solving difficult and

unusual cooling applications. All NorthWind units use a dedicated, automatic, 2 speed evaporator blower controlled by the

fan speed switch mounted on the unit control panel. Another important topic to consider is the amount of duct that can be

attached to a unit. Adding duct adds resistance to airflow. Too much duct will prevent the unit from operating efficiently.

For proper application, “equivalent feet” must be calculated. To calculate equivalent feet, add the number of feet of duct on

the inlet side of the blower (inlet air plenum) plus the number of feet on the discharge air side (duct connected to evaporator

duct adapter).

The quick reference chart illustrates

maximum equivalent feet and maxi-

mum E.S.P. (External Static Pres-

sure) allowed for the evaporator sec-

tion of NorthWind units.

Evaporator

Plenum Model Round Duct

Size, Inches Maximum

Equivalent Feet Maximum

E.S.P.

EAP12 12 30 .40

EAP18 12 40 .50

EAP36 16 80 .50

EAP60 16 110 .70

EAP90 18 120 .90

APPLICATIONS

ROOM AIR CONDITIONER

NorthWind units can be used as room air conditioners to cool a room or confined space. This application requires using a

CAP (Condenser Air Plenum) and a CDF (Condenser Duct Flange) to duct condenser air into the unit and duct condenser

hot air out of the unit. If this ducting is not used, the space temperature will increase.

SPOT COOLER

NorthWind units may be used in open areas to cool specific “spots” through the evaporator grille, optional nozzles or duct

adapter. Spot cooling can be an economical and convenient method to air condition where cooling the entire space is not

practical, such as factory floors, warehouses, gyms, stadiums and similar large areas.

REMOTE COOLER

By using the optional EAP (Evaporator Air Plenum) and EDA (Evaporator Duct Adapter) it is possible to cool a space

remotely. The Plenum and Duct Adapter permit ducting of the evaporator air. In drop ceiling applications the unit could

be located in one room while ducting the supply and return air to another room. The “equivalent feet” guidelines must be

observed.

AREA COOLER

When a unit is installed in an area that is not totally enclosed, the hot condenser air may be ducted out, allowing the

evaporator air to cool the space. Consideration must always be given to the negative pressure created by the condenser air

exhaust and its effect on space temperature.

FAN ONLY OPERATION

When fan only operation is desired, turn the thermostat dial to desired comfort level and switch fan cycle switch to

“constant” position. The fan cycle switch is located in the cord storage compartment on the unit’s back panel. With the

switch in “constant” position, the evaporator fan will operate even when the call for cooling is satisfied. Select desired

fan speed from the control panel. To cycle (turn off) the evaporator fan with the compressor, switch the fan cycle

switch to “cycle”.

COOLING CYCLE

To operate the unit for cooling, plug the electric cord into a proper power supply. The green “power ready “ light

should be lit. If the green light is not illuminated, there is probably no power at the outlet. Turn the temperature dial to

the right (clockwise) to turn the unit on, selecting the desired comfort number. The unit will run until the call for cool-

ing is satisfied. The temperature sensing bulb is located behind the evaporator filter and in front of the evaporator coil.

This is the best position for sensing the room temperature. With the unit running, if the dial is turned to the left

(counterclockwise) to turn the unit off, and then immediately turned to the right (clockwise), to turn it back on, the unit

will not start. The time delay will not allow the unit to run until the delay period ends, usually 4 to 5 minutes. This is

normal and protects the compressor from damage. If there is a power failure, the unit will resume operation when

power is restored. No re-starting is required. Operation will be as though there was no power failure at all. No batteries

of any kind are required for the thermostat or any operating function of the unit.

REPLACEMENT PART PROCEDURES

THERMOSTAT

1. Disconnect unit from power/unplug power cord.

2. Remove evaporator inlet air grille on the front panel of unit.

3. Remove screws and clips that secure the thermostat sensing bulb.

4. Remove the unit’s top panel attaching screws. Lift panel 6 to 8 inches to reveal components on control panel.

5. Pull sensing bulb and tubing up and out from the evaporator coil area.

6. Mark and remove wires from ON/OFF Switch.

7. Mark and remove wires from Evaporator Fan Switch

8. Mark and remove wires from Condensate Alert Light and Power Ready Light.

9. With a small slotted screwdriver, remove thermostat dial set screw from shaft. Note: Set screw is always tightened

on FLAT section of shaft. Remove dial.

10. Remove switches and lights from control panel.

11. Remove instrument panel overlay by prying up the edges first, then pulling it completely off.

12. Remove 2 thermostat attaching screws; then remove thermostat.

13. Install new thermostat and attaching screws. Apply new overlay.

14. Snap in Fan Switch, ON/OFF Switch, and Green and Red light through new overlay.

15. Reconnect marked wires, guide thermostat bulb to mounting location and attach with clips.

16. Reinstall top panel & attaching screws; replace evaporator grille assembly.

EVAPORATOR BLOWER

CONDENSER BLOWER

1. Disconnect unit from power/unplug power cord.

2. Remove screws to top, right & left side panel, and remove.

3. Remove evaporator duct shroud.

4. Cut, mark and strip electric wires from blower motor for re-connection later.

5. Position top panel to permit blower removal.

6. Remove 1/4 inch countersunk screws and nuts from blower mounting brackets.

7. Remove blower mounting brackets from inoperative blower to new blower.

8. Install new blower in unit attaching 1/4 countersunk screws & nuts.

9. Connect new blower wires to stripped and marked wires.

10. After wiring, test to make sure new blower operates; then reassemble in reverse order.

BELT DRIVE

1. Remove screws on top panel, remove right and left side panels, duct shroud and blower screen.

2. Loosen belt tension, remove belt, blower pulley, adjusting rods, blower motor and plate.

3. Remove 1/4 in nuts & bolts that attach blower cage to basepan and vertical partition.

4. Remove blower and cage assembly from unit through right side, lifting the cage over the unit wiring.

5. Remove nuts & bolts that attach blower to cage assembly; re-install new blower.

6. Reassemble in reverse order, and test for proper operation; reattach side panels & top.

1. Disconnect unit from power/unplug power cord.

2. Remove screws to top, right & left side panel, and remove.

3. Remove condenser duct shroud.

4. Cut, mark and strip electric wires from blower motor for re-connection later.

5. Position top panel to permit blower removal.

6. Remove 1/4 inch countersunk screws and nuts from blower mounting brackets.

7. Remove blower mounting brackets from inoperative blower to new blower.

8. Install new blower in unit, attaching 1/4 countersunk screws & nuts.

9. Connect new blower wires to stripped and marked wires.

10. After wiring, test to make sure new blower operates; then reassemble in reverse order.

BELT DRIVE

1. Follow same procedure for evaporator blower except there is no blower screen to remove.

DIRECT DRIVE

POWER READY or CONDENSATE ALERT LIGHT

CONDENSATE PUMP

EVAPORATOR FAN SWITCH and ON/OFF SWITCH

HIGH PRESSURE SWITCH

1. Disconnect unit from power/unplug power cord.

2. Remove attaching screws that secure the top panel.

3. Lift the top front panel about 6 inches to reveal the 2 wires that attach the light. The copper sensing tube for the

thermostat will provide some resistance. This is normal. However, do not kink the tubing.

4. Cut the 2 wires, pull the tinnerman clip away from the panel, and push the light out the front of the panel.

5. Push the new light through the panel and secure with the tinnerman clip.

6. Strip the insulation on the 2 cut wires in the unit. Attach one light wire to one of the just stripped wires and the

other light wire to the other just stripped wire. Secure with a wire nut or butt connector, and tape the nut and wire

together for extra strength.

7. Reinstall top panel and screws.

1. Disconnect power supply /remove plug from receptacle.

2. Remove right side panel.

3. Loosen nuts/bolts on pump mounting brackets.

4. Remove pump electrical cover (1 Phillips screw).

5. Remove & mark wires on low voltage and line voltage float switches; check terminals for tightness & suitability.

6. Replace condensate pump, reattach wires, replace cover & screw, reinstall attaching bolts, reinstall side panel.

1. Disconnect unit from power/unplug power cord.

2. Remove attaching screws that secure the top panel.

3. Lift the top front panel about 6 inches to reveal the switch and the 2 wires attached to it. The copper

sensing tube will provide some resistance. This is normal. However, do not kink the tubing.

Note: Mark the wire located on the center terminal and the wire on the outer terminal. Remove the wires by

pulling from the terminal.

4. With thumb and forefinger, squeeze the spring clips together that are on the LONG side of the switch and

push the switch out from the back, through the front panel.

5. Reinstall the new switch by pushing it through the panel from the front until it snaps into place.

6. Reattach wires, taking note of which wire was on the center terminal and which wire was on the outer terminal.

7. Reinstall top panel and attaching nuts.

1. Disconnect unit from power/unplug power cord.

2. Remove attaching screws from right side panel; remove panel.

3. Remove 4 screws from electrical access panel on lower back panel.

4. Remove nuts/bolts attaching the high pressure switch to the panel.

5. Mark location of two blue wires; remove from terminals.

6. Follow the tubing from the high pressure switch to the flare nut which attaches it to the

schrader access valve.

7. Remove flare nut from access valve. A small, DeMinimus release of refrigerant may occur when separating the

components. This is normal.

8. Pull the tubing, nut and wires through the panels, removing the switch assembly.

9. Reinstall, reversing the procedure.

High Pressure Switch

CONDENSER FAN CYCLE CONTROL

PANEL MOUNTED RELAYS, CONTACTORS, TIME DELAY TRANSFORMER

1. Disconnect unit from power; unplug power cord.

2. Remove right side panel of unit.

3. Remove and mark 2 wires on terminals of cycle switch to assure correct reconnection.

4. Using a 9/16 flare tube wrench, remove switch from schrader access valve. A small, DeMinimus

release of refrigerant may occur when components are separated. This is normal.

5. Install new fan cycle switch and use reverse order to finish process. Condenser Fan

Cycle Switch

1. Disconnect power to unit, unplug power cord.

2. Remove 4 screws on the electrical cover located on the unit’s lower back panel.

3. Select control to be replaced, carefully marking wires for reattaching to new control.

4. Remove control from panel; reinstall new control.

5. Reconnect wires; reinstall panel cover.

Electrical Panel

INSPECTION/REPAIR OF ELECTRICAL SYSTEM

1. Inspection of thermostat: Check for continuity across terminals 1 and 2, (C-12, C-21) and terminals 4 and 5 on C-17, when

calling for full cooling (dial full clockwise) above 65°F. If continuity is broken across the terminals, replace the thermostat.

2. Inspection of fan speed switch:

There should be continuity across the above terminals. If none, replace the switch.

3. Inspection of tank full switch: Depress the microswitch lever to check for continuity. If there is no continuity between

common and normally open terminals, replace the switch.

4. Inspection of high pressure switch: Check for continuity across terminals 1 and 2 of the high pressure switch. At normal

pressure when the unit is not operating, there is continuity across the two terminals. If continuity is interrupted across the

terminals, replace the high pressure switch.

5. Inspection of compressor motor: Measure the resistance across the terminals of the compressor motor.

Resistance between C-R at 70°F approximately 0.65 OHMS ± 10%

Resistance between C-S at 70°F approximately 4.50 OHMS ± 10%

Replace compressor when the resistance is not at these stated values.

6. Inspection of compressor overload : Check for continuity across overload’s two terminals. At normal room temperatures,

there is continuity across the two terminals. If no continuity exists, replace the overload.

7. Inspection of compressor and fan motor capacitors: Before and after the test, always short across the two terminals to

discharge electric charge. Set the ohmmeter to 100 OHMS range and place its two probes against the two terminals of the

capacitor. At first, the ohmmeter should indicate zero OHMS, then the meter reading should gradually approach infinity. If

the ohmmeter shows infinity from the outset or the meter reading does not move from zero OHMS, replace the capacitor.

SWITCH POSITION CONDUCTING TERMINALS

High Speed Center & Left Terminal

Low Speed Center & Right Terminal

Back View of Switch

CAUTION: DISCONNECT POWER TO UNIT PRIOR TO INSPECTION

TROUBLESHOOTING GUIDE

The following procedures are recommended when correcting the indicated problems. Routine clean-

ing and maintenance can be performed by anyone. Service and repair should be performed only by

a qualified refrigeration service person.

PROBLEM: THE ENTIRE UNIT DOES NOT RUN. Green light not lit.

1. CAUSE: POWER INTERRUPTION

REMEDY: Check external power supply. Look for blown fuse or open circuit breaker. Replace fuse/reset

breaker. Check to make sure no other power consuming equipment is on the same circuit as the unit.

PROBLEM: THE ENTIRE UNIT DOES NOT RUN. Green light lit.

1. CAUSE: THERMOSTAT INOPERABLE

REMEDY: Setting may be too high to call for cooling. Lower set point by turning temperature dial clockwise.

Tighten or replace any loose or broken wire on thermostat. Replace thermostat if defective.

2. CAUSE: ELECTRICAL PANEL: a) contactor coil defective, contacts stuck open, burned or dirty.

b) loose wires.

REMEDY: Correct as follows: (a) Tighten /replace loose wire terminals. (b) Replace contactor

PROBLEM: EVAPORATOR FAN RUNS BUT COMPRESSOR AND CONDENSER FAN DO NOT

START.

1. CAUSE: Low Voltage

REMEDY: Check power supply for voltage outside the range of 106-126 on 115 volt models and 187-253 volts

on the 208/230 volt units.

2. CAUSE: Thermostat

REMEDY: Check for loose wires on the thermostat. Tighten wires, wait for time delay (3-5 minutes), then

restart unit.

3. CAUSE: High Pressure Switch opened circuit.

REMEDY: Push high pressure switch button (located in cord storage compartment) to reset switch. Make sure

condenser coil is not obstructed; there should be 8 inches of clearance from condenser inlet air

opening and wall. Make sure condenser filter is clean and open. Replace HP switch if defective or

bypass to test. Make sure electrical connections are tight and secure.

4. CAUSE: Compressor contactor open or burned. REMEDY: Replace if necessary.

5. CAUSE: Refrigerant Leak; no freon. REMEDY: Locate leak and repair. Evacuate unit and recharge.

6. CAUSE: Loose or defective wires. REMEDY: Tug on wires to see if they pull away from the connections,

including compressor. Repair/Replace any wires & terminals as required.

7. CAUSE: Open or shorted run capacitor. REMEDY: Repair or replace.

8. CAUSE: Defective “condensate alert” cut-out switch. REMEDY: Check and replace.

9. CAUSE: Condensate tank could be full, but red alert light could be defective. REMEDY: Replace light.

10. CAUSE: Defective compressor. REMEDY: Check for shorts, opens and grounds. Remove & replace

compressor. Recharge. Test run.

PROBLEM: COMPRESSOR STARTS & RUNS, BUT EVAPORATOR FAN DOES NOT RUN.

1. CAUSE: Loose wires on fan speed switch or fan cycle switch. REMEDY: Check for loose wires,

repair/replace as required.

2. CAUSE: Defective fan speed switch. REMEDY: Remove/replace fan switch.

3. CAUSE: Defective fan cycle/constant switch in cord storage compartment. REMEDY: Remove & repair

switch.

4. CAUSE: Shorted or open fan motor capacitor. REMEDY: Remove/replace capacitor.

5. CAUSE: Open fan motor coil (winding). REMEDY: Remove/replace evaporator blower.

6. CAUSE: Defective fan relay, burned contact or defective pull-in coil. REMEDY: Remove/replace relay.

PROBLEM: INSUFFICIENT COOLING

1. CAUSE: Insufficient air flow through evaporator coil due to:

A. Dirty air filter B. Dirty evaporator coil

C. Obstructed evaporator inlet air

REMEDY: A. Remove filter grille assembly, wash filter or clean with vacuum.

B. Remove obstruction.

2. CAUSE: IMPROPER SIZING OF UNIT. REMEDY: Make sure unit is properly sized for load (application).

Add supplemental unit(s) as required.

PROBLEM: NOISY OPERATION

1.CAUSE: Copper tubing vibrating. REMEDY: Adjust by bending copper tubing slightly to a new, firm

position. Segregate tubes touching cabinet or each other.

2. CAUSE: Loose cabinet or internal component. REMEDY: Check, tighten loose screws.

3. CAUSE: Unit vibrating out of level. REMEDY: Re-position so it is level with the floor.

4. CAUSE: Object dropped into evaporator or condenser blower. REMEDY: Turn unit off, inspect blower

housings for foreign objects; remove and restart unit.

5. CAUSE: Loose blower mounting bolts. REMEDY: Tighten bolts, restart blower.

6. CAUSE: Defective external rotor motor. REMEDY: Remove/replace blower assembly.

7. CAUSE: Loose or misaligned blower/motor pulley/belts on belt drive units.

8. CAUSE: Loose set screws on blower pulley or blower motor pulley. REMEDY: Inspect,

repair/tighten/replace set screws to eliminate noise.

9. CAUSE: Defective/worn motor mount rings. REMEDY: Repair/replace motor mount rings.

PROBLEM: WATER LEAKING FROM UNIT

1. CAUSE: Leaky drain pan. REMEDY: Locate and repair leak with proper sealant.

2. CAUSE: Loose drain hose connection or hole in hose. REMEDY: Locate hole; replace hose if necessary. Tighten

hose clamp.

3. CAUSE: Did not replace tank after emptying. REMEDY: Replace tank to collect water properly.

4. CAUSE Tank improperly installed. REMEDY: Make sure water collection hole tank is in the UP position.

5. CAUSE: Defective condensate pump or excessive lift on pump. REMEDY: If pump lift exceeds 20 feet, a higher

lift pump will be necessary. Make sure check valve is operative, safety float is not energized, and

discharge line is not plugged or crimped. Change pump if necessary. Pump will operate against 20 feet of

water head pressure. If a combination of vertical height and horizontal drain line exceeds 20 feet of water

pressure drop, problems will occur.

PREVENTIVE MAINTENANCE GUIDE

All NorthWind units are designed to last and give maximum performance/reliability with minimum maintenance. To

extend the life of the unit, a few simple procedures must be performed.

1. BLOWER MOTORS

The external rotor motor and blower wheel is a balanced/bolted assembly requiring no maintenance. It is used in the

MAC1211, MAC1811.

Belt drive motors and blowers use pulley set screws and should be checked for tightness whenever the side panel is

removed for cleaning/maintenance. Belts should be inspected twice a year. All bearings are sealed and permanently

lubricated.

2. FILTERS

Every NorthWind unit is equipped with enhanced particle capture electrostatic filters (condenser and evaporator). Anti-

microbial protection is imbedded in the fiber and cannot be washed out. They are impervious to harsh conditions, UV

protected, nonreactive to chemicals/corrosive conditions and nonporous (will not absorb from the environment). How-

ever, they must be kept clean. Clogged filters reduce airflow and the efficiency of the system. Some environments require

filter cleaning every 2 weeks. Others, every 6 weeks. Clean as often as your conditions require.

The evaporator filter is located behind the evaporator grille, in the front panel. The filter and grille can be easily lifted out

of the unit. Once out of the unit, the filter can be sprayed with detergent and hosed off with water. Just shake off the ex-

cessive water and reinstall. The condenser filter is located behind the condenser grille on the left side of the unit. Clean

and reinstall using the same method as with the evaporator filter.

3. CONDENSATE PUMP

Follow these steps when servicing the condensate pump:

1. Disconnect power before servicing pump or any other component.

2. Make sure the floats move up and down freely and smoothly. Listen for the clicks of the switches.

3. Remove tank cover, clean volute and bottom of tank. Warm water, detergent or humidifier cleaner can be used to

remove any mineral deposits.

4. Make sure check valve moves freely and is free from any obstruction, particle or mineral buildup.

5. Inspect drain tubing for obstruction, dirt or kinks that could impede water flow. Clean and correct as necessary.

END OF SEASON STORAGE

1. Remove all water from the condensate tank.

2. Clean evaporator and condenser filters.

3. Remove any water from condensate pump sump and tank.

4. Turn the thermostat dial full counterclockwise (warmest position). Turn the unit on and run

2 hours in constant fan mode to completely dry out the filters and inside components.

5. Roll up the power cord and store in the cord storage box.

6. Store in a dry location.

7. Pack in original carton for extra protection.

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Northwind MAC1211 Engineering, Installation And Service Manual

Brand: Northwind

Model: MAC1211

Category: Split-system air conditioners

Type: Engineering, Installation And Service Manual

This manual is also suitable for

MAC9034

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Northwind MAC1211 Engineering, Installation And Service Manual

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Northwind MAC1211 Engineering, Installation And Service Manual

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