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B.

START UP AND MAKE ADJUSTMENTS

CAUTION:

Complete the required procedures given in

the Pre-Start- Up section before starting the unit. Do not
jumper any safety devices when operating the unit. Do
not operate the compressor when the outdoor temperature
is below 40°F (unless accessory low-ambient kit is
installed). Do not rapid-cycle the compressor. Allow 5
minutes between “on” cycles to prevent compressor
damage.

C.

CHECKING COOLING CONTROL OPERATION

Start and check the unit for proper cooling control operation as
follows:

1. Place room thermostat SYSTEM switch in OFF position.

Observe that blower motor starts when FAN switch is
placed in ON position and shuts down when FAN switch is
placed in AUTO position.

2. Place SYSTEM switch in COOL position and FAN switch

in AUTO position. Set cooling control below room tem-
perature. Observe that compressor, outdoor fan, and indoor
blower motors start. Observe that compressor and outdoor
fan shut down when control setting is satisfied and that
indoor blower shuts down after fan time delay expires.

3. When using an auto-changeover room thermostat, place

both SYSTEM and FAN switches in AUTO positions.
Observe that unit operates in heating mode when tempera-
ture control is set to “call for heating” (above room
temperature) and operates in cooling mode when tempera-
ture control is set to “call for cooling” (below room
temperature).

D.

CHECKING HEATING CONTROL OPERATION

Start and check the unit for proper cooling control operation as
follows:

1. Place room thermostat SYSTEM switch in OFF position.

Observe that blower motor starts when FAN switch is
placed in ON position and shuts down when FAN switch is
placed in AUTO position.

2. Place SYSTEM switch in HEAT position and FAN switch

in AUTO position. Set cooling control above room tem-
perature. Observe that compressor, outdoor fan, and indoor
blower motors start. Observe that compressor and outdoor
fan shut down when control setting is satisfied and that
indoor blower shuts down after fan time delay expires.

3. When using an auto-changeover room thermostat, place

both SYSTEM and FAN switches in AUTO positions.
Observe that unit operates in heating mode when tempera-
ture control is set to “call for heating” (above room
temperature).

4. If system is equipped with supplemental or emergency heat

(resistance heaters), observe that when thermostat is placed
in EMERGENCY HEAT mode and temperature control is
set above room temperature that heaters and indoor blower
come on. Observe that heaters shut off when control setting
is satisfied and that the indoor blower shuts off after fan
time delay expires.

E.

CHECKING

AND

ADJUSTING

REFRIGERANT

CHARGE

The refrigerant system is fully charged with R-22 refrigerant,
tested, and factory-sealed.

NOTE:

Adjustment of the refrigerant charge is not required

unless the unit is suspected of not having the proper R-22 charge.
A superheat charging chart is attached to the outside of the
compressor access panel. The chart includes the required suction
line temperature at given suction line pressures and outdoor
ambient temperatures (See Table 13A-H and Fig. 30).
An accurate superheat, thermocouple- or thermistor-type ther-
mometer, a sling psychrometer, and a gauge manifold are required
when using the superheat charging method for evaluating the unit
charge. Do not use mercury or small dial-type thermometers
because they are not adequate for this type of measurement.

Fig. 24—High-Voltage Connections

C99057

GROUND LUG

(IN SLPICE BOX)

BLU

YEL

BLK

GROUND

LEAD

SINGLE-PHASE
CONNECTIONS
TO DISCONNECT
PER NEC

3-PHASE
CONNECTIONS

LEGEND
NEC  – National Electrical Code

Field Wiring
Splice Connections

NOTE:  Use copper wire only.

L1

L3

L2

Fig. 25—Fan Blade Clearance

C95027

1/2 IN. MAX
FR OM FAN DECK

MOTOR SHAFT

MOTOR

—18—

Summary of Contents for 657A

Page 1: ...Also make sure the User s Manual and Replacement Guide are left with the unit after installation SAFETY CONSIDERATIONS Installation and servicing of air conditioning equipment can be hazardous due to...

Page 2: ...s 2 5 for unit dimensions All units are shipped in a horizontal discharge configuration for installation on a ground level slab All units can be converted to down flow discharge configurations for roo...

Page 3: ...h the roof curb Improperly applied gasketing also can result in air leaks and poor unit performance Curb should be level to within 1 4 in See Fig 8 This is necessary for unit drain to function properl...

Page 4: ...maximum horizontal extension of a partial overhang must not exceed 48 in IMPORTANT Do not restrict outdoor airflow An air restriction at either the outdoor air inlet or the fan discharge may be detri...

Page 5: ...unit has duct flanges on the supply and return air openings on the side of the unit See Fig 2 5 for connection sizes and locations When designing and installing ductwork consider the following CAUTIO...

Page 6: ...2 Heater limit switches may trip at air quantities below those recommended NOTE A 90 degree elbow must be provided in the supply ductwork to comply with UL Underwriters Laboratories codes for use with...

Page 7: ...recommended to be used for rigging Install brackets as follows Fig 7 657A Rigging Instructions UNIT SIZE CHART A CHART B Max Weight A B Max Weight C D LB KG IN MM IN MM LB KG IN MM IN MM 024 296 134...

Page 8: ...tional information Lifting holes are provided in base rails as shown in Fig 7 See Detail A or B B Refer to rigging instructions on unit A INSTALLATION 1 Position the lifting bracket assembly around th...

Page 9: ...ast 1 in lower than the unit drain pan condensate connection to prevent the pan from overflowing Prime the trap with water Connect a drain tube using a minimum of 3 4 in PVC 3 4 in CPVC or 3 4 in copp...

Page 10: ...uct Cover C95015 Fig 14 Indoor Blower Access Panel C950016 INDOOR BLOWER ACCESS PANEL REMOVE SCREWS Fig 15 Converting Blower Assembly to Vertical Airflow C950010 PLUG ASSEMBLIES RACEWAY FILLER BRACKET...

Page 11: ...oles in duct flanges as templates drill the remaining holes with the no 26 147 in drill 5 Fully secure the duct flanges using the remaining screws provided NOTE The finished kit installation accommoda...

Page 12: ...perimeter of the vertical discharge opening cover See Fig 13 9 Using a straight edge and sharp knife cut the insulation around the perimeter of the cover Remove the screws TABLE 1 PHYSICAL DATA UNIT...

Page 13: ...nit base Secure using screw removed in Step 7 Reconnect indoor fan motor leads and insert wire tie back into unit control box 13 Cover the horizontal duct openings Duct covers can be ordered as an acc...

Page 14: ...ground to minimize the pos sibility of personal injury if an electrical fault should occur This ground may consist of an electrical wire connected to the unit ground lug in the control compart ment o...

Page 15: ...the red lead to the contactor terminal from which the orange lead was disconnected 5 Using the wire nut removed from the red lead insulate the loose terminal on the orange lead 6 Wrap the wire nut wit...

Page 16: ...60 70 70 80 100 100 22 5 26 0 33 7 39 1 45 1 50 1 67 9 78 1 25 30 35 40 50 60 70 80 22 8 30 30 036 208 230 1 187 253 16 0 88 0 1 2 2 6 3 75 5 00 5 60 7 50 7 50 10 0 11 30 15 0 18 1 20 8 27 1 31 3 36 1...

Page 17: ...no additional leaks are not found 5 Charge unit with R 22 refrigerant using a volumetric charging cylinder or accurate scale Refer to unit rating plate for required charge Be sure to add extra refrige...

Page 18: ...room tem perature Observe that compressor outdoor fan and indoor blower motors start Observe that compressor and outdoor fan shut down when control setting is satisfied and that indoor blower shuts do...

Page 19: ...Fig 26 Wiring Diagram 024 to 042 208 230 60 1 C95037 19...

Page 20: ...Fig 27 Wiring Diagram 048 to 060 208 230 60 1 with ECM Indoor C95038 20...

Page 21: ...from obstructions and adjusted properly WARNING Disconnect electrical power to the unit and install lockout tag before changing blower speed Elec trical shock can cause serious injury or death Airflo...

Page 22: ...simultaneously through the Y and G terminals of the thermostat respectively On units with a compressor time delay relay there is a built in 5 minute 45 seconds delay between compressor starts Energiz...

Page 23: ...AT RANGE VIO setting or the AC HP SIZE BLU setting whichever is greater This may be a noticeable change in airflow When thermostat is satisfied contacts open deenergizing contactor and relay motors an...

Page 24: ...C INDOOR BLOWER AND MOTOR NOTE Motors without oilers are prelubricated Do not attempt to lubricate these motors For longer life operating economy and continuing efficiency clean accumulated dirt and g...

Page 25: ...1200 1400 1600 1800 2000 2200 5 20 0 030 0 033 0 037 0 042 0 047 0 052 0 060 0 067 0 075 TABLE 12 FILTER PRESSURE DROP IN WG UNIT SIZE FILTER SIZE IN 500 600 700 800 900 1000 1100 1200 1300 1400 1500...

Page 26: ...5 6 24 1 25 0 33 3 34 8 33 8 32 6 31 8 31 0 30 2 80 16 4 17 6 21 4 16 8 23 2 31 8 32 2 31 3 30 4 29 5 28 6 85 9 4 8 6 14 7 21 6 29 4 29 8 28 9 27 8 27 0 90 11 6 18 9 26 4 27 3 26 4 25 5 95 3 7 10 8 18...

Page 27: ...21 6 23 0 24 4 24 5 24 6 80 8 9 8 9 8 9 12 4 16 0 19 4 21 0 22 4 23 8 24 0 24 0 85 8 2 8 2 8 2 11 8 15 3 18 7 20 2 21 8 23 3 23 4 23 4 90 7 7 7 7 7 7 10 8 13 7 16 7 18 7 20 7 22 7 22 7 22 9 95 7 2 7...

Page 28: ...NOTE Refer to the heating and or cooling sequence of operation in this publication as an aid in determining proper control operation TABLE 13H SUPERHEAT CHARGING TABLE UNIT 060 TEMP F AIR ENT COND EV...

Page 29: ...evices that are of the fixed orifice type located in the header to the indoor and outdoor coils J LIQUID LINE STRAINER The liquid line strainer to protect metering device is made of wire mesh and loca...

Page 30: ...ay valve and is directed to the cooling liquid line check valve It is then condensed and directed through subcooling circuits and out to the strainer and the check valve in the heating liquid line 2 T...

Page 31: ...Dirty air filter Replace filter Dirty indoor or outdoor coil Clean coil Refrigerant overcharged Recover excess refrigerant Air in system Recover refrigerant evacuate system and recharge Heat Indoor a...

Page 32: ...ghtness III START UP Supply Voltage C S __________ S R __________ R C __________ Compressor Amps C __________ S __________ R __________ Indoor Evaporator Fan Amps __________ TEMPERATURE Outdoor Conden...

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