Page 35
TABLE 18 
300 Reheat Compressor 1 Frequency 68Hz - 581023-01
Outdoor 
Coil 
Entering 
Air 
Temp
Circuit 1 Circuit 2 Circuit 3 Circuit 4
Dis. 
+10 
psig
Suc. 
+5 
psig
Dis. 
+10 
psig
Suc. 
+5 
psig
Dis. 
+10 
psig
Suc. 
+5 
psig
Dis. 
+10 
psig
Suc. 
+5 
psig
 274 121  120  114 275 120
  124  122 301 123 317 128
   387 124  131  135
 415  442 127  137 414 141
  132  130 447 142  144
 525  558 133 502 145  147
-
1 -   Using the same thermometer, compare liquid 
temperature to outdoor ambient temperature.
Approach Temperature = Liquid temperature (at con-
denser outlet) minus ambient temperature.
2 -   Approach temperature should match values in table 
      
shown indicates an undercharge. An approach 
temperature less than value shown indicates an 
overcharge.
3 -   The approach method is not valid for grossly over or 
a guide for typical operating pressures.
TABLE 19 
APPROACH TEMPERATURES - FIN/TUBE COIL
Unit
Liquid Temp. Minus Ambient Temp.
1st Stage 2nd Stage 3rd Stage 4th Stage
Std.
+ 1 
+0.5)
+ 1 
+0.5)
+ 1 
+0.5)
NA
Reheat
+1 
+0.5)
+1 
+1 
+0.5)
NA
180 
Std.
+ 1 
+0.5)
+ 1 
+ 1 
+0.5)
NA
180 
Reheat
+ 1 
+0.5)
+ 1 
+0.5)
+ 1 
+0.5)
NA
210 
Std.
+ 1 
+0.5)
+ 1 
+ 1 
+0.5)
+ 1 
+0.5)
210 
Reheat
+ 1 
+0.5)
+ 1 
+0.5)
 + 1 
+0.5)
+ 1 
+0.5)
240 
Std.
+ 1 
+0.5)
+ 1 
+0.5)
+ 1 
+0.5)
+ 1 
+0.5)
240 
Reheat
+ 1 
+0.5)
+ 1 
+0.5)
+ 1 
+0.5)
300 
Std.
+1 
+0.5)
+1 
+0.5)
+1 
+0.5)
+1 
+0.5)
300 
Reheat
+1 
+0.5)
+0.5)
+1 
+0.5)
+1 
+0.5)
IV-STARTUP - OPERATION
Refer to startup directions and to the unit wiring diagram 
when servicing. See unit nameplate for minimum circuit 
ampacity and maximum fuse size.
A-Preliminary and Seasonal Checks
1 -   Make sure the unit is installed in accordance with 
the installation instructions and applicable codes.
2 -         
installed for loose connections. Tighten as required. 
Refer to unit diagram located on inside of unit 
control box cover.
3 -   Check to ensure that refrigerant lines are in good 
condition and do not rub against the cabinet or 
other refrigerant lines.
4 -   Check voltage. Voltage must be within the range 
listed on the nameplate. If not, consult power 
company and have the voltage corrected before 
starting the unit.
5 -   Recheck voltage and amp draw with unit running. If 
voltage is not within range listed on unit nameplate, 
stop unit and consult power company. Refer to unit 
nameplate for maximum rated load amps.
  Inspect and adjust blower belt (see section on 
Blower Compartment - Blower Belt Adjustment).
        
circuits
NOTE-Crankcase  heaters  must  be  energized  24  hours 
before attempting to start compressor. Set thermostat so 
that there is no demand to prevent compressor from cy-
cling.
Apply power to unit.
1 -        
according to instructions provided with thermostat.
2 -   First-stage thermostat demand will energize 
indoor blower in Low Cooling CFM. Second-stage 
thermostat demand will energize indoor blower 
in High Cooling CFM. Both demands energize 
compressor 1 (variable speed compressor). 
The remaining compressors will be energized to 
modulate the discharge air temperature.
3 -   156, 180-
Units contain three refrigerant circuits or systems.
210, 240, 300 -
Units contain four refrigerant circuits or systems.
4 -   Each refrigerant circuit is separately charged with 
R410A refrigerant. See unit rating plate for correct 
amount of charge.
5 -   Refer to the Refrigerant Check and Charge section 
to check refrigerant charge.