Start Up - Operation - Lennox LCH092H Unit Information

TABLE 22
LCH152U
Outdoor Coil
Discharge +10
Entering Air
Temp
655 F
755 F
855 F
955 F
1055 F
1155 F
F-Charge Verification - Approach Method - AHRI Testing
(Fin/Tube Coil Continued)
1 Using the same thermometer, compare liquid tempera­
ture to outdoor ambient temperature.
Approach Temperature = Liquid temperature (at con­
denser outlet) minus ambient temperature.
2 Approach temperature should match values in table
23. An approach temperature greater than value
shown indicates an undercharge. An approach tem­
perature less than value shown indicates an over­
charge.
3 The approach method is not valid for grossly over or
undercharged systems. Use tables20 through22 as a
guide for typical operating pressures.
TABLE 23
APPROACH TEMPERATURE - 094, 122, 152
Liquid Temp. Minus Ambient Temp.
Unit
094
122, 152
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 Inspect all electrical wiring, both field and factory installed
for loose connections. Tighten as required. Refer to unit di­
agram 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,
Suction +5 psig
psig
266 129
305 132
346 134
391 138
443 141
498 143
Full Load (Both Compressors)
5°F + 1 (2.8°C + 0.5)
4°F + 1 (2.2°C + 0.5)
stop unit and consult power company. Refer to unit
nameplate for maximum rated load amps.
6 Inspect and adjust blower belt (see section on Blower
Compartment - Blower Belt Adjustment).
B-Cooling Startup See figures 22, 23 or 24
for circuits
NOTE-Crankcase heaters must be energized 24 hours be­
fore attempting to start compressor. Set thermostat so that
there is no demand to prevent compressor from cycling.
Apply power to unit.
LCH092H, 102H, 120H and 150S, 150H (Figure 22 or 23)
1 Initiate first and second stage cooling demands ac­
cording to instructions provided with thermostat.
2 First-stage thermostat demand will energize compres­
sor 1 and condenser fans 1 and 2. Second-stage ther­
mostat demand will energize compressor 2.
3 Units contain two refrigerant circuits or stages.
4 Each refrigerant circuit is separately charged with re­
frigerant. See unit rating plate for correct amount of
charge.
LCH094U, 122U and 152U (Figure 24)
1 Initiate first and second stage cooling demands ac­
cording to instructions provided with thermostat.
2 First-stage thermostat demand will energize compres­
sor 1 and condenser fans 1, 2 and 3 on low speed..
Second-stage thermostat demand will energize com­
pressor 2 and condenser fans 1, 2 and 3 on high speed.
3 Units contain one common (tandem) refrigerant circuit.
4 Refrigerant circuit is charged with refrigerant. See unit
rating plate for correct amount of charge.
REFRIGERANT CIRCUITS -
EVAPORATOR
COIL STAGE 2
2
Page 56
Fin/Tube Coil
(BOTH FANS ARE ENERGIZED
WITH A Y1 DEMAND)
1
EVAPORATOR
COIL STAGE 1
FIGURE 22