Lennox KHC092

Page 14
TABLE 3
MANUFACTURER'S NUMBERS
DRIVE
NO.
DRIVE COMPONENTS
ADJUSTABLE SHEAVE FIXED SHEAVE BELT
BROWNING NO. OEM PART NO. BROWNING NO. OEM PART NO. BROWNING NO. OEM PART NO.
1 1VP34x7/8 31K6901 AK61x1 100244-20 AX54 100245-25
2 1VP40x7/8 79J0301 AK59x1 31K6801 AX55 100245-26
3 1VP34x7/8 31K6901 AK46x1 100244-17 AX52 100245-33
4 1VP44x7/8 53J9601 AK74x1 100244-21 AX58 100245-34
5 1VP50x7/8 98J0001 AK69x1 37L4701 AX58 100245-34
6 1VP50x7/8 98J0001 AK64x1 12L2501 AX57 100245-28
10 1VP50x1-1/8 P-8-1977 BK77x1 49K4001 BX59 59A5001
11 1VP50x1-1/8 P-8-1977 BK67x1 100244-24 BX57 78L5301
12 1VP50x1-1/8 P-8-1977 BK62x1 100244-23 BX56 100245-11
Heating Start-Up
1- Set thermostat or temperature control device to
initiate a first-stage heating demand.
A first-stage heating demand (W1) will energize
compressors 1 and 2. Both outdoor fans are
energized with a W1 demand.
Note - L1 and L2 reversing valves are de-energized in the
heating mode.
Units With Optional Electric Heat -
An increased heating demand (W2) will energize
electric heat. Electric heat is also energized during
the defrost cycle (W1) to maintain discharge air
temperature.
Cooling Start-Up
IMPORTANT
If unit is equipped with a crankcase heater. Make
sure heater is energized 24 hours before unit start-
up to prevent compressor damage as a result of
slugging.
A-Start-Up
Supply Air Inverter Units - Refer to the Inverter
Start-Up section for further instruction on blower
control. See table 12 for full details on unit operation.
Compressor 1 is a two-stage compressor. Compressor 2
is a single-stage compressor.
1- Initiate first, second, and third stage cooling demands
according to instructions provided with thermostat.
2- No Economizer Installed in Unit -
See table 4 for cooling operation.
Units Equipped With Economizer -
When outdoor air is suitable, any combination of
thermostat demands will energize the economizer.
See table 5 for cooling operation.
2- Refrigerant circuits are factory charged with
HCFC-410A refrigerant. See unit rating plate for
correct amount of charge.
3- Units contain two refrigerant circuits or systems. See
figure 14.
TABLE 4
COOLING OPERATION - NO ECONOMIZER
T'Stat Compressors OD Fans
Y1 Compr. 1 Low Fan 1 On
Y1 + Y2 Compr. 1 Low; Compr. 2 On Both On
Y1 + Y2 + Y3 Compr. 1 High; Compr. 2 On Both On
TABLE 5
COOLING OPERATION - WITH ECONOMIZER
T'Stat Compressors OD Fans
Y1 Off Off
Y1 + Y2 Compr. 1 Low Fan 1 On
Y1 + Y2 + Y3 Compr. 1 High Fan 1 On
1
2
Y1 Demand =Outdoor Fan 1 Energized
Y2 Demand =Outdoor Fans 1 & 2 Energized
INDOOR COIL
STAGES 1 & 2
INTERTWINED
OUTDOOR COIL
STAGE 2
OUTDOOR COIL
STAGE 1
OUTDOOR
FAN 1
OUTDOOR
FAN 2
B4
B5
FIGURE 14
REFRIGERANT STAGES - TWO FANS