Page 29
XPG15 SERIES
STEP 3 SYSTEM OPERATION CHECKS
The table below shows which terminals should have 24VAC inputs or outputs during certain operation modes. (Example: In
the cooling mode, there should be 24VAC between Y1 and C on the demand defrost control terminal strip).
Operation Mode
ComfortSense®
Gas Furnace
Dedicated Heat Pump (XPG15)
24VAC INPUTS/
OUTPUTS
"
Y1
W1
W2
O
G
E
L
Y1
Y2
W1
W2
G
O
Y1
W
IN
RL/
K229
O
Y1
OUT
W
OUT
Cooling Mode
OFF
X
X
Cooling
X
X
X
X
X
X
X
X
X
Heating Mode (Outside Temperature above 32ºF)
First Stage Heat-
ing (Heat Pump)
X
X
X
X
X
X
Second Stage
Heating (First
Stage Gas Heat)
X
X
X
X
X
X
X
X
X
X
Third Stage Heat-
ing (Second Stage
Gas Heat)
X
X
X
X
X
X
X
X
X
X
X
X
Heating Mode (Outside Temperature below 32ºF
)
First Stage Heat-
ing (First Stage
Gas Heat)
X
X
X
X
X
X
X
X
X
Second Stage
Heating (Second
Stage Gas Heat)
X
X
X
X
X
X
X
X
X
X
X
Defrost Mode
Power Defrost
X
X
X
X
X
X
X
Natural Defrost
X
X
X
X
X
X
Emergency Heat
Mode
Emergency Heat
Mode
X
X
X
X
X
X
X
Low and High
Pressure (Lock−
Out Mode)
Cooling LPS, HPS
X
X
X
X
X
X
X
X
Heating HPS
X
X
X
X
X
Heating LPS
X
X
X
X
X
X
X
X
X
IMPORTANT
Set−up is critical to ensure proper system operation. Refer to installation instructions packaged with the
unit, as well as XPG15 service manual. Both documents are available from
www.LennoxDaveNet.net
.
Field−Installed Relay
K229
− De−energizes
Y1
and
G
inputs to furnace (factory−provided and field−installed at indoor
unit).
NOTES
1. For proper operation the demand defrost control must have 24VAC between
R
(system power input) and
C
(system
common). The above chart shows which terminals should have 24VAC inputs or outputs during certain operation
modes. (
Example
: In the cooling mode, there should be 24VAC between
Y1
and
C
on the demand defrost control
terminal strip).
2. Placing a jumper on the demand defrost control’s TEST pins will not activate the heat pump out of inactive mode.
(24VAC power must be cycled to the demand defrost control to activate the heat pump out of inactive mode).
3. Demand defrost control will not output a
W
out signal when the outdoor temperature is above 65ºF (18ºC).
4. If the demand defrost control enters a low pressure LOCKOUT during heating mode, the outdoor unit will enter the heat
pump inactive mode. The demand defrost control will flash the low pressure code. If the room thermostat calls for Y1
heating in low pressure LOCKOUT, the demand defrost control will alternately display two codes four (4) seconds
for the low pressure LOCKOUT, and then four (4) seconds heat pump inactive − gas mode active code.
