Lennox G21Q Series Unit Information

C
Page 93
G21V/GSR21V OPERATION SEQUENCE AND JUMPERS SUMMARY WITH VSP2−1 (HEATING)
MATCH UP JUMPER COMMENTS OR SEQUENCE
SingleStage Heating
Blower operates on heating
speed. Modulation control S78
may not cycle the unit. If NM is
used instead of W1, blower op
erates on heating speed and no
modulation occurs.
TwoStage Heating
Heating Blower
Jumper in
position # 2
Blower operates on the low
speed heat/cool tap during
the first stage of heating.
Modulation control S78 will
cycle the unit. Blower oper
ates on the high speed heat
tap during second stage heat
ing. Modulation control S78
may not cycle the unit.
Harmony Heating
Heating Blower
Jumper MUST BE
in position # 2
Blower operates on PWM
signal generated by Har
mony. Harmony overrides
blower speed taps. Blower
speed varies according to
zone demand.
TABLE 18
WIRING CONNECTIONS
W1
W2
RG
Y1
Y2
DS
NM
W1
W2
RG
Y1
Y2
DS
C
NM
W1
W2
RG
Y1
Y2
DS
C
NM
S1
THERMOSTAT
TB1 TERMINAL STRIP
S1
THERMOSTAT
TB1 TERMINAL STRIP
TB1 TERMINAL STRIP
ZONE
CONTROLLER
A1
HARMONY
FOR COOLING JUMPERS
SEE TABLE 19
Heating Blower
Jumper in
position # 2
Heating Blower
Jumper in
position # 1
NOTE: TwoStage heating is
not available when using the
nonmodulation NM terminal
Blower operates on low
speed. Modulation control
S78 will cycle the unit. If NM is
used instead of W1, blower
operates on low speed and no
modulation occurs.
*
*
If no modulation
is desired, wire
heat demand
(W1) from ther
mostat to NM on
terminal strip.

Lennox G21Q Series Specifications

General

Brand	Lennox
Model	G21Q Series
Category	Industrial Equipment
Language	English