Low Voltage Terminal Strip Tb1; Imc1 Motor; Imc2 Motor - Lennox G21Q3-40 Unit Information

3 − Low Voltage Terminal Strip TB1
A low voltage terminal strip (TB1) with thermostat markings is
located outside the control box. See figures 3, 4 and 5.
Q" SERIES TERMINAL STRIP TB1
FUSE 2 AMP AGC FAST
BLOW
R W Y G C
FIGURE 3
V" SERIES IMC1 TERMINAL STRIP TB1
G Y1 Y2
W1 DS
W2 C
R HB
*Y is used as a terminal block to connect the
FUSE
outdoor unit to the thermostat. It makes no
3 AMP MDX SLOW BLOW
internal connection to unit controls.
FIGURE 4
V" SERIES IMC2 TERMINAL STRIP TB1
G
NM
W1
W2
3 AMP MDX SLOW BLOW
FIGURE 5
The following terminal designations are unique to V" se
ries with the IMC1 motor:
R" This signal provides 24VAC to the thermostat and, in
zoning applications, to the zone control.
DS " This is the speed regulation input that switches the
blower from LOW to HIGH speed in cooling mode. DS is
the PWM (pulse width modulation) input in zoning ap
plications. When used with the CCB1 it is a 12 17VDC
signal. When used without the CCB or Harmony it is a
24 VAC signal from the thermostat.
HB" This is an output signal, to tell the zone control when
the electronically controlled blower is energized from
either a heating demand or a tripped secondary limit.
The following terminal designations are unique to V" series
units with the IMC2 motor:
R" This signal provides 24VAC to the thermostat and, in Har
mony II zoning applications, to the control center.
R 24VAC OUTPUT
W HEATING DEMAND INPUT
Y COOLING WIRING
G BLOWER DEMAND INPUT
C COMMON
*Y is used as a terminal block to
connect the outdoor unit to the
thermostat. It makes no internal
connection to unit controls.
R 24VAC OUTPUT
W1 1st STAGE HEATING DEMAND INPUT
W2 2nd STAGE HEATING DEMAND INPUT
G BLOWER DEMAND INPUT
Y1 1st STAGE COOLING CONNECTION
Y2 2nd STAGE COOLING CONNECTION
DS PWM, AC OR DC INPUT
C COMMON 24 VAC
HB SENSING OUTPUT FOR HEATING
BLOWER
R C
DS
Y1
Y2
FUSE
DS" This is the speed regulation input that switches
the blower from LOW to HIGH speed, in cooling
mode. DS is the PWM (pulse width modulation) in
put in zoning applications that use Harmony II zon
ing system.
NM" This terminal is used for non−zoning (Non−Harmony),
non−modulating applications where heat exchanger mod
ulation is NOT desired. The heat demand from the ther
mostat should be wired to this terminal instead of W1.
For units with the IMC2 motor do not connect the
heat demand wire to both the W1 and the NM ter
minals. Damage to the unit will occur. Use the W1
terminal for zoning (Harmony) applications and
the NM terminal for non−zoning (Non−Harmony)
applications.
W1" This terminal is used for zoning (Harmony) modulating
applications where heat exchanger modulation IS de
sired. This terminal is also used for the first stage of a two−
stage heating application.
W2" This terminal is used for two−stage heating. Two−stage
heating is not available when using the non−modulating
NM terminal.
For field wiring to terminal strips see figures 3, 4 and 5. See
tables 2 and 3 for jumper connections.
TB1 TERMINAL STRIP JUMPERS V" MODELS
APPLICATION
Single Stage Heating
Single Speed Compressor,
No CCB1, Without Harmony
Two Speed Compressor, No
CCB1, Without Harmony
CCB1 With Single Speed or Two
Speed Compressor, Without Harmony
*Never Jumper Y2" to DS" when a CCB1 control is used.
Damage to the CCB1 will occur.
TB1 TERMINAL STRIP JUMPERS V" MODELS
APPLICATION
Single Stage Heating
Single Speed Compressor,
No CCB1, Without Harmony
Two Speed Compressor, No
CCB1, Without Harmony
CCB1 With Single Speed or Two
Speed Compressor, Without Harmony
*Never Jumper Y2" to DS" when a CCB1 control is used.
Damage to the CCB1 will occur.
NOTE − For single stage heat application with the IMC2 mo
tor, VSP2−1 will have a selector pin for single or second
stage heating. See figure 13.
Refer to tables 18 through 22 for a complete listing of all jump
ers used.
Page 13
CAUTION
TABLE 2

IMC1 MOTOR

JUMPERS REQUIRED
HB" Jumpered to W2"
DS" Jumpered to G"
DS" Jumpered to Y2"
No Jumpers Required*
TABLE 3

IMC2 MOTOR

JUMPERS REQUIRED
See Figure 13
For Pin Setting
DS" Jumpered to G"
DS" Jumpered to Y2"
No Jumpers Required*