Installation Instructions
Accessory
Thermostat Kit
KGATT0101VSP
NOTE: Read entire instruction manual before starting the installation.
INTRODUCTION
These instructions cover installation of a 2-stage thermostat interface kit Part No. KGATT0101VSP on variable-speed condensing furnaces.
DESCRIPTION AND USUAGE
This kit is intended for use with any Parker 2-stage thermostat and allows the thermostat to override the furnace’s internal thermostat algorithm.
In addition, this kit may also be used in conjunction with other 24-v 2-stage thermostats which primarily operate in the low-fire mode at the start
of the heating cycle. The following 2-stage thermostats are compatible with the variable-speed condensing furnaces: Honeywell T874F1015 and
T8621C7008; White-Rodgers 1F91-3.
SEQUENCE OF OPERATION
1. Thermostat call for W1 or HEAT 1 only: The furnace will operate in low fire only with the exception of the first minute of high- fire on
each cycle.
2. Thermostat call for W2 or HEAT2 only: The furnace ignores the request for high heat until the thermostat call for W1 or HEAT1.
3. Thermostat call for W1 or HEAT1 and W2 or HEAT2 simultaneously: The furnace will operate in high fire only, even if W2 or HEAT2
is de-energized.
4. Thermostat call for W1 or HEAT1 followed by a thermostat call for W2 or HEAT2: The furnace will operate in low fire until the thermostat
calls for W2 or HEAT2. Then the furnace proceeds to operate in high fire and remains in high fire until the call for heat is satisfied (when
W1 or HEAT1 is de-energized), even if W2 or HEAT2 is de-energized. Consult product engineering to determine thermostat compatibility
if you intend to use a thermostat that is not listed above.
NOTE: This kit is not compatible with variable-speed outdoor units when used in conjunction with a Parker 2-stage Home Zone® thermostat;
when the thermostat is configured for these units, the thermostat relays do not function. Each 2-stage thermostat interface kit comes completely
assembled with a relay wired for easy installation.
WARNING: Turn OFF power at main disconnect switch before starting installation to avoid possibility of electrical
shock.
INSTALLATION
The following steps should be performed by a qualified service person:
1. Turn OFF power at main disconnect.
2. Remove access doors.
3. Remove control box.
4. Connect 3-pin Molex connector to furnace control board receptacle P5. (See Fig.1.)
5. Secure green ground wire from cable shielding and black wire from relay to lower left control board mounting screw. (See Fig. 1.) DO NOT
cut or remove wire tie, route wire as shown in Fig. 1.
6. Put setup switch No. 2 on furnace control board to ON (up) position. See Fig. 1 for setup switch location.
7. Place 3-in. edge guard on front left side of control box cover. (See Fig. 1.)
8. Reinstall control box cover using only right side mounting screw.
9. Secure relay and left side of control box cover in place using left side control box cover mounting screw. (See Fig. 1.)
NOTE: When the condensate drain pipe exits the left-hand side of the furnace, rotate the relay 90° in either direction to avoid interference.
10. Connect thermostat wire for low-fire stage W1 or HEAT1 to W terminal on furnace control board.
11. Connect brown interface wire from relay using field-supplied wire nut to thermostat wire for high-fire stage W2 or HEAT2.
Form:
AG-GATT-01
Cancels:
IIK 398B-60-4/58SXB-12SI
Printed in U.S.A.
7-92
Catalog No.
92-33GA-TT1
CONTROL BOX
COVER
EDGE
GUARD
Q1
GREEN WIRE
P1
CB1
R59
K1
K2
C24
P5
CONTROL BOX
COVER
MOUNTING
SCREW
SETUP
P4
R
V
W
G
C
TO W1 OF THERMOSTAT
RELAY
SETUP SWITCHES
WIRE NUT
BROWN WIRE
BLACK WIRE
TO W2 OF THERMOSTAT
A89216
Fig. 1—Two-Stage Thermostat Interface Kit
12. Reinstall access door.
13. Turn ON electrical power and wait 30 sec before setting room thermostat to ‘‘call for heat.’’
14. If applicable, set thermostat heat anticipation per the thermostat manufacturer’s recommendations. On thermostats that use a program
selectable cycle rate, set thermostat for 3 to 4 cycles per hour.
© 1995 CAC / BDP
P.O. Box 70, Indianapolis, IN 46206
15042
—2—
Book/Tab: 1/6a 4/8a
Catalog No. 92-33GA-TT1