GMVC9 GCVC9 Installation Instructions
24
115 VOLT LINE CONNECTIONS
Before proceeding with electrical connections, ensure that the
supply voltage, frequency, and phase correspond to that speci-
fied on the unit rating plate. Power supply to the furnace must
be NEC Class 1, and must comply with all applicable codes. The
furnace must be electrically grounded in accordance with local
codes or, in their absence, with the latest edition of The Na-
tional Electric Code, ANSI NFPA 70 and/or The Canadian Elec-
tric Code CSA C22.1.
Use a separate fused branch electrical circuit containing prop-
erly sized wire, and fuse or circuit breaker. The fuse or circuit
breaker must be sized in accordance with the maximum
overcurrent protection specified on the unit rating plate. An
electrical disconnect must be provided at the furnace location.
Connect hot, neutral, and ground wires as shown in the wiring
diagram located on the unit’s blower door. For direct vent
applications, the cabinet opening to the junction box must be
sealed air tight using either an UL approved bushing such as
Heyco Liquid Tight or by applying non-reactive UL approved
sealant to bushing.
Line polarity must be observed when making field connections.
Line voltage connections can be made through either the right
or left side panel. The furnace is shipped configured for a left
side (right side for counterflows) electrical connection with the
junction box located inside the burner compartment. To make
electrical connections through the opposite side of the fur-
nace, the junction box must be relocated to the other side of
the burner compartment prior to making electrical connections.
To relocate the junction box, follow the steps shown below.
NOTE: Wire routing must not to interfere with circulator blower
operation, filter removal, or routine maintenance.
JUNCTION BOX RELOCATION
E
DGES
OF
SHEET
METAL
HOLES
MAY
BE
SHARP
. U
SE
GLOVES
AS
A
PRECAUTION
WHEN
REMOVING
HOLE
PLUGS
.
WARNING
T
O
PREVENT
PERSONAL
INJURY
OR
DEATH
DUE
TO
ELECTRIC
SHOCK
,
DISCONNECT
ELECTRICAL
POWER
BEFORE
INSTALLING
OR
SERVICING
THIS
UNIT
.
WARNING
Line voltage connections can be made through either the
right or left side panel. The furnace is shipped configured
for a left side electrical connection. To make electrical con-
nections through the opposite side of the furnace, the junc-
tion box must be relocated to the right side prior to making
electrical connections. To relocate the junction box, per-
form the following steps.
1. Remove the burner compartment door.
2. Remove and save the two screws securing the junction
box to the side panel.
3. Relocate junction box and associated plugs and grommets
to opposite side panel. Secure with screws removed in
step 2.
To ensure proper unit grounding, the ground wire should run
from the furnace ground screw located inside the furnace junc-
tion box all the way back to the electrical panel. NOTE: Do not
use gas piping as an electrical ground. To confirm proper unit
grounding, turn off the electrical power and perform the follow-
ing check.
1. Measure resistance between the neutral (white) connection
and one of the burners.
2. Resistance should measure 10 ohms or less.
This furnace is equipped with a blower door interlock switch which
interrupts unit voltage when the blower door is opened for ser-
vicing. Do not defeat this switch.
24 VOLT THERMOSTAT WIRING
As a two-stage non-communicating furnace, the furnace inte-
grated control module provides terminals for both “W1” and
“W2”, and “Y1” and “Y2” thermostat connections. This allows
the furnace to support the following system applications: ‘Two-
Stage Heating Only’, ‘Two-Stage Heating with Single Stage Cool-
ing’, and ‘Two-Stage Heating with Two-Stage Cooling’. Refer to
the following figures for proper connections to the integrated
control module.
Low voltage connections can be made through either the right or
left side panel. Thermostat wiring entrance holes are located in
the blower compartment. The following figure shows connec-
tions for a “heat/cool system”.
This furnace is equipped with a 40 VA transformer to facilitate
use with most cooling equipment. Consult the wiring diagram,
located on the blower compartment door, for further details of
115 Volt and 24 Volt wiring.
NOTE: For single stage cooling applications, a jumper may be
required between Y1 and Y2 at the furnace control in order to
achieve the desired single stage cooling airflow. Use of ramping
profiles and dehumidification features require a jumper between
Y1 and O.
NOTE: Thermostat “R” required if outdoor unit is equipped
with a Comfort Alert™ module or if the outdoor unit is a
part of the ComfortNet™™ family of equipment AND is wired
as a non-communicating system.