935CA: Installation, Start-up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
27
ACCESSORIES
1. Electronic Air Cleaner (EAC)
Connect an accessory Electronic Air Cleaner (if used) using 1/4-in.
female quick connect terminals to the two male 1/4-in.
quick-connect terminals on the control board marked EAC-1 and
EAC-2. The terminals are rated for 115VAC, 1.0 amps maximum
and are energized during blower motor operation.
2. Humidifier (HUM)
The HUM terminal is a 24 VAC output, energized when the blower
is operating during a call for heat. Connect an accessory 24 VAC,
0.5 amp. maximum humidifier (if used) to the 1/4-in. male
quick-connect HUM terminal and COM-24V screw terminal on the
control board thermostat strip.
NOTE:: If the humidifier has its own 24 VAC power supply, an
isolation relay may be required. Connect the 24 VAC coil of the
isolation relay to the HUM and COM/24V screw terminal on the
control board thermostat strip, see
Fig. 42
.
3. Communication Connector (communication connection) This
connection is used when the furnace is controlled by an optional
communicating User Interface instead of a standard thermostat. The
communication plug is supplied with the User Interface. Refer to
the instructions supplied with the User Interface for complete
details, see
Fig. 42
.
4. Outside Air Thermistor (OAT)
The OAT connection is used in conjunction with communicating
User Interface. It is not required when the furnace is controlled by a
standard type thermostat. Refer to the instructions supplied with the
User Interface for complete details.
Alternate Power Supplies
This furnace is designed to operate on utility generated power which has
a smooth sinusoidal waveform. If the furnace is to be operated on a
generator or other alternate power supply, the alternate power supply
must produce a smooth sinusoidal waveform for compatibility with the
furnace electronics. The alternate power supply must generate the same
voltage, phase, and frequency (Hz) (
Table 13
) or the furnace rating plate.
Power from an alternate power supply that
is non-sinusoidal may
damage the furnace electronics
or cause erratic operation.
Contact the alternate power supply manufacturer for specifications and
details.
A11157
Fig. 40 – Field-supplied Isolation Relay for Humidifiers with Internal Power Supply
A200310
Fig. 41 – Typical Single-Stage Wiring Diagram
24 V
Coil
To Humidifier Leads
To Com/24V Screw Terminal
on Thermostat Strip
To HUM Terminal On
Furnace Control Board
To Humidifier Leads
115-VOLT FIELD-
SUPPLIED
FUSED
DISCONNECT
JUNCTION
BOX
CONTROL
BOX
24-VOLT
TERMINAL
BLOCK
THREE-WIRE HEATING- ONLY
FIVE
WIRE
NOTE 2
NOTE 1
1-STAGE
THERMOSTAT
TERMINALS
FIELD-SUPPLIED
FUSED DISCONNECT
CONDENSING
UNIT
FURNACE
COM
R
W
C
Y
R
G
GND
GND
FIELD 24-VOLT WIRING
FIELD 115-, 208/230-, 460-VOLT WIRING
FACTORY 24-VOLT WIRING
FACTORY 115-VOLT WIRING
Connect Y/Y2-terminal as shown for proper operation.
Some thermostats require a "C" terminal connection as shown.
If any of the original wire, as supplied, must be replaced, use
same type or equivalent wire.
208/230- OR
460-VOLT
THREE
PHASE
208/230-
VOLT
SINGLE
PHASE
WHT
BLK
WHT
BLK
W/W1
W2
Y/Y2
G
NOTES:
1.
2.
3.
BLOWER DOOR SWITCH
BLOWER DOOR SWITCH
