6
440 04 6001 00
Specifications subject to change without notice.
BL
W
NUETRAL
ST
A
T
US CODE LED
SEC-2 SEC-1
EAC-2 L2
FUSE 3-AMP
0.5 AMP@24VAC
HUM
TEST/TWIN
G Com
W
Y R
24V
120 180
90 150
BLOWER OFF-DELAY
COOL HEA
T
SPARE-1 SPARE-2
PR-1
L1
PL2 1
24-V THERMOSTAT
TERMINALS
3-AMP FUSE
LED OPERATION &
DIAGNOSTIC LIGHT
115-VAC(L2)NEUTRAL
CONNECTIONS
COOL
HEAT
SPARE-1
SPARE-2
BLOWER SPEED
SELECTION TERMINALS
EAC-1 TERMINAL
(115-VAC 1.0 AMP MAX.)
115 VAC (L1) LINE
VOLTAGE CONNECTION
PL2-HOT SURFACE
IGNITER & INDUCER
MOTOR CONNECTOR
PL1-LOW VOLTAGE MAIN
HARNESS CONNECTOR
TRANSFORMER 24-VAC
CONNECTIONS
HUMIDIFIER TERMINAL
(24-VAC 0.5 AMP MAX.)
TWINNING AND/OR
COMPONENT TEST
TERMINAL
BLOWER OFF-DELAY
J2
J2 JUMPER
PL
T
PL
1
SPARE-3
SPARE-3
1
A11619
Figure 2
−
Example of Single Stage Furnace Control
Adjust Temperature Rise
NOTE
: Blower door must be installed when taking
temperature rise reading. Leaving blower door off will result
in incorrect temperature measurements, due to possible
changes in duct static pressure and airflow.
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in:
S
Overheating the heat exchangers or
condensing flue gases in heat exchanger
areas not designed for condensate.
S
Shortened furnace life.
S
Component damage.
Temperature rise must be within limits specified on
furnace rating plate. Recommended operation is at
midpoint of rise range or slightly above.
CAUTION
!
Jumper R to W to check gas-heat temperature rise. Do not
exceed temperature rise ranges specified on unit rating
plate.
This furnace must operate within the temperature rise
ranges specified on the furnace rating plate. Determine the
air temperature as follows:
1. Place duct thermometers in return and supply ducts
as close to furnace as possible. Be sure
thermometers do not “see” heat exchangers so that
radiant heat does not affect thermometer readings.
This is particularly important with straight
−
run ducts.
2. When thermometer readings stabilize, subtract
return
−
air temperature from supply
−
air temperature to
determine temperature rise.
If the temperature rise is outside this range, check the
following:
1. Gas input rate.
2. Derate for altitude if applicable.
3. Return and supply ducts for excessive restrictions
causing static pressures greater than 0.50
−
in. w.c.
(125 Pa)
4. Adjust temperature rise by adjusting blower speed.
S
Increase blower speed to reduce temperature rise.
S
Decrease blower speed to increase temperature
rise.
