3. No humidifier connection
terminal.
4. No 'FAN" and "HEAT/COOL"
connections.
5. There are only two indicator
lights.
6. The "OK" light blinks to indicate
a problem.
Thermostat Connections
The thermostat connections use
screw terminals. Also, the thermostat
connections are kept within the
furnace control box.
FIGURE93
THERMOSTAT SCREW
CONNECTION
Motor Wiring Connections
The motor wiring connections are
basically the same as with current
control boards. However, there are
no ·'FAN" or "HEAT/COOL"
terminals. Connect the heating motor
speed wire to the "HEAT' terminal,
connect the cooling motor speed
wire to the "COOL" terminal. Connect
the unused motor speed wire to the
''M1" terminal
FIGURE 94
MOTOR WIRE CONNECTIONS
TROUBLESHOOTING
Indicator Lights
There are two indicator lights on the
UTEC 1012-925 control. The ''OK"
light indicates if the board is
operational, and the "FLAME" light
indicates the flame sensor microamp
flame proving capability.
The "OK" light has troubleshooting
features. If a specific problem takes
the furnace off line. the light flashes
a certain number of times to indicate
; the problem.
FIGURE 95
INDICATOR LIGHTS
~
_, ,. _,.?-,- 'i
"'
{( ,-
The following lists the sequence of
"OK' light flashes and the associated
problem.
1 One blink followed by a 2 sec.
pause - soft (one hour) lock out.
2. Two blinks followed by a 2 sec.
pause - open pressure switch.
FIGURE 96
3. Three blinks followed by a 2 sec.
pause - open limit switch.
4. Four blinks followed by a 2 sec.
pause - shorted pressure switch.
INTEGRATED FURNACE
CONTROLS USED ON THE 90
PLUS GAS FURNACE WITH
DIRECT SPARK IGNITION (OSI)
The (-)GRA / (-)GTA series of 90
Plus gas furnace now use direct
spark ignition. There are two
controls: the UTEC and Johnson
Controls DSI IFC's. As with earlier
HSI controls, both operate similarly,
use remote flame sense. and are
interchangeable.
UTEC 1028-927 AND JCI
G961 DAJ-2401 CONTROLS
The UTEC 1028-927 control has the
factory part number 62-24140--01.
They are found on units with serial
numbers beginning with EJ or EL.
The Johnson Controls G961 DAJ-
2401
has the factory part number
62-24136-01. They are found on
units with serial numbers beginning
with
EH or EK. (-)GTA units
converted to direct spark beginning
with
date code F4296. (-)GRA units
converted to direct spark beginning
with
date code F0197.
Both have two green and one amber
LED's. These LED's serve the same
purpose as those found on previous
hot surface ignition controls. Both
UTEC 1028-927 OSI FURNACE CONTROL
79
To Next Page
Loading...