Electrical Controls And Wiring - Carrier 100 Series Service And Maintenance Procedures Manual

BLK BLK
WHT WHT
GND
115-VOLT FIELD-
SUPPLIED
FUSED
DISCONNECT
Never use a match or other open flame to check for gas leaks.
Use a soap-and-water solution. A failure to follow this
warning could result in fire, personal injury, or death.
18. Replace outer access door.
Step 4—Electrical Controls and Wiring
There may be more than 1 electrical supply to the unit. Check
accessories and cooling unit for additional electrical supplies.
The electrical ground and polarity for 115-v wiring must be
properly maintained. Refer to Fig. 6 for field wiring information
and to Fig. 7 for furnace wiring information.
NOTE: If the polarity is not correct, the STATUS LED on the
control will flash rapidly and prevent the furnace from heating.
The control system also requires an earth ground for proper
operation of the control and flame-sensing electrode.
The 24-v circuit contains an automotive-type, 3-amp fuse located
on the control. (See Fig. 8.) Any shorts of the 24-v wiring during
installation, service, or maintenance will cause this fuse to blow. If
fuse replacement is required, use ONLY a 3-amp fuse. The control
LED will display status code 24 when fuse needs to be replaced.
With power to the unit disconnected, check all electrical connec-
tions for tightness. Tighten all screws on electrical connections. If
any smoky or burned connections are found, disassemble the
connection, clean all parts, and wire conductors, and reassemble
properly and securely.
Reconnect electrical power to the unit and observe unit through 1
complete operating cycle. Electrical controls are difficult to check
without proper instrumentation; if there are any discrepancies in
the operating cycle, contact your dealer and request service.
The control in this furnace is equipped with a Light-Emitting
Diode (LED) status code light to aid in installation, servicing, and
troubleshooting. It can be viewed through the sight glass or
window in blower access door. The control indicates status with
NOTE 2
W
FIVE
WIRE
THREE-WIRE
HEATING-
ONLY
W2
COM
W/W1
NOTE 1
Y/Y2
JUNCTION
BOX
R
CONTROL
G
BOX
24-VOLT
TERMINAL
BLOCK
FURNACE
Fig. 6—Heating and Cooling Application Wiring Diagram
1-STAGE
THERMOSTAT
C Y R G
TERMINALS
CONDENSING
NOTES: 1. Connect Y/Y2-terminal as shown for proper operation.
2. Some thermostats require a "C" terminal connection as shown.
3. If any of the original wire, as supplied, must be replaced, use
same type or equivalent wire.
the LED on continuously, rapid flashing, or a code composed of 2
digits. The first digit is the number of short flashes, the second
digit is the number of long flashes.
For an explanation of status codes, refer to service label located on
blower access door or Fig. 9, and the troubleshooting guide at the
end of this procedure.
The control stores 5 status codes for a period of 72 hrs.
The stored status codes will NOT be erased from the control
memory, if 115- or 24-v power is interrupted.
1. To retrieve status codes, proceed with the following:
NOTE: NO thermostat signal may be present at control, and all
blower-OFF delays must be completed.
a. Leave 115-v power to furnace turned on.
b. Remove outer access door.
c. Look into blower access door sight glass for current LED
status. Removing blower access door will open blower
access door switch and terminate 115-v power to control so
that status code is not displayed.
d. BRIEFLY remove either wire from the main limit (LS) or
draft safeguard (DSS) switch until LED goes out, then
reconnect it.
NOTE: If wire to LS or DSS is disconnected longer than 4 sec,
main blower starts, and retrieval request is ignored.
2. When above items have been completed, the LED flashes a
status code 4 times. Record this status code for further
troubleshooting.
After the LED flashes a status code four times, BRIEFLY remove
wire again from LS or DSS switch until LED goes out, then
reconnect it to retrieve previous status code (if available). Repeat
as needed for more previous status codes.
3. Operate furnace through 1 heat cycle to test for proper
operation and check LED status.
4. If furnace is operating properly and continuously-lit LED
indicates proper operation, replace outer access door.
6
FIELD 24-VOLT WIRING
FIELD 115-, 208/230-, 460-VOLT WIRING
FACTORY 24-VOLT WIRING
FACTORY 115-VOLT WIRING
FIELD-SUPPLIED
FUSED DISCONNECT
208/230- OR
460-VOLT
THREE
PHASE
208/230-
VOLT
SINGLE
PHASE
GND
UNIT
A95236