Carrier WEATHERMASTER 48/50Z030-105 Operation And Service Manual page 60

Heat 1
STAGE
MBB-RLY8
IGC1
0 OFF
1 ON
2 ON
3 ON
4 ON
5 ON
Heat 1
STAGE
MBB-RLY8
IGC1
0 OFF
1 ON
2 ON
3 ON
4 ON
5 ON
6 ON
7 ON
8 ON
9 ON
Table 51 — IGC LED Indicators
ERROR CODE
Normal Operation
Hardware Failure
Fan On/Off Delay Modified
Limit Switch Fault
Fame Sense Fault
Five Consecutive Limit Switch Faults
Ignition Lockout Fault
Ignition Switch Fault
Rollout Switch Fault
Internal Control Fault
Software Lockout
NOTES:
1. There is a 3-second pause between error code displays.
2. If more than one error code exists, all applicable error codes will
be displayed in numerical sequence.
3. Error codes on the IGC will be lost if power to the unit is
interrupted.
RELOCATE SAT FOR HEATING-LINKAGE APPLICA-
TIONS — If Configuration
the supply air temperature thermistor (Temperatures
→
SAT) must be relocated downstream of the installed heating
device. This only applies to two-stage gas or electric heating
→
types (Configuration HEAT
Determine a location in the supply duct that will provide a
fairly uniform airflow. Typically this would be a minimum of
Table 49 — Staged Gas Heat Control Steps (HT.ST = 1)
Heat 2 Heat 3
MBB-RLY7 SCB-RLY1
MGV1 IGC2
OFF OFF
OFF OFF
ON OFF
OFF
ON
ON
Table 50 — Staged Gas Heat Control Steps (HT.ST = 3)
Heat 2 Heat 3
MBB-RLY7 SCB-RLY1
MGV1 IGC2
OFF OFF
OFF OFF
ON OFF
OFF
ON
ON
OFF
OFF
ON
ON
LED INDICATION
On
Off
1 Flash
2 Flashes
3 Flashes
4 Flashes
5 Flashes
6 Flashes
7 Flashes
8 Flashes
9 Flashes
→ →
HEAT LAT.M is set to YES,
→
AIR.T
→
HT.CF=1 or 2).
RELAY OUTPUT
Heat 4
SCB-RLY2
MGV2
OFF
OFF
OFF
ON OFF
ON OFF
ON ON
RELAY OUTPUT
Heat 4
SCB-RLY2
MGV2
OFF
OFF
OFF
ON OFF
ON OFF
ON ON
ON OFF
ON ON
ON ON
ON ON
5 equivalent duct diameters downstream of the unit. Also, care
should be taken to avoid placing the thermistor within a direct
line-of-sight of the heating element to avoid radiant effects.
Run a new two-wire conductor cable from the control box
through the low voltage conduit into the space inside the build-
ing and route the cable to the new sensor location.
Installing a New Sensor — Procure a duct-mount temperature
sensor (Carrier P/N 33ZCSENPAT or equivalent 10-kilo-ohm
at 25C NTC [negative temperature coefficient] sensor). Install
the sensor through the side wall of the duct and secure.
Re-Using the Factory SAT Sensor — The factory sensor is
attached to the left-hand side of the supply fan housing. Dis-
connect the sensor from the factory harness. Fabricate a mount-
ing method to insert the sensor through the duct wall and se-
cure in place.
Attach the new conductor cable to the sensor leads and ter-
minate in an appropriate junction box. Connect the opposite
end inside the unit control box at the factory leads from MBB
J8 terminals 11 and 12 (PNK) leads. Secure the unattached
PNK leads from the factory harness to ensure no accidental
contact with other terminals inside the control box.
TEMPERING MODE — In a vent or cooling mode, the
economizer at minimum position may send extremely cold
outside air down the ductwork of the building. Therefore it
may be necessary to bring heat on to counter-effect this low
supply-air temperature. This is referred to as the tempering
mode.
60
Heat 5 Heat 6
SCB-RLY3 SCB-RLY4
IGC3 MGV3
OFF OFF
OFF OFF
OFF OFF
OFF OFF
OFF OFF
OFF OFF
Heat 5 Heat 6
SCB-RLY3 SCB-RLY4
IGC3 MGV3
OFF OFF
OFF OFF
OFF OFF
OFF OFF
OFF OFF
OFF OFF
ON OFF
ON OFF
ON OFF
ON ON
CAPACITY
%
0
37
50
75
87
100
CAPACITY
%
0
25
33
50
58
67
75
83
92
100