32
period by solid GREEN for 1/5 to 5 seconds). The LED will flash up to five
stored fault codes, beginning with the most recent. If there are no fault
codes in memory, the LED will flash two green flashes. The control will
flash the most recent error first and the oldest error last (last in first out).
There shall be 2 seconds between codes. Solid LED error codes will not
be displayed.
9.5.7-
Fault code reset
To clear the fault code memory, push and hold the "LAST ERROR" button
for more than 5 seconds and less than 10 seconds. (Control will indicate
this period by RAPID GREEN FLASH for 5 seconds to 10 seconds.) The
LED will flash three green flashes when the memory has been cleared.
9.5.8-
Diagnostic features
The 50M51 control continuously monitors its own operation and the
operation of the system. If a failure occurs, the red LED on the control will
flash a failure code. If the failure is internal to the control, the light will stay
on. In this case, the entire control should be replaced, as the control is not
fielded repairable.
If the sensed failure is in the system (external to control), the LED will flash
in the following flash-pause sequences to indicate failure status (each
flash will last approximately 0.25 seconds, and each pause will last
approximately 2 seconds.)
During a second-stage error condition, the red LED when in lockout will
flash groups of double pulses. The red LED will flash on for approximately
1/15 second then off for 1/15 second then on for 1/15 second, then off for
3/10 second. The pause between groups of flashes is approximately 2
seconds. The diagnostics will indicate the specific fault through the
following codes:
9.6- OPTION SWITCH SETTINGS
– 2 STAGE
ECM
9.6.1-
Thermostat type and heat-fan-off delay
Table 19: DIP Switches
9.6.2-
Multi-stage thermostat set-up, factory default
DIP switches S7-1 and S7-
2 (see table above) are set to the “Off” position
from the factory for use with a multi-stage thermostat. This allows the
thermostat to control staging between low and high fire.
9.6.3-
Single stage thermostat set-up, module controls
staging
DIP switches, S7-1 and S7-2 (see table above) configure for a single stage
thermostat. Options include a 10 minutes delay on second stage, 20
minutes delay on second stage or an Auto setting allowing the module to
calculate the time delay for second stage based on average demand. The
“Average Calculated Duty Cycle” table shows how the module calculates
staging based on demand.
Table 20: Duty cycle
9.6.4-
Heat fan off delay timing
DIP switches S7-3 and S7-4 (see table above) configure the number of
seconds the blower will run after the call for heat ends. Factory default is
90 seconds.Heat pump and de-humidification
Table 21: DIP Switches
Heat pump systems
DIP switch S5-
1 (see table above) is set to “On” from the factory for use
with conventional (non-Heat Pump systems). For heat pump systems
move the S5-
1 DIP switch to the “Off” position. This will continuously
output an O signal to the motor whenever
there is Y signal and run the
circulator blower at a constant speed when the pump is operating.
9.6.5-
De-humidification connection
DIP switch S5-
2 (see table above) is set to “On” from the factory for
systems that do not have a dehumidification terminal connection from the
thermostat. For systems using a thermostat that provides a De-
Humidification option move DIP switch S5-
2 to “Off”.
9.6.6-
Normal operation
– heat on
When the thermostat calls for heat the module verifies the pressure
switches are open and energizes the inducer (high speed) and optional
humidifier contacts. When the low pressure switch contacts close a 15
second pre-purge begins. After 15 seconds the inducer switches to low
speed and the 120 VAC igniter is energized. The igniter warms up for 17
seconds and the gas valve is energized on low fire. Flame must be
detected within 4 seconds. If flame is detected, a 45 seconds heat, fan on
time delay begins. This allows the heat exchanger to warm up before
energizing the circulator on low speed and (optional) Electronic Air
Cleaner contact. When the thermostat (or module) initiates second stage
the inducer is energized at high speed.
This closes the second stage inducer pressure switch then energizes the
second stage on the gas valve and then the high heat circulator speed.
9.6.7-
Normal operation
– heat off
When the thermostat satisfies for second stage, the control will switch high
speed inducer and high fire gas valve to low speed inducer and low fire
gas valve. After the 30 seconds high heat fan delay the circulator will drop
to low speed. When the thermostat satisfies for first stage the gas valve
de-energizes and the inducer will run low speed for a 15 seconds post-
purge. The circulator runs until the heat off delay ends.
Note:
If the module is configured for a single stage thermostat and
running on second stage when the call for heat ends, the
circulator will drop to low speed after 30 seconds and continue
until the heat off delay ends.
Average
calculated
Duty Cycle
% Equals
or is less
than
Low to
High Stage
Delay
Demand
0
38
12 minutes
Light
38
50
10 minutes
Light to Average
50
62
7 minutes
Average
62
75
5 minutes
Average to Heavy
75
88
3 minutes
Heavy light
88
100
1 minute
Heavy
Summary of Contents for c105-1-d
Page 20: ...20 Figure 16 Wiring diagram One stage PSC ...
Page 21: ...21 Figure 17 Two Stage PSC Furnace Control ...
Page 22: ...22 Figure 18 Two Stage ECM Furnace Control ...
Page 26: ...26 Figure 21 Direct venting Figure 22 Multi venting ...
Page 37: ...37 Figure 25 Part list 1 Stage PSC ...
Page 38: ...38 Figure 26 Part list 1 Stage PSC continued ...
Page 41: ...41 Figure 27 Part list 2 Stage PSC ...
Page 42: ...42 Figure 28 Part list 2 stage PCS continued ...
Page 45: ...45 Figure 29 Part list X13 ...
Page 46: ...46 Figure 30 Part list X13 continued ...
Page 49: ...49 Figure 31 Part list 2 Stage ECM ...
Page 50: ...50 Figure 32 Part list 2 Stage ECM continued ...