Daikin APGM3 Service And Troubleshooting page 8

SYSTEM OPERATION
Terminal
230VAC Line 1 Input (x2)
230VAC Line 2 Input (x4)
Indoor Blower Heat Speed
Indoor Blower Cool Speed
Induced Drafter Blower Output
Unused/Motor Speed Park Terminals (x2)
Flame Sensor
Continuous Fan (G) / Economizer
Spark Igniter Output
Table 2: PCBAG123 Single Stage Control Terminal
Definitions
Period
Pre-Purge
Inter-Purge
Post Purge
Trial-for-Ignition (TFI)
Flame Stabilization Period
Heat ON Delay
Heat OFF Delay
Cool ON Delay
Cool OFF Delay
Ignition Attempts
Recycles Infinite
Automatic Restart
Compressor Short Cycle Delay
Table 3: PCBAG123 Single Stage Control Timings
System Status
Normal
Internal Fault/Gas Valve Fault
Ignition Lockout
Pressure Switch Stuck Closed
Pressure Switch Stuck Open
Open High Temperature Limit
Flame Detected with Gas Valve De-Energized
Compressor Short Cycle Delay Active
Table 4: PCBAG123 Single Stage Control LED
Status Codes
Label
L1
L2
HEAT
COOL
DI
UNUSED
FS
ECON
SPARK
Timing
15 Seconds
15 Seconds
29 Seconds
7 Seconds
10 Seconds
30 Seconds
Selectable 120, 135
or 150 Seconds
7 Seconds
60 Seconds
3 Attempts
4 Recycles
(5 Flame Losses)
60 Minutes
3 Minutes
LED Flashes
On
Off
1
2
3
4
5
6
PCBAG127 IGNITION CONTROL
SEQUENCE OF OPERATION (TWO STAGE
CONTROL)
Heating Operation: Low Stage Heat
1. Thermostat type is set to two-stage.
2. Thermostat "W1" input initiates low stage heating.
3. Induced draft blower is energized at high speed for
the pre-purge period. Pre-purge timer begins after
control recognizes pressure switch has closed.
4. Trial-for-ignition period begins after pre-purge period
expires. Low and high stage gas valves are energized
along with the igniter for trial-for-ignition period. Igniter
is de-energized when flame is detected.
5. Flame is achieved and detected during trial-for-ignition
period. Flame stabilization period begins when flame
is detected.
6. De-energize high stage gas valve and switch induced
draft blower to low speed within five seconds of flame
detection.
7. Air circulating blower is energized at low heat speed
after heat ON delay time expires. Heat ON delay timer
begins when flame is detected.
8. Control monitors thermostat, flame, limit, and pressure
switch inputs during low stage heating.
9. Thermostat "W1" input is removed.
10. Low stage gas valve is de-energized.
11. Induced draft blower remains energized at low speed
for post purge period.
12. Air circulating blower remains energized at low heat
speed for heat OFF delay. Heat OFF delay begins
when "W1" input is removed.
13. Control returns to Standby and awaits next thermostat
request.
Heating Operation: High Stage Heat
1. Thermostat type is set to two-stage.
2. Thermostat "W1" and "W2" inputs initiate high stage
heating.
3. Induced draft blower is energized at high speed for
the pre-purge period. Pre-purge timer begins after
control recognizes pressure switch has closed.
4. Trial-for-ignition period begins after pre-purge period
expires. Low and high stage gas valves are energized
along with the igniter for trial-for-ignition period. Igniter
is de-energized when flame is detected.
5. Flame is achieved and detected during trial-for-ignition
period. Flame stabilization period begins when flame
is detected.
6. Gas valve and induced draft blower remain at high
stage and high speed.
7. Air circulating blower is energized at high heat speed
after heat ON delay time expires. Heat ON delay timer
begins when flame is detected.
8. Control monitors thermostat, flame, limit, and pressure
switch inputs during high stage heating.
9. Thermostat "W1" and "W2" inputs are removed.
10. High and low stage gas valves are de-energized.
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