Checking Transformer And Control Circuit; Checking Contactor And/Or Relays - Daikin APGM3 Service And Troubleshooting

SERVICING
Two-Stage Heating (timed) and Two-Stage Cooling
(timed) with Single Stage Thermostat Diagram
Line voltage now present.
With power ON, thermostat calling for cooling:
1. Use a voltmeter to check for 24 volts at thermostat
wires C and Y in the condensing unit control panel.
2. No voltage indicates trouble in the thermostat, wiring
or external transformer source.
3. Check the continuity of the thermostat and wiring.
Repair or replace as necessary.
Indoor Blower Motor
With power ON:
Line voltage now present.
1. Set fan selector switch at thermostat to "ON" position.
2. With voltmeter, check for 24 volts at wires C and G.
3. No voltage indicates the trouble is in the thermostat or
wiring.
4. Check the continuity of the thermostat and wiring.
Repair or replace as necessary.

Checking Transformer and Control Circuit

High Voltage!
Disconnect all power before servicing or
installing. Multiple power sources may be
present. Failure to do so may cause property
damage, personal injury or death.
5 MINUTE DELAY
PERIOD WITH
JUMPER IN THIS
POSITION
10 MINUTE DELAY
PERIOD WITH
JUMPER IN THIS
POSITION
WARNING
WARNING
WARNING
A step-down transformer (208/240 volt primary to 24 volt
secondary) is provided with each unit. This allows ample
capacity for use with resistance heaters. The outdoor
sections do not contain a transformer.
Disconnect ALL power before servicing.
1. Remove control panel cover, or etc., to gain access to
transformer.
With power ON:
Line voltage now present.
2. Using a voltmeter, check voltage across secondary
voltage side of transformer (R to C).
3. No voltage indicates faulty transformer, bad wiring, or
bad splices.
4. Check transformer primary voltage at incoming line
voltage connections and/or splices.
5. If line voltage available at primary voltage side of
transformer and wiring and splices good, transformer
is inoperative. Replace.

Checking Contactor and/or Relays

High Voltage!
Disconnect all power before servicing or
installing. Multiple power sources may be
present. Failure to do so may cause property
damage, personal injury or death.
WARNING
WARNING
WARNING
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