Sanyo THX1252 用户手册

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 CT circuit failure

Alarm meaning

Compressor 2 CT sensor (CT2) disconnected or short-circuit; Compressor 3 CT sensor (CT3) 
disconnected or short-circuit.

Alarm conditions

The current is still 1.5 A or less when 2 seconds or longer has elapsed after output from that 
compressor started.
* No current is detected even though the compressor is operating.

Probable cause

(1) CT circuit failure (including cut wiring, etc.)
(2) Disconnected CT circuit connector
(3) Missing phase where CT circuit is connected
(4) This CT circuit is connected to the connector of other CT circuit.
(5) PCB failure

Check

(1) CT circuit failure, PCB failure

Trouble: • Current value during compressor operation is below the threshold value.
Check:

 • Check that the connector is not disconnected.
 • Check the continuity of the CT circuit.
 • Install a normal CT in place of this CT  and check. If current is detected, then the 

PCB can be judged OK.

 • Check that current is flowing in the phase where the CT circuit is connected.

 

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Check voltage and current.

(2) Crossed wiring or installation error

Trouble:

When the compressor is stopped, the current value at the other compressor is high.

 When this type of condition occurs, seizing-detection control takes priority.

Correction

(1) Replace the CT circuit.
(2) Replace the outdoor unit PCB.
(3) Correct the problem.

Example

(1) The connector was not inserted after the PCB was replaced.

Notes

Use a normal CT as a tool to determine whether the trouble is a PCB failure or CT failure.

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Alarm meaning

Compressor 1 discharge temperature sensor (DISCH1) disconnected; Compressor 2 discharge 
temperature sensor (DISCH2) disconnected; Compressor 3 discharge temperature sensor 
(DISCH3) disconnected

Alarm conditions

• This alarm occurs when the discharge sensor temperature detector is not inserted into the tube’s

sensor holder, or when the sensor itself has suffered some kind of malfunction other than a cut
wire.

• When outdoor air temperature is 32°F (0°C) or higher:

Alarm occurs if the temperature detected by the discharge sensor has changed by less than

4 deg. when the compressor has operated for 10 minutes immediately after start.

• When outdoor air temperature is below 32°F (0°C):

Alarm occurs if the temperature detected by the discharge sensor has changed by less than
4 deg. when the compressor has operated for 30 minutes immediately after start.

Probable cause

(1) Discharge sensor temperature detector is not inserted into the tube’s sensor holder.
(2) Discharge sensor itself has suffered some kind of malfunction other than a cut wire.

Check

(1) Check that the discharge temperature sensor is inserted into the sensor holder.
(2) Check that sufficient heat-conducting putty is applied.
(3) Remove the discharge sensor from the sensor holder and expose the sensor to the outside

air for approximately 5 minutes. Check that the temperature detected by the sensor changes
to match the outside air temperature. (However the sensor cannot detect temperatures at or
below 32°F (0°C).)

Correction

(1) Install the sensor into the holder, and apply sufficient heat-conducting putty.
(2) If the sensor is malfunctioning, replace it.

Example
Notes

The discharge temperature sensor is generally a sensor intended for accurate detection of high

—

temperatures. Therefore, it will not accurately detect the temperature if the temperature at the
measurement point is 68°F (20°C) or below.

SM830157_W-2WAY_ECO-i.indb   15

SM830157_W-2WAY_ECO-i.indb   15

2007/06/08   14:23:46

2007/06/08   14:23:46