Mitsubishi Electronics MSH-A18ND service manual How to check mis-wiring

Page 16

When OPERATION INDICATOR lamp flashes ON and OFF in every 0.5-second.

Outdoor unit doesn’t operate.

D How to check mis-wiring

w Short circuit of JPG and JPS on the indoor electronic control P.C. board enables self -check to be displayed in 3 seconds.

Start

Correct them.

Turn ON the power supply. (outdoor unit)

Press EMERGENCY OPERATION switch once.

After 3 minutes, mis-wiring is indicated (0.5-second ON, 0.5-second OFF) on OPERATION INDICATOR

lamp on indoor unit.w

Yes

Is this mis-wiring, poor contact,

 

 

or wire disconnection?

 

No

1.Turn OFF the power supply (outdoor unit) and disconnect indoor and outdoor connecting wire 3 on indoor side.

2.Short-circuit terminal block N-3by lead wire.

3.Turn ON the power supply (outdoor unit) and press EMERGENCY OPERATION switch once.

Is there 20V DC between both ends of

PS132 on the indoor electronic control P.C. No board ?

( By tester, the stylus is between 0 ~ 20V. )

Yes

Turn OFF the power supply. (outdoor unit)

Connect ON indoor/ outdoor connecting wire.

Replace the indoor electronic control P.C. board.

Turn ON the power supply. (outdoor unit)

Is there 5V DC between J205 + -J101 -

/ J101 + -J401 - on the deicer P.C. board?

Yes

During EMERGENCY OPERATION, is there 10V DC between both ends of R601 on the deicer P.C. board?

(By tester, the stylus is between 5 ~10V.)

Yes

No

Replace the deicer P.C. board.

 

 

 

 

 

 

 

 

No

Make the wiring between CN730

on the deicer P.C. board and

 

 

 

 

 

 

outdoor terminal block correct.

 

 

 

Replace the deicer P.C. board.

Refer to outdoor unit service manual.

16

Image 16
Contents Contents Revised EDITION-BAccessories Technical ChangesPart Names and Functions Indoor Unit MSH-A18ND MSH-A24NDRemote Controller MSH-A18ND MSH-A24ND Specification MSH-A18ND MSH-A24NDOutlines and Dimensions MSH-A18ND MSH-A24ND Indoor UnitMSH-A18ND Indoor Unit Wiring DiagramMSH-A24ND Indoor Unit Refrigerant System Diagram Service Functions MSH-A18ND MSH-A24NDHow to release Auto Restart Function Troubleshooting Take care of the following during servicingInstruction of troubleshooting Troubleshooting check table Trouble criterion of main parts Check of indoor fan motor Check of indoor electronic control P.C. board How to check mis-wiring Indoor electronic control P.C. board Disassembly Instructions MSH-A18ND MSH-A24ND Indoor Unit Operating Procedure PhotosOperating Procedure Photos Parts List non-RoHS compliant Accessory and Remote Controller AIR Cleaning Filter RoHS Parts List RoHS compliant Vane Motor Vertical AIR Cleaning Filter Page Page Made in Japan