Mitsubishi Electric CITY MULTI PUHY-400YMF-B, Service Handbook

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Classification Portion Check item Trouble
Transmission
line
System set
Before starting
Limitation of transmission line length followed? For
example, 200 m or less (total length: 500 m) at the farthest.
1.25 mm 2 or more transmission line used?
(Remote controller 10 m or less 0.75 mm 2 )
2-core cable used for transmission line?
Transmission line apart from power source line by 5 cm
or more?
One refrigerant system per transmission line?
The short circuit connector is changed form CN41 to
CN40 on the MAIN board when the system is centralized
control? (Just one outdoor unit. Not all outdoor units.)
No connection trouble in transmission line?
Address setting properly done? (Remote controller,
indoor unit and outdoor unit.)
Setting of address No. done when shutting off power
source?
Address numbers not duplicated?
Turned on SW3-8 on indoor unit circuit board when
mounting room thermistor sensor?
Refrigerant piping ball valve (Liquid pressure pipe, gas
pressure pipe, oil balance pipe) opened?
Turn on power source 12 hours before starting opera-
tions?
Erroneous operation, error stop.
Erroneous operation, error stop.
Error stop in case multiple-core
cable is used.
Erroneous operation, error stop.
Not operate.
Not operate.
Error stop or not operate.
Error stop or not operate.
Can not be properly set with power
source turned on.
Not operate.
Set temperature not obtained at heating
operations. (Thermostat stop is difficult.)
Error stop.
Error stop, compressor trouble.
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