Carrier 538FEQ009RBGA, Руководство по обслуживанию

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7. Diagnosis for overboard and discharge malfunction (AP1 below is control board of outdoor unit)
Main detection points:
S Is the electron expansion valve well connected? Is the expansion valve damaged?
S Is there a refrigerant leak?
S Is the overload protection damaged?
Malfunction diagnosis process:
Connect wire
wiring diagram
Replace EKV
coil of electronic
expansion valve
If the wiring terminal FA
is well connected?
Remove
malfunction?
The resistance value of
firs t 4 l e a d fo ot an d th e
fif th lead fo ot is similar,
less than 100
After the unit
de-energized
for 20min
Remove
malfunction?
Yes
No
No
No
Is the overload protector SAT
well connected?
No
Under ambient temperature, test the
resistance of overload protector
Yes
Yes
Replace
overload
protector SAT
No
Yes
Check refrigerant, if there is
leakage, please refer to unit
specification
Replace
control board
AP1
End
resistance value 1000
Fig. 43 – Troubleshooting