RCCB tripping on operating AC

vyral_143

vyral_143

Jarvis
Staff member
Super Mod
I have Siemens 5SM 1314-0 RCCB installed in my house. This was done by previous owner and we are using same. We have two ACs in house. In April-May, we used to run both of them but now only one was being operated. Recently (~in last 20 days), whenever I start one of AC, it would trip in some time. Time between starting of AC and tripping is highly variable. One day it would trip within 10-15 mins, some day in an hour or two and some other day it would go easily a night.

However due to this behavior, we have stopped using AC. Post this it have tripped only once. I have very noob question here as what exactly is issue ? I know that RCCB would trip when current mismatches; but not sure what thing needs to be checked ? Is it AC or is it input voltage or something else ?

Please note that I have all wiring done concealed and it is done by previous owner.
 
Not an expert but just my thought.
If it was the input voltage then the other AC would trip randomly.
Some UPS in your house would make the clicking sound if the input voltage was variable.

1) Try servicing the AC
2) It might be the wiring inside the concealed fitting to the AC. (Came across a case recently where during renovation and painting the concealed wiring pipe got leaked and that caused the wires to heat up and trip that room randomly).
 
RCCBs are quite sensitive - 30mA sensitivity in this case. Power electronics in the AC could be filtering line noise to the ground which would easily trip that.
If this RCCB is only connected to the AC, the easiest option would be to swap it out for an MCB. Do cross check that there aren't any other significant earth leaks in your AC.
 
Simply replace the particular MCB with a more Ampere MCB. Check on the mcb it should be saying like C15, C20 and soo on..Just goto any electrical store and get an MCB with more amperes like if you currently have C15 or 15A MCB, change it with C25 or 25A.
 
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