MCB tripping intermittently

[Buck Taylor]

Yes, so once it's stalled (buzzing) it's going to trip, presuming you mean while it's buzzing.

Does it still work when other taps are opened from an off state?

Yeah when buzzing and opening up another tap it trips the MCB.
Not sure what you mean about opening another tap from an off state?
The MCB has never tripped from opening any other tap in the house!

 

[Mark K]

Yeah when buzzing and opening up another tap it trips the MCB.
Not sure what you mean about opening another tap from an off state?
The MCB has never tripped from opening any other tap in the house!

I mean what you said..no other tap opening trips it.

As Chuck said it sounds like a motor and/or capacitor failing. The characteristics of the kitchen tap cause a higher current draw, which causes the breakdown and the motor stalls and won't start. Opening other taps doesn't cause the initial current draw, and hence heat, so the motor gets going.

I bet you can open the kitchen tap no problem if another tap is already running?

 

[Buck Taylor]

I mean what you said..no other tap opening trips it.

As Chuck said it sounds like a motor and/or capacitor failing. The characteristics of the kitchen tap cause a higher current draw, which causes the breakdown and the motor stalls and won't start. Opening other taps doesn't cause the initial current draw, and hence heat, so the motor gets going.

I bet you can open the kitchen tap no problem if another tap is already running?

Yeah opening the kitchen tap whilst the pump is running does not trip the MCB. Looked on
showerdoc.com for a replacement starting capacitor and it is sold out!!! Oh the joys I'll look for something compatible.

 

[Buck Taylor]

I mean what you said..no other tap opening trips it.

As Chuck said it sounds like a motor and/or capacitor failing. The characteristics of the kitchen tap cause a higher current draw, which causes the breakdown and the motor stalls and won't start. Opening other taps doesn't cause the initial current draw, and hence heat, so the motor gets going.

I bet you can open the kitchen tap no problem if another tap is already running?

Good morning gents,
The first time this has happened..... The tap in the downstairs toilet has now tripped the MCB, so does that now point more to the start capacitor?

 

[marvoni]

Do you have access to a clamp meter?



If you can beg, borrow or steal one for a few hours it will give you a definative answer.

It's a non-contact tester that measures current but you need to isolate the power whilst you clamp it around either the live wire or a neutral wire of the cable that supplies the pump.

If at any time the current being drawn by the pump exceeds the manufacturers stated maximum current you should replace the pump.

You could try replacing the capacitor but it's a long shot. Capacitor damage is visible in the majority of cases manifesting as a swolen or cracked casing or as burned terminations or other signs or arcing / overheating. Also, if the capacitor is faulty there's a high liklihood it was damaged due to another problem within the pump that caused high peak current or prolonged marginal over-current through it such as mechanical wear, bearing failure or scale build-up so it's more often than not a symptom rather than a root cause.

 

[Buck Taylor]

Gents, many thanks for all your input regarding the MCB tripping intermittently. I m sure to have rectified the cause, which does not make sense.

The inlet strainer on the hot side was very badly blocked with debris, so not sure why the pump didn't trip from all other outlets?
Confused??? Me too, happy days!
Thanks again