Klargester keeps tripping RCD

[Tony_Park]

Hi,

asking this question on the offchance that someone can shed some light on the problem.

We moved into our house about 2 months ago, the house is in the middle of nowhere, and has a Klargester Bio Disc unit installed in the garden, this has a water storage tank for clean water containing 2 pumps to push out the clean water into a nearby drainage ditch.

It appears that recently, the rcd trip switch has tripped and wasn't spotted, so the Klargester unit was rather full, and so was the water storage tank. On finding that these items weren't working, we reset the trip switch. All good so far, the Klargester inspection pit looking rather empty now, and same in the water storage tank.

However, we have a persistent problem, in that after resetting the trip switch, it will happen again, this could be seconds after resetting, or could be hours.

1) any ideas on what could be causing this problem?
2) what could be the resolution ?

We're about to book a service for the unit, since the only paperwork we have regarding a service is nearly 2 years old, and I suspect its overdue a service... but we'd like to understand more about potential causes for the above problems!

Thanks
Tony

 

[Amdobs]

Hi Tony - I know this is very old now but did you ever find the reason for the RCD tripping? We are having the same issue

 

[trojanhawrs]

If it's a RCD tripping (rather than mcb) it's likely the motor or the connections are getting wet, or the motor is on its way out.

Is it tripping immediately?

 

[Amdobs]

Yes - can’t even but the RCD switch back up (can only do this if I put the Klargeister switch down). We did have a new motor put in in December…

 

[trojanhawrs]

Does it have some kind of control box?

 

[Hugh Jaleak]

What electrical components have you got? Just the motor driving the Disc's, a control box as well for the unit and/or pump(s)?

 

[jj4091]

Does it have some kind of control box?

Or a junction box to join different cables ie armoured to Flexi.

 

[Amdobs]

We got an electrician out who thinks it may be the capacitor… ??

 

[Hugh Jaleak]

We got an electrician out who thinks it may be the capacitor… ??

I wouldn't want to argue, assuming they've tested everything, then it's quite possible. Would suspect the Capacitor is fitted to these things to help with the start up current, when the drive is restarted after power failure or switch off for servicing etc.

 

[trojanhawrs]

I'd suspect it'll be a start capacitor for a single phase motor. Failure would cause the motor to stall and trip on overcurrent. Would be surprised if that prevented the RCD from even switching back on.
I asked already, does the unit have a control box?

 

[bernardgreen]

The diagrams in http://www.klar-environment.com/pdf/PD0094-24BA-BB_Installation_Guidelines.pdf show the capacitor as a RUN capacitor. It's function is to create a phase shifted supply to the Z terminal of the motor. This phase shift ensures the motor rotates in the right direction.

A START capacitor is disconnected when the motor reaches the normal running speed.

If the capacitor has failed then the motor may stall and take a higher than normal current which could cause a MCB to operate on the over current.


If the RCD is tripping then there is a Earth fault which allows current to leak to Earth.

A failed capacitor can create an Earth fault if the case is Earthed and an internal short ciruit develops