leakage

[i=p/u]

got a call on Saturday to say the newish washing machine is blowing the trip. when i had nosey around swapping leads and whatever i tried still tripping when starts a cycle.

its a tt installation with a ze of 14 ohms , insulation resistance of machine was as follows
l-e 1.3 M/ohms
n-e 12 M/ohms

earth continuity from plug to metal part of machine was 1.6 ohms

what i thought was an rcd is actual a voltage measuring device, apparently were installed before rcd came about , had no rating on it but has a yellow test button.

what else can i try or if i ring an appliance engineer what will he tell me. or what will he do.

thanks if your full of knowhow. im all ear or eyes

 

[telectrix]

start by replacing that VOELCB with a RCD. then take it from there.

 

[StuSpiers]

Voltage trips have been unfit for continued service for some time.

It actually mentions them in document P (page 36).

 

[AndyL]

Agree with Tel, also 1.6 ohms is too high for your CPC continuity, should be a maximum of 0.1 ohm

 

[i=p/u]

only get as far as page 3 all time..

.. need to clamp meter to measure earth leakage then can change device accordingly ..with a ze of 14 ohm i can get away 100mA - 500mA

would these devices be more sensitive than rcds?? id say no. but can somone explain how they work

 

[Engineer54]

As they are voltage operated why would you clamp test the device??

 

[i=p/u]

just the earth before i INSTALL A 100ma RCD JUST IN CASE THERE 120Ma FLOWING...

 

[telectrix]

you should be installing a 30mA RCD anyway. but, yes, by all means check installation leakage or global IR test before fitting RCD or you might end up spending an extra day sorting out problems which you haven't allowed for in your quote.

 

[StuSpiers]

only get as far as page 3 all time..

.. need to clamp meter to measure earth leakage then can change device accordingly ..with a ze of 14 ohm i can get away 100mA - 500mA

would these devices be more sensitive than rcds?? id say no. but can somone explain how they work

Well if there is a Voltage trip chances the fuseboard isn't 17th compliant?
If I were you I would be giving the customer two choices - direct replacement with 30ma rcd (not recommended)
Fuse board upgrade.
then fix any problems like washing machines.

Voltage trips operate when the touch voltage rises above 50V (unless I'm mistaken)
but are unreliable due to parallel paths making them inoperative.

 

[Engineer54]

just the earth before i INSTALL A 100ma RCD JUST IN CASE THERE 120Ma FLOWING...

I'd be more inclined to find out exactly WHY there was 120mA flowing in a domestic installation!!....lol!!!