Explaining RCD's to customers, (domestic)

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Senario:-

done a domestic rewire or CU replacement.

customer now has split load board with RCD fitted.

you explain the new board, identifying MCB's main switch & RCD to customer.

and you want to show them what happens when a genuine earth fault occours, how to reset the RCD.

NOTE:-

RCDs such as MK when fault trip sit in a half-way position not all the way down as when press T button.

You can put your tester on to a circuit, but than can all look a bit to technical for the customer.

RCD deliberate fault inducer:-

13a plug short bit of flex batten lampholder 15w pygmy bulb

wire batten lamp holder accross 'live' & 'earth' at plug

(this will put a earth fault approx 60ma)

Plug lamp into suitable RCD protrected circuit.

Tell customer to watch CU,

Switch on lamp... RCD trips....leave lamp plugged in!

Try reseting RCD customer sees it re trip cause fault still on.

Go along switch off all RCD potected MCB's

Reset RCD,

Go along each MCB in turn until RCD trips again.

Explain to customer this is the faulty circuit and to leave that MCB off whilst re energise all other circuits & RCD.

Tell customer to go round all outlets on faulty circuit unpugging appliances checking for faulty accessories. etc..

Some customers suss this out quite quick when you show it as a proper simulated fault.

for others it can be a good memory jog exercise when they ring you up 4months later because the kettle or steam iron has tripped the RCD!

you are not explaining from scratch over the phone... just remind them

"do you remember when we switched all the curcuits off and rest them one at a time?"

It has helped me quite often to do some quick "remote diagnostics" over the phone.

Other Problems it helps:-

MK type RCDs which trip to mid position and have to be reset manualy fully off before they can be put on.

I have had customer ring up saying they cant reset the RCD its just loose in the middle wont stay up.

As the RCD is much stiffer than an MCB I have had a customer (elderly genteman) say the RCD was jammed and couldn't reset.

When they have seen it trip & reset it a few times they know what they are doing more easily..

Whereas if they have never reset the RCD it can sometimesbe a bit of a stumbling block.

The pygmy bulb is also very good when replacing old non-RCD Cu's

before your take the old board off, show the customer that your bulb (wired to earth) works ok on the old CU. Then after with new CU they can see that appliances or extension leads could be faulty even though they

"worked alright on the old fusebox!"

Also the lamp and plug fit nice in a medium size Jiffy-bag in your toolbox,

ready for use but protected from breaking the bulb!

arghhh me fingers are worn! :( my beers all drunk! :_| not time for bed!!

Well

 

MR DIAZ

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Nice little touch that, showing the client a simulated fault.

I

 

MR DIAZ

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As i said nice touch,

I worked out the benefits straight away.

You can also send the lad home early as the client resets for you ]:)

Win / win situation, Thanks B)

 

wally

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A good post SL, I like the pigmy lamp idea. Im often helping callers over the phone regarding RCDs but doing myself down on a job sometimes I think

 
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A good post SL, I like the pigmy lamp idea. Im often helping callers over the phone regarding RCDs but doing myself down on a job sometimes I think
I have been using this method for a few years now...

gives the customer loads of confidence,

especially more elderly folks,

cuz they dont like change much anyway.. :|

for some reason the customer can understand that your lamp could be a faulty appliance easier than you 'magic tester box'?

Bulb and plug easier for the oldies to get thier head around.. :D

Strange.... But true! ?:|

and if they can see it do it and use it while youre there....

it is so much easier.

I reckon with 17th comming along it will be a very cheep and useful bit of kit for any spark to keep in their toolbox.

 

extension15

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I suppose, plugging your test meter in (RCD test), does something very similar?

:D ] :)

 
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I suppose, plugging your test meter in (RCD test), does something very similar? :D ] :)
Yes partially...

But the thing that the RCD tester dosn't do is leave a fault permanently On.

so the customer can have a go at resetting the RCD and watch it just drop back down again until you clear it.

The real world fault can often be a faulty appliance that they need to go and unplug before it will reset the RCD.

 

The Godfather

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Yes partially... But the thing that the RCD tester dosn't do is leave a fault permanently On.

so the customer can have a go at resetting the RCD and watch it just drop back down again until you clear it.

The real world fault can often be a faulty appliance that they need to go and uplug before it well reset RCD.
And equally you can try and blind the uneducated with science they don't understand, try as you will.

So perhaps best left alone.

Don

 

extension15

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Perhaps the RCD is possibly best expalined as the difference between 'life and death' when there is a fault as a result of an accident...

; \

 

baldelectrician

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I usually refer to RCD's as these powerbreaker things you get for lawnmowers, except this one does the half the 'fuse box'

I find an easy way to explain a RCD is to compare it to a radiator. The RCD trips when there is more going in than what is coming out.

If you had a 'leak' on a RCD circuit the power would trip.

If the same thing were compared to a radiatior the fault would be a puddle on the floor and there would be more going in as there is coming out

I explain that if, for example the kettle was on there would be around 10A goung up the live and 10A coming down the neutral, if there were 10A going up the live and 9.9 A back through the neutral the RCD would trip.

 
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300TDI

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I have a sheet explaining rcds that i leave with the customer

If anyone wants it let me know your e mail

 

Admin1

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You could PM a copy to me and I could put a link to it as a printable "pic" in my PhotoBucket, if you wish? and put the link on here.

 

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