Electrickery and RCD's

[sandsnakes]

Hi guys,

question, how do you make an RCD less sensative. Had new consumer unit fitted with new wiring, dam thing goes pop every time you add a new appliance. Checked everything no wiring faults, lose leads etc, etc, then it will be ok for 2/4 hours and the heating kicks in whammo. Wait a while it settles down etc Now its the RCD that blows ont the fuse, this is on the up stairs ring main.

If I could I would go back to a none RCH based unit and just have an individual RCD on the electric shower.

Confused of London, wish I was in the bloody woods!


Sandsnakes

 

[Mikey P]

Could be your house earth that's got a bit too much impedance to ground - makes RCDs over-active.

Could be type of RCD itself but I'm assuming that the RCD is rated correctly for the ring.
Some RCDs are extremely quick to trip and would mean less damage to you if you put your finger in a socket; however, not sure what legal requirement is for trip time.

 

[sandsnakes]

Thanks mike I now inforn that is is the MCB which comes in two grades of sensitivity, sounds like a plan.

Sandnakes

 

[cub88]

If i remembercorrectly the RCD should trip below 0.4 seconds, how old is the installation and do you have any other ring mains on the same rcd where you could try the appliances and see if it holds?

 

[sandbender]

Different brands can perform differently, look for one of the better manufacturers ABB or Crabtree for instance, if it still trips get a better electrician in.

 

[topknot]

What you got fitted are RCBO'S to the new reg's if you change them for the old one's and have a problem you are leaviing yourself open. Yes they are sensative but we got to live with it .
Cheers Topknot

 

[IanM]

I assume you meen a RCD and not a circuit breaker ( the RCD will have a test button, the CB won't). The RCD will be marked with its sensitivity something like 30mA (milliamps) or 100mA. A number are available, the lower the more sensitive and the better the protection. Sometimes RCDs are affected by lightning or big electric motors in the circuit and people move up a little to avoid nuisance cuts but at the price of lower protection.

It sounds like you have a problem on that upstairs circuit. Try swapping the upstairs and downstairs RCDs and see if it is the RCD or the circuit that is of fault (I bet it is the circuit) but if you can't do that easily without rewiring you are in the hands of a professional with the correct equipment to chase down the problem.

 

[topknot]

Is this the type fitted.

 

[Stingray]

Ah.61009.Should have a blue neutral flylead now though.
You say that your upstairs ring is tripping.This points to an RCBO rather than a standard split load board.
If it's an rcbo protecting one ringmain the chances of overcurrent tripping is unlikely.Usually the electrician would use a type b breaker which would cope with most household loads.
Chances are that you have a loose neutral somewhere on the circuit.
Split load board with one RCD protecting multiple circuits,narrow it down (which you seem to have done).try the same appliances on the downstairs ring to see if they are at fault.
A neutral fault involving an rcd will usually show itself under load.

 

[Scots_Charles_River]

********deleted to avoid any accidents***********

Nick

 

[Stingray]

This is getting scary.
I'm an NICEIC test veryfier.PM me and I'll see if I can help.
Cheers

 

[Scots_Charles_River]

Stingray your right, maybe better .........

Nick

 

[topknot]

Yes Stringray , the rcbo is a old one but i keep it on the van for call outs . As you now there are to many RULES now and i would not want to put my name to it as the lost person to touch it, well.

 

[Stingray]

Yes Stringray , the rcbo is a old one but i keep it on the van for call outs . As you now there are to many RULES now and i would not want to put my name to it as the lost person to touch it, well.

The 17th is a nightmare for us all.
Trying to give realistic reasoning for the regs is a saga that would keep any author very rich.....

 

[John Fenna]

You know what?
I dont understand a word of this thread!

 

[hiho]

You know what?
I dont understand a word of this thread!

that makes two of us john

 

[Belfastman1958]

John....sorry mate, It's all electrician-speak stuff.

Stingray......once the 16th Ed started to go astray with their testing and earthing changes I just left it and took up a new career. Still miss working with the basic stuff, but certainly don't miss all the changes.

Alan.

 

[korvin karbon]

The 16th edition was the beginning of a secret push to move everybody into bushcraft

I am not a fully trained sparky but know a decent amount as my work involves it time to time, the offer was given to me in my youth and there is a part of me that is glad that i never took it.

Far to much regulation to keep people justifying their existence IMHO

 

[topknot]

John mate, Basically it means NO MORE DIY on the HOME ELECTRICS without a
PART P cert to go in your home pack. I think Stringray will agree with me on that.
Cheers Topknot.

 

[Stingray]

John mate, Basically it means NO MORE DIY on the HOME ELECTRICS without a
PART P cert to go in your home pack. I think Stringray will agree with me on that.
Cheers Topknot.

Quite right.People forget that they do a bit of DIY which works well (so will a bit of wet string ).Then they move house and leave a potential death trap laying in wait for some unsuspecting householder.
Mind you....you should see some of the interesting wiring in my house.But then again I know what I can get away with )