Rdc problem

[Gary174]

Hi can anyone help I have two questions.
First is I have an rcd main switch consumers units with five ways on it and one of them is spare. Can I fit a cooker supply to it and question two is I checked the test switch the other day just because I haven't tested it for a long time. The rdc tripped as it should but when I tried to turn it back on it wouldn't reset. After trying for a while it eventually reset. I tried the test switch a few more times and occasionally it did the same thing. Do you think the rcd is u.s????

 

[flameport]

Cooker supply - maybe?
are parts still available for it / is this the only CU / what is the total load of the existing circuits / max load for the consumer unit / and so on

Reset - some do that. Others do not. Doesn't mean it is broken. Doesn't mean it is working properly either.

 

[ericmark]

1. Can I fit a cooker supply.
To add a circuit required LABC involvement which is either by using a registered electrician or by paying the LABC an absorbent fee. So although in theory the answer maybe yes, in real terms likely cheaper not to DIY.

2. Do you think the rcd is u.s????
Likely no. It is common for older RCD's to require one to turn off the MCB's before resetting. However there are two problems giving an answer here.
A) There are two common RCD's. The typical 100ma used with TT supplies. These only protect from fire and don't often trip. If this type then I would be worried. The second is a 30ma unit designed to protect personnel. These would not normally protect the whole house and the problem you are getting would be understandable.
B) To test a RCD one has to use a special meter which does not only test the current needed to trip it but also measures the time. The test button is only to test the mechanics of the device and does not do a full test.

The problem is many cookers use mineral insulated elements which are prone to absorb moisture and so often trip the 30ma RCD. So to add a cooker circuit is likely to make the problem worse. If it is a 30ma RCD then often we use RCBO's which is a MCB and RCD in one device. As the leakage is then not cumulative from all circuits they are less likely to trip and also if they do trip you only lose on circuit.

Returning to the "Can I" question the real question is:-
1) Have you the skill.
2) Have you the test equipment.

If you don't have the test equipment likely hire cost is £75 so add that to LABC charges you are looking at £200+ in charges before you guy anything to do the job with. So likely just not worth the cost and hassle to DIY.

 

[Gary174]

Many thanks for your replys