Extension lead to shed from outdoor socket

[frembrit]

Hi all,

Just moved in to a new house which has had an outdoor socket fitted.

Firstly, it's the type that cannot close when a plug is plugged in. Can I change it for one that has a cover that will close when a plug is fitted?

Secondly, am I allowed to run an extension cable from that to my shed when I need to, and leave it in over night? (8 metres away) It's to power the battery charger for the motorbike. Will I also need an extension cable with a waterproof socket too or just use a normal one?

Thanks in advance.

 

[EFLImpudence]

Can I change it for one that has a cover that will close when a plug is fitted?

Yes, if you are competent. Make sure you have RCD protection in your consumer unit. Outdoor socket wouldn't be fitted today witout one but who knows when it was and by whom.

Secondly, am I allowed to run an extension cable from that to my shed when I need to, and leave it in over night? (8 metres away)

It's your house - but only if RCD as above (for safety).

Will I also need an extension cable with a waterproof socket too or just use a normal one?

No, not if it's in the shed and won't get wet but get a good sturdy lead.

 

[ericmark]

Portable equipment does not come under LABC but if you fix the cable even if only plugged in then it does.

There is no regulation to say you should not do as you list. However as already stated using a RCD will make it safer.

You can get 10ma as well as 30ma RCD's and you may want to use a 10ma so a fault on the extension lead will not trip whole house.

In the main it is all common sense extension leads are only dangerous if used without normal care. Look at any caravan site and you will see loads of extension leads each feed from a RCD and there are very few problems.

 

[Taylortwocities]

You can get 10ma as well as 30ma RCD's and you may want to use a 10ma so a fault on the extension lead will not trip whole house.

Not quite, old friend. And I regret having to pick you up on this.

In the case that you state it is true that a an earth fault of (nominally) greater than 10mA and less than 30mA will cause the 10mA RCD to trip.

However

Lets suppose there is an earth fault of more than 30mA (and most of them are). In that case the RCD that trips could be either RCD. It'll be the one with the faster trip time, or the one that's characteristic most suits the point on the sinewave that the fault occurs.

To provide discrimination of RCDs you have to use time as the factor, not trip current. That is why time delay (S Type) RCDs are used in RCD discrimination applications.

 

[ericmark]

Taylortwocities is of course correct I have seen where a 30ma, 100ma, 1A, and 2A RCD all tripped when a worker put a nail through the cable to hang up his coat in the canteen. And both the 1 and 2 amp had time delays and the delay was greater with 2 amp.

Yes I know the 1A and 2A should not have tripped but in practice they did.

However damp and dust tends to build up and the leakage to earth is not sudden as with the nail and then the 10ma trip will tend to go first stopping the whole house tripping.

I have seen where a metal clad 10ma would trip the 100ma RCBO on the main board when the test button was pressed. There seems to be exceptions to every rule.

However with extension lead supplies to caravans it is required to fit two RCD's of same size on same supply one in caravan and other in supply oddly with no discrimination between them.

It could be argued that 30ma is minimum size and to comply with regulations double pole RCBO's of 10ma should be used in the caravan. However if you try to buy a double pole consumer unit and double pole 10ma RCBO's then you will see why this is not done. Many times for split phase 110 volt supplies I have tried to buy double pole consumer units or distribution boards and have failed having to fit three phase boards instead.

Theory and practice are different.

 

[frembrit]

Can I change it for one that has a cover that will close when a plug is fitted?

Yes, if you are competent. Make sure you have RCD protection in your consumer unit. Outdoor socket wouldn't be fitted today witout one but who knows when it was and by whom.

Secondly, am I allowed to run an extension cable from that to my shed when I need to, and leave it in over night? (8 metres away)

It's your house - but only if RCD as above (for safety).

Yes, competent to change it.

It's a brand new house and the external socket is spurred from an indoor socket which are all protected in the consumer unit.

From the other posts, if I understand correctly, using a socket with a built in RCD may not stop the main one from tripping too?

Thanks.

 

[Taylortwocities]

From the other posts, if I understand correctly, using a socket with a built in RCD may not stop the main one from tripping too?

Thanks.

Eaxctly, It could be the RCD in the socket that trips, or the house RCD, or both!

 

[frembrit]

So I may as well buy a socket without the RCD as it's cheaper.

Thanks.

 

[ban-all-sheds]

A great deal cheaper in the case of MK Masterseal ones...