Bit of an argument at work - anyone settle?

[securespark]

Disconnection times......

Immersion - 5s

Lighting - 5s

Exterior lighting - 5s

Boiler - 5s

Doorbell - 5s

Shower - 0.4s

Cooker - 5s (with s/o - 0.4s)

Socket outlets - 0.4s

Agree or disagree??

 

[RF Lighting]

A shower is fixed equipment, so should it not have 5 seconds disconnection time? (working on the theory that RCD is only a manufacturers recommendation?)

 

[DESL]

My understanding is anything supplying portable equipment is 0.4s

Fixed equipment 5s

So only question is shower?

 

[DESL]

RF beat me to it

 

[festa]

Personally, if I was fitting Class 1 lighting outside I would make it 0.4 second disconnection time.

 

[RF Lighting]

Slight hijack here, but should a dedicated external socket be 0.2 seconds?

 

[Spark123]

As supplementary protection against direct contact using an old BS type RCD (300ms for BSEN), though as far as indirect contact is concerned I'd vote for 0.4s

 

[securespark]

Ok, I concede the shower. 5s it is.

As for the cooker, I would gice 0.4 if on a CCU & 5 if not.

Dedicated socket 0.2? Well, yes I suppose, but only by virtue of the fact it should be RCD protected.

Having said that, it may be protected by a BSEN 61008/ 61009 device, it which case it would be 0.3.....

 

[partpdoctor]

hi all
bearing in mind that with mcbs there is no 0.4 and 5s disconnection times- it will happen instantly with the correct amount of current..

i also note that the 17th edition is removing 5 sec disc all together, apart from "distribution circuits"
best wishes
alan

 

[securespark]

Missed that when I looked at the draft....interesting.

Have noticed however the figures in the EFLI tables are, in the most part, the same whichever table you look at.

 

[partpdoctor]

hi secure,
dont know how old you are but....
the 5 sec disc is from the 14th edition and earlier..
it was based on "fusing factor"
this was 3 for a rewireable fuse
2.4 for a hrc fuse and
1.5 for an oldie mcb

also note the draft has scrapped table 41C (alternative method) utilizing cpc resistance measurement

 

[Lectrician]

Isn't anything in a bathroom 0.4 - So upstairs lights, shower etc?

Everything else 5s, apart from any socket outlets - inc cooker panel if appropriate.

In any case, even if you put everything as 0.4 your fault current is 99% of the time going to the clear the fault within that time anyway.

 

[dingbat]

Isn't anything in a bathroom 0.4 - So upstairs lights, shower etc?

No. That requirement was removed when the 16th came into force.

As festa says, 0.4 secs for equipment outside with accessible exposed conductive parts.

 

[ColJack]

hi all
bearing in mind that with mcbs there is no 0.4 and 5s disconnection times- it will happen instantly with the correct amount of current..

there is no such thing as "instant".. it doesn't exist.. everything takes a finite amount of time..

having said that, yes MCB's should trip a lot faster than 0.4s..

 

[securespark]

hi secure,
dont know how old you are

I grew up on the 15th.....