Max disconnection times for 50a shower circuit ?

[Toby Kuhnert]

Hi guys,

Just doing an EIC for a recent dis board change, I also installed a 50a (type b 60898) shower circuit for an 11.5KW shower. I am looking through my regs trying to find whether it comes under the 5s disconnection time...? I know 0.4s is for circuits less than 32A and non-distribution circuits, so from that I would conclude that the shower is 5s, but I have heard because it is in a special location, it comes under 0.4s. Is this true? Have looked through 411.3.2.2 and also the special locations section but nothing immediately jumps out at me regarding this.

Any help would as ever be much appreciated

Toby

 

[Ducksy]

60898 disconnection time from 0.1 to 5 sec are the same for a fault current 5x it's current rating on the chart so it Don't matter.

 

[Toby Kuhnert]

60898 disconnection time from 0.1 to 5 sec are the same for a fault current 5x it's current rating on the chart so it Don't matter.

Ah OK that makes sense, thanks for clearing that up

 

[Ducksy]

No probs. If it was a lets say bs3036 I think it's 5 seconds but I'm sure others can verify.

 

[Geoffsd]

Won't it be 0.3s because of the RCD?

 

[telectrix]

the RCD should dis. within 300mS. but it's the max. time allowed, he's asking for.

 

[Des 56]

Whats the maximum disconnection time for when "the wife" is taking a shower

5 secs a tad harsh do you think

 

[Geoffsd]

But as it must have an RCD, doesn't that count?

Would it still be 5s with 3036 and separate RCD?

 

[telectrix]

RCD in irrelevant. the disconnection time required relates to a fault of negligible impedance L-N or L-E. the disconnection time should be met by the combination of PFC and the OCPD. the RCD only comes into the equation on a TT system where dis. times can't be met otherwise. the RCD is there for additional protection on a TN system.

 

[SirKit Breaker]

5 second disconnection times are for distribution circuits protected by fuses of whatever number. BS60898 mcb's have the same max Zs values for 0.4 and 5s disconnection, times its all in the appropriate tables in both BGB and OSG.

Cheers..............Howard

 

[somersetsparks]

I would put 5s in the box ona test sheet, however as said above it doesn't matter with 60898's