Stroma Certification Scheme stroma assessment this week

[phil lancaster]

Hi in the shed I screwed the swa gland into a plastic through box and connected the plastic through box to the bottom of the metal consumer unit in the shed that was so as not to incorporate the house earth
phil

 

[Gavin John Hyde]

mmm ok
in the house consumer unit I have fitted a 20RCBO to the swa cable the swa cable runs to the shed into a metal garage consumer unit in the consumer unit there is a 40RCD main switch then a 6 amp mcb and a 16a RCD then I try to test the RCD main switch for the tripping time for the inst cert the house rcbo trip
I hope someone can help out as I have my CP assessment at 10 tomorrow
thanks

Am i seeing something i shouldn't here
House = 20 amp RCBO
Shed 4oamp RCD main Switch
Shed 16 Amp RCD (assume for socket radial?)
Again assuming all are 30mA

so RCBO ----->RCD ---->RCD

Sounds like rock, paper and scissors which one goes first along the line?

To the OP i would go look up discrimination between RCD's connected in series. if they are both rated same (30mA?) then the issue is which one trips first when you test them or in fault conditions. especially if one is very sensitive,

 

[westward10]

You might want to put a warning notice on the enclosure, "contains different earth bla bla bla ", they like all that.

 

[westward10]

Am i seeing something i shouldn't here
House = 20 amp RCBO
Shed 4oamp RCD main Switch
Shed 16 Amp RCD (assume for socket radial?)
Again assuming all are 30mA

so RCBO ----->RCD ---->RCD

Sounds like rock, paper and scissors which one goes first along the line?

Don't think the 16A is an rcd, but yes.

 

[Ian1981]

Hi in the shed I screwed the swa gland into a plastic through box and connected the plastic through box to the bottom of the metal consumer unit in the shed that was so as not to incorporate the house earth
phil

Do away with rcbo change for mcb and your garage lights and sockets will be in its own rcd

 

[westward10]

Do away with rcbo change for mcb and your garage lights and sockets will be in its own rcd

And hope they don't pick up on division of circuits at the garage board

 

[Ian1981]

And hope they don't pick up on division of circuits at the garage board

Depends if the assessor is a grumpy git

 

[phil lancaster]

hi I have connected the armour into the house earth to cove the swa cable to the shed then in in the shed I connected the gland of the swa cable into the bottom of a plastic through box then connected the plastic through box to separate the earthing types
phil

 

[Gavin John Hyde]

And hope they don't pick up on division of circuits at the garage board

Hahaha... A mate and fellow electrician had his annual AC assessment from NICEIC last month and his assessor told / mentioned to him that quote' it is the new expectation on new installations now, that to avoid unsafe situations in the event of a circuit failing that lighting should be divided between sides of the property rather than floors, so the owner still has lights on each floor in a fault situation'
so you can have front and back, or left and right but no more upstairs lights downstairs lights on their own circuit.... it might cause poor mrs smith to fall over in the dark i guess. personally i think its a bloody silly idea and i would have told the assessor, no problem, ill put every bloody bulb on its own mcb to keep you happy. if it isn't broke why fix it...

 

[Gavin John Hyde]

hi I have connected the armour into the house earth to cove the swa cable to the shed then in in the shed I connected the gland of the swa cable into the bottom of a plastic through box then connected the plastic through box to separate the earthing types
phil

But have you listened to what people have been saying about the rcbo in the house CU? remove that and swap for a MCB. First thing tomorrow or even tonight if you have a store open by you is go get a correct size MCB.

 

[Ian1981]

Hahaha... A mate and fellow electrician had his annual AC assessment from NICEIC last month and his assessor told / mentioned to him that quote' it is the new expectation on new installations now, that to avoid unsafe situations in the event of a circuit failing that lighting should be divided between sides of the property rather than floors, so the owner still has lights on each floor in a fault situation'
so you can have front and back, or left and right but no more upstairs lights downstairs lights on their own circuit.... it might cause poor mrs smith to fall over in the dark i guess. personally i think its a bloody silly idea and i would have told the assessor, no problem, ill put every bloody bulb on its own mcb to keep you happy. if it isn't broke why fix it...

Hope the niceic assessor showed your mate were it states you have to do this?
I appreciate splitting lighting circuits on 2 sides of an rcd but left to right of a house is asking for trouble and is ridiculous in my opinion.
I'd have told him to get stuffed!

Our company had its assessment other month and nothing like that was said, so it just shows how on the ball and consistent these guys are

 

[phil lancaster]

hi the reason for the rcbo was that a mate in the trade advised me to do so thought it was a bit strange I have some cb in the van I will replace it now advise in the size would a norm 20A cb be ok in the house going to the main switch in the shed that is 40A rcd TT system
Phil

 

[westward10]

I assume your mate isn't an electrician.

 

[phil lancaster]

Well I hate to tell you yes he is I will be telling him what I think tomorrow afternoon the sod what size mcb do you think I should replace the rcdo with the cable is 4mm 2 core swa
phil

 

[Andy78]

Well I hate to tell you yes he is I will be telling him what I think tomorrow afternoon the sod what size mcb do you think I should replace the rcdo with the cable is 4mm 2 core swa
phil

You have designed and installed it so you should know how to size the MCB through calculation.