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Duane B

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Hi been to look at a little unit today, no big deal new board needed 6 way,   2 car ramps single phase, couple tyre machines, sockets and lights etc, board fed from a 3 phase board next unit via a 6mm twin and skin naughty but customer don't want new swa, plus it's been In for years, no front either on existing board. 

Issue

Main 100A switch not there, so someone has back fed an mcb to energise the bar not good, as I'm not familiar with square D. Plus no rcd at all in the unit at all, excuse my lack of knowledge here I mainly only do domestic stuff. 

Type QO-E  type 2  duty M9 

Are these mcb equivalent to our new C type curve mcbs single pole. 

Dont wanna fit a board and have inrush tripping all over the show, plus is it wise for rcd main switch on the C/U

Cheers guys, 

 
erm... providing its clearly marked as main switch, and there isnt any gaping holes where the main switch would have been, whats the problem?

and if its commercial, then you dont always need RCD's anyway

a little knowledge is dangerous....

 
Last edited by a moderator:
Page 75 of the OSG will show the trip currents and applications for the various circuit breaker types as in B,C,D and 1,2,3 & 4.

 
We need to know the amp setting really, type 2 breakers are BS 3871. Type 2 is not as you say equivalent to C curve.

They are similar but not the same for the newer BS 60898 breakers, and the maximum Zs for them is subtly different.

I have just done a test on an industrial unit that had previous records showing that the system has been inspected and maintained properly, however they failed to notice that what they thought was a RCD was in fact a RCCB. Its all down to knowing the BS standard and applying those in your report.

The install you describe is I would guess a garage?

If so there are other regulations far beyond BS7671 that would apply to the installation. Now I could if I wish go into a diatribe of relevant regulations, however I would expect those who do this type of work would know them, so I fortunately am saved and need not.

The customer as you say, needs to comply with the regulations, if he does not, then he is in breach of every employment regulations and health and safety regulations. As the electrician giving advise you have to be firm, be confident, and walk away when they do not accept your advise.

 
We need to know the amp setting really, type 2 breakers are BS 3871. Type 2 is not as you say equivalent to C curve.

They are similar but not the same for the newer BS 60898 breakers, and the maximum Zs for them is subtly different.

I have just done a test on an industrial unit that had previous records showing that the system has been inspected and maintained properly, however they failed to notice that what they thought was a RCD was in fact a RCCB. Its all down to knowing the BS standard and applying those in your report.

The install you describe is I would guess a garage?

If so there are other regulations far beyond BS7671 that would apply to the installation. Now I could if I wish go into a diatribe of relevant regulations, however I would expect those who do this type of work would know them, so I fortunately am saved and need not.

The customer as you say, needs to comply with the regulations, if he does not, then he is in breach of every employment regulations and health and safety regulations. As the electrician giving advise you have to be firm, be confident, and walk away when they do not accept your advise.
Hi cheers for input guys, it is indeed a small garage back street jobby one man band type setup. Holes in the board lol, comply with ip ratings lol, there is no front cover on the board and a 6mm twin and earth goes in through where the cover should be fitted, onto a 32 amp mcb to energise the bar as the main switch had burnt, so some one had removed it and got it to work via the spare 32 amp mcb reverse fed,  I didn't go for an eicr he don't want b to pay, just wants the board made better safer. 

 
Given the information that you've supplied then I'd say that it needs replacing.... end of

If he doesn't want to spend a bit then walk away...... after giving him a danger notice if it's deserved

 
Garages are notorious for not liking to spend money ....just charge it.......   from back street  bodgit & codgits to respectable repair shops , they hate spending on the workshop .

 
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