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niloc1

New to the trade and lots to learn! So I've filled in my very first installation certificate - but what is the Type BS(EN) of the main switch on this BS3036 semi-enclosed fuses consumer unit? It's 250V, 80A but no more markings - is it relevant for this old board? Also why does my tester not display the PFC in kA as asked for on the form - I get 0.17 ohms. Help!

niloc1
 
The bs no. is probaly 5419 which has now been superceeded by bs en 60947-3 on newer cu's as for the pfc this is the prospective fault current i think they require it from phase to earth so ohms law 230/0.17 gives you the current,
Hope this helps
AJ
 
If your meter dosn't have a pfc test option just divide your 0.17 into the line voltage to get you pfc in amps then divide this into 1000 for Ka
 
The bs no. is probaly 5419 which has now been superceeded by bs en 60947-3 on newer cu's as for the pfc this is the prospective fault current i think they require it from phase to earth so ohms law 230/0.17 gives you the current,
Hope this helps
AJ

Many thanks - that's great! :)
niloc1

If your meter dosn't have a pfc test option just divide your 0.17 into the line voltage to get you pfc in amps then divide this into 1000 for Ka

Thanks darkwood - niloc1
 
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Just couldn't remember off me head but you sound correct lenny thank you for the clarification
Regards
AJ
 
just an addition to your query if your looking for pfc on a three phase system you need to find it from the highest result from the 3 line supplies then double it before you write it down.
 
just an addition to your query if your looking for pfc on a three phase system you need to find it from the highest result from the 3 line supplies then double it before you write it down.

On this point I know you have to double the highest reading on 3 Phase but can't remember why? Can someone enlighten me please???
 
On this point I know you have to double the highest reading on 3 Phase but can't remember why? Can someone enlighten me please???
In single phase a short circuit L-N or L-E is 230v where as in three phase you have to consider a short between the phases 400v which will nearly double the fault current and as most meters cant test between phases its easier although crude to just double it.
 
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