E7 Ze & PFC measurement??

[Jay Sparks]

Hi Guys & Gals,

So Im fitting two small 1.7kw storage heaters on Monday. There is already two fitting, fed from an old Wylex cu with rewireable fuses. The cable for the excisting heaters are buried. So my first thought was to fit a new 4 way rcd board so I could add the two new ones. Now I know you can have problems with nuisence tripping of the rcd when the E7 kicks in so, heres what Im going to do!

The customer doesnt want me to chase the walls, he is fine with the cable being run in pvc mini trunking. (not my idea.lol). So I can leave the excisting heaters and board as is. I intend to fit another small 2 way cu next to the excisting E7 cu.

What I want to know is, as both the E7 & 24hr boards are fed from the same service head and meter and they are virtually next to each other, can I use the Ze & PFC reading from the 24hr cu and just make a note on the cert? Or, would you just make a note on the cert why you couldnt carry out the live tests?

Any thoughts or info would be great. If Ive missed something obviouse, I accept your critisism.lol

Jay

 

[DNS1]

I'd use the same PFC and PSC as measured from the general use board...

 

[NickD]

Is there not then a risk of missing a problem with the tails or earthing conductor (or connections to them) on the Ec7 board? Just asking, like. I notice DNS1 doesn't specifically say use the Zs from the main board. Agreed that PFC is unlikely to be any higher. There is definitely a responsibility to confirm the earthing arrangements and not just take it as being OK.

 

[Jay Sparks]

Is there not then a risk of missing a problem with the tails or earthing conductor (or connections to them) on the Ec7 board? Just asking, like. I notice DNS1 doesn't specifically say use the Zs from the main board. Agreed that PFC is unlikely to be any higher. There is definitely a responsibility to confirm the earthing arrangements and not just take it as being OK.

The Zs can be taken by temporarly connecting the E7 cu to the 24hr cu. But I would still need a Ze reading and I think the best way would be at the 24hr cu. I suppose I could always go back at 12am and do the live testing then.lol

 

[MDJ]

Cut the seals and spin the meter until the off peak livens up hahaha, JK, don't do it kids' it's illegal.