Tests for replacement consmer unit

[Jon_]

Could you tell me whether most of the tests carried out for a Domestic Electrical Installation Report would have to be repeated if a replacement consumer unit is subsequently fitted?

 

[Deleted account]

Could you tell me whether most of the tests carried out for a Domestic Electrical Installation Report would have to be repeated if a replacement consumer unit is subsequently fitted?

If it was you who carried out the EICR a few days previous I would use the same reads, however I would redo Zs and obviously any any new residual current device tests.

 

[westward10]

Yes. Continuity of cpcs/ring final conductors/ main protective bonds, insulation resistance, polarity, Ze/Zs, rcd/rcbo tests.

 

[Pete999]

Could you tell me whether most of the tests carried out for a Domestic Electrical Installation Report would have to be repeated if a replacement consumer unit is subsequently fitted?

Look at Best practice guide no 1 for a CU change
Earthing and bonding continuity
Global IR test need L/N to Earth is acceptable
RFC continuity
Polarity

 

[stummish]

I'd retest ze, ring continuity, zs for each circuit and obviously any new rcds. If you feel you have to retest insulation then something has gone very wrong with the new install.

That being said, if someone else had done the eicr I'd do a full retest. Some EICR's are tested using eyeballs and imagination, not test meters!

 

[Specialist]

Oh heck, are we supposed to use test meters ?

 

[1Justin]

Full test IMO is the only way. On old houses needing a CU, it's normal to find lots of faults. Open rings, reversed sockets, no CPC, borrowed neutrals, nails in cables, no bonding, inadequate earth, mice...Just so many problems... I have spent a week doing CU on 2 bed houses before.
It pays to spend long enough beforehand to tell customer up-front what to expect, then build that into quote with a further contingency for unknown faults . I tend to try to do 80% of the tests with the old CU in place, ideally the day before. Also get all major faults fixed then, because once new CU is in, you'd have otherwise A) connected in faulty circuits, or B) maybe lost the will of the Customer to pay more, since they see the shiny unit and assume it's done. -Puts you in a spot.
Doing it up-front means that where it's really bad, I can tell them without first having destroyed the old set-up. Basically an EICR every time, but without the paperwork (since that's all built in to the subsequent EIC ). Working alone, where circuits need extending (really common), new tails/EC/bonding etc (really common) , and faults fixed (nearly always necessary, sometimes taking ages..), there's just not enough hours in a day to do it all and switch it on the same evening knowing it's safe. - It's just not worth the risk of getting caught short at 9PM after a tough twelve hour day.
I nearly never do a CU in 1 day, and only connect one in when I am 80% sure of all the tests results already, making finishing the testing and sealing possible the same day.

 

[Rpa07]

Good post @1Justin - I spent 4 hours testing an old installation and noting my readings then labelling in order to have an easier time of changing the CU this week. Left it working with a couple of circuits, that didn't need to be on there to function, disconnected until new CU.
I don't think that many things are as quick as you think they will be, double the time you think and you'll be closer.

 

[stummish]

I assumed testing before, I think the op meant: testing first, cu swap, after cu swap was a full test necessary. But always test first.

 

[Pete999]

Downloads

I assumed testing before, I think the op meant: testing first, cu swap, after cu swap was a full test necessary. But always test first.

The OP is asking WHAT test he should do before swapping the CU

 

[stummish]

Domestic Electrical Installation Report would have to be repeated if a replacement consumer unit is subsequently fitted?

I took that to mean testing had already been done previously.

 

[Specialist]

To be honest, so did I. To me it seemed like EICR had been done, CU needs changing out & he wanted to know if he had to do it all again afterwards.

 

[Pete999]

Alright Alright I give in

 

[stummish]

Sorry @Pete999 you have to be wrong at least once in your life. Maybe one day, I hope I can be as right as often as you!

 

[Specialist]

Sorry Pete