OP
itsonly3wires
@westward10 Zs measures outside minimum Zs values at a sub-board supplied from this DB.
Discuss New here... and here is a an interesting DB I've come across... need some help with EICR for it! in the The Welcome Forum area at ElectriciansForums.net
I here what you are saying and you maybe right.@Ian1981 swimming pool pumps, sauna, spa air pump are high demand (for a residential install) and they are normally in use simultaneously. Then add in an electric hob, and oven and we are starting to pull close to 80amps.
I'm lazy with my demand calculations... but I suspect that the demand is higher than 125Amps. I can see 40 Amps in the swimming pool plant room. There are 2 kitchens and 3 american fridges. Air conditioning and a 16Amp inverter for motor drive in a workshop.
Fair enough you are the inspector.@Ian1981 I have...
If I sum L1,L2 and L3 (which is actually all L1 because it is not 3 phase) then I arrive at around 28 Amps and that is a "quiescent" current... there was no one home. That is all just fridges and pool filtration.
I obviously can then see that 28Amps (all of it) on the neutral. Because the current is all flowing through that conductor.
So I can see the building demand being in excess of 125A and that is fine when you consider the line conductors and the 125A x 3 switching of the line conductors.... but there is a 125A switch in the neutral and it all goes through that one pole.
I would honestly do a load check with a clamp meter.@Ian1981 No evidence of thermal damage. Main switch makes and breaks. No heat anywhere in and around the DB.
It has been installed like this for 20+ years.... but I don't want to be the one to EICR it as OK and then the smoke comes....
Why not put a clamp meter on the tails (each one at different times) and see what load it's pulling?
At a glance things look normal ! Thanks ...Thanks for a most interesting thread.
Reply to New here... and here is a an interesting DB I've come across... need some help with EICR for it! in the The Welcome Forum area at ElectriciansForums.net
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