Power problem in new house

17larsson

Bulbs are constantly blowing, the TV flicks on and off sometimes and the main 63A mcb trips every few days. The ESB have come out and measured the voltage at the meter over one week and say it's fine.
The Voltage seems to be a constant 235v at the meter and the same at any outlet inside the house.

A loop reading at the meter gives me 1.8ohms. This is higher than normal but it's hardly the reason for the problems is it?

tomdempsey200

tn-c-s should be about 0.35 ohm maximum at the supply if i recall...you're Zl readings must be way over at 'final circuits' if that's the case

it sounds like maybe there a supply problem with a bad connection or volt drop on the supply lines on the network etc. going by what you're saying...what's the volt drop like with a heavy load

is everything ok at the distribution board and all connections tight

Zen65

17larsson wrote: »

A loop reading at the meter gives me 1.8ohms. This is higher than normal but it's hardly the reason for the problems is it?

How are you measuring the loop impedance?

tomdempsey200

Zen65 wrote: »

How are you measuring the loop impedance?

something not right

is this the 'main ocpd'(63amp mcb) in the cabinet that's tripping i wonder


i'd be checking connections at mcb and distribution board anyhow

or is there overload condition or disturbing loads present tripping 63amp mcb if ESBN have recorded voltage and found no issues

17larsson

tomdempsey200 wrote: »

tn-c-s should be about 0.35 ohm maximum at the supply if i recall...you're Zl readings must be way over at 'final circuits' if that's the case

it sounds like maybe there a supply problem with a bad connection or volt drop on the supply lines on the network etc. going by what you're saying...what's the volt drop like with a heavy load

is everything ok at the distribution board and all connections tight

Yeah the readings inside are high as 2.8ohms. I've seen a few houses with a supply impedance of 0.5 or 0.6 but never as high 1.8 so that's why I just thought there might be a link between that and the problems they are having. I might stick an ammeter on and see if there any funny readings. All connections are tight

tomdempsey200

yes

if it's actually 1.8 at the supply you will need to contact esbn

but that should have showed up as an issue on a voltage recorder unless it's a problem with the short neutralizing
section at the cabinet

17larsson

I would have thought the ESB would have noticed the high impedance when they were testing the voltage but maybe not. I must ask the spark that originally wired the house if he got those readings when he tested the house initially. Yeah it could be a loose neutralizing connection under the seal. I will talk to the original spark tomorrow and see if I can get any more info