Help to solve mystery electrical outages,

[kerching]

BUT the supply to the B Bar remains?

So fault is after B Bar?

I am not going to use the correct terms as it takes too fricking long. But, I would firstly disconnect each end of the subs and meg them end to end at 1000v to see if something is breaking down, as just doing an Ins Test wont really tell you much in this case.

Pesonally I still thing it is a faecal connection.................... :coat

Just thought, when this happens do you still have a neutral at the B Bar chamber?? or do you just think you have as you are recording voltage between phase/line current

 

[springcrocus]

I might be thinking along the same lines as Kerching, but you've stated a PME supply. How confident are you of your readings?

I would have thought it sensible to bang a rod in somewhere nearby as a local earth and take a bunch of readings using this as your earth reference, rather than the DNO's neutral.

Or I might be talking hogwash, of course.

 

[steptoe]

well, Ive stopped questioning peoples PME statements,

if they had the intelligence to actually know the difference between PME and TNCS then they might be able to find faults faster,

and if they dont then they should post in the learners section.

 

[park1]

The switch gear is all brand new Snieder.All connections have been tested,checked, pulled pushed.

We have ruled out loose connections and dodgy switch gear on the basis that the outages are affecting 2 separate sub mains albeit connected to the same bus bar.

A loose connection would generally have other signs such as elevated current at times of higher impedance, or signs of over heating.

The load has been diliberatly unbalanced to create stress on the neutral to try and recreate the fault ( as we assumed a neutral issue due to the commonality of the issues) this changed nothing.

The outages appear to move from one board to the other???

We have ruled out sabotage as the pub chain moved out all the staff for two weeks and brought in new, and the issues still appear?

The voltage and current are lost across all phases and neutral at time of each outage.

What testing has actually been carried out, what has been verified and how?

 

[Evans Electric]

OK Based on what we have heard so far, the BB is fine so someone wants to go out there and get a grip :-

You're now left with :-

Loose connections on both the Sw/fuses on the BB ,or loose fuses, or badly fitting blades or loose outgoing connections.

Connections at both dist. Bds, on the main switch .

Short of actually going there what can be said that hasn't been said.

 

[steptoe]

mmmm

for my tuppence,

is there something somewhere with a massive inrush at start-up that is pulling the voltage waaaaaaay down for a fraction?

 

[Steve3948]

mmmmfor my tuppence,

is there something somewhere with a massive inrush at start-up that is pulling the voltage waaaaaaay down for a fraction?

is tuppence the same two pennith ??