You need scrambled brains to sort this!

[Knobhead]

This was posted on one of the other forums I go on. Just see if you can work out this fault (it's been on a bit of a body building course).

Dear Sirs,

In our plant we have 2no.s substations no.1 substation has a main switchboard with 2no.s11/.44KV 1600KVA tx They connected to switchboard by 2no.s acbs and a bustie. No.2 substation has no tx it is supplyed by 2no.s acbs from substation 1 it has bestie. I have removed bustie nutral at substation 1 all single ph thing are fed from substation 2 bustie open with nutral. The earth abcs at no1 swichboard keep trips they feed switchboard2
Can you help pleasse

There have been a couple of threads in the last few weeks with exactly the same fault. I’ll post a drawing later but that would give the game away to quickly. You have to try and picture it from the description.

E54 and Malcolm are not allowed to answer.

 

[Engineer54]

Your just a spoil sport!!! :angel_smile:

 

[malcolmsanford]

Col .....................l'm sitting on my hands here .....................

 

[ian.settle1]

Get someone who knows what their talking about to do the posting correctly

bustie? does it have big -----

bestie? bestie what

Think his brain is scrambled

 

[Richard Burns]

In our plant we have 2no.s substations no.1 substation has a main switchboard with 2no.s11/.44KV 1600KVA tx They connected to switchboard by 2no.s acbs and a bustie. No.2 substation has no tx it is supplyed by 2no.s acbs from substation 1 it has bestie. I have removed bustie nutral at substation 1 all single ph thing are fed from substation 2 bustie open with nutral. The earth abcs at no1 swichboard keep trips they feed switchboard2

That is a description!!! I would try to answer but know I would just look foolish.
However for Ian from the urban dictionary: bustie - a girl who puts out
It is starting to look like a better description but I can't imagine why he removed them or what they are like when open with nutral!

 

[Chr!s]

Bustie should be Bus tie as in two Bus tied via a Breaker.

 

[Knobhead]

First point to the man from Staffordshire

View attachment 14741

 

[Guest123]

Quote "I have removed bustie nutral at substation 1"

Does that mean there isn't a neutral being supplied to sub-station 2 where all the "single ph thing are fed from"

Meaning that the earthing is being used as a return path for all the SP loads causing the ACB's to trip???

 

[ian.settle1]

Bustie should be Bus tie as in two Bus tied via a Breaker.

Known it to be called a bus coupler as well

 

[Knobhead]

Quote "I have removed bustie nutral at substation 1"

Does that mean there isn't a neutral being supplied to sub-station 2 where all the "single ph thing are fed from"

Meaning that the earthing is being used as a return path for all the SP loads causing the ACB's to trip???

Nope!

You think this board is a headache, we have these all the time! Half the fun is trying to fathom out just what the OP is on about.

PS your warm, but no coconut. You'll kick you're self when I show the drawing.

 

[Knobhead]

Known it to be called a bus coupler as well

Bus tie, bus-coupler, bus section,,,,,,, All the same flavour. The Indians favour bus-tie, the Americans bus-coupler.

 

[Chr!s]

No neutral, no star point, unbalanced loading Affecting voltages.

 

[Knobhead]

OK first clue:

Think of neutrals and CU's

 

[plugsandsparks]

Wild guess, their CT wiring is wrong way round

 

[Guest123]

Substation 2 is getting it's 3 phases from ACB1 whilst the neutral is returning on ACB2 due to the bus-coupler being open giving unbalanced loads as they're 1P???

 

[johnboy6083]

is this a TNC system?

 

[ian.settle1]

No neutral 400v across single phase equipment

 

[johnboy6083]

thats kinda the route im thinking, the lost neutral situation, neutral currents returning via the metalwork. Does this system incorporate phase failure relays that would shunt trip the ACB on voltage imbalance?
where are the neutral-earth bonds for the star point of the tx? if any

 

[Knobhead]

I should have banned you Lenny. In effect it's our old friend a shared neutral.

Here's the drawing I had to do to work it out.

View attachment 14750

 

[Knobhead]

The guy still wouldn’t accept it.
It’s not very often you get a Indian university professor loosing his rag, but he convinced the guy I was right.