Agricultural installations

[Sidewinder]

Remember if it is split phase as Andy says, "normal" switchgear will be operating above it's design voltage as split phase is normally 480V, not 400V.

This is what makes me think that it's TNS..... I've also priced for it being TT, just to cover the bases

View attachment 9807

I can't see is it 5 wire?

 

[Andy™]

Remember if it is split phase as Andy says, "normal" switchgear will be operating above it's design voltage as split phase is normally 480V, not 400V.

I can't see is it 5 wire?

come on Sidewinder, were harmonised now, its 460v

 

[NozSpark]

Here's a pic of the TX... I doubt that it's 3ph as there are only 3 HV conductors...



Maybe 4???

 

[phil d]

looks like a 3 phase to me, a couple of the farms I worked on had exactly the same setup, 11Kv to tx then the supply out, one had a3 phase and the other a single phase, had a very large earth rod planted at the base of the pole. I have been there several times when it was being worked on.

 

[Andy™]

Here's a pic of the TX... I doubt that it's 3ph as there are only 3 HV conductors...

Maybe 4???

the 11kv side is 3 phase

 

[Tony S]

If you look in knowledge base I’ve posted a list of UKPN’s standard transformers. 250/500V is the normal for split phase. You can get 2 pole MCB’s rated for 690V but keep an eye on the maximum fault clearance current, the higher the voltage the lower the clearance current.

For a 125A MCCB working on 660V single phase, I used a 4P breaker with two sets of contacts in series. I worked out the maximum fault current and it was scary, 132kA.

 

[Sidewinder]

Here's a pic of the TX... I doubt that it's 3ph as there are only 3 HV conductors...

View attachment 9810

Maybe 4???

You don't get a neutral on HV, so it's just 3 phases.

The DNO doesn't need to earth the metal frames on the top of posts so often they don't.

So I would agree that there is 3ph running across the top of the pole.

I can't see any more details, but, if there are 3 HV bushings into the Tx, then it's 3ph, & it'll be normal 230/400V.

 

[NozSpark]

Yeh, sorry guys.... must have had a brain fart there.... of course the HV is 3ph (no neutral),, what was I thinking?