32a three phase isolator neutral bar?

[BiddeldyBwah]

Came across one of these today at work. Had L1 L2 L3 and switched Neutral, but also had an N link bar inside.

Just wondering what it's for?

 

[westward10]

Your description is a bit non specific. Can you show a pic or state a specific isolator.

 

[ElectroChem]

Could be used if you didn't want to switch the neutral in that application, cuts down on number of SKUs to stock.

 

[ipf]

I'd like a view of it before commenting, too.
Although, it seems like a switch that can accommodate different supplies...as most 3 phase switches do.
ie, some machines don't require a neutral......but then again WTF is it feeding?

 

[Marvo]

We also often see a 4 pole isolator that has a neutral and earth bar internally as well. It's just to acommodate different wiring options with switched or unswitched neutrals as far as I know.

 

[ElectroChem]

We also often see a 4 pole isolator that has a neutral and earth bar internally as well. It's just to acommodate different wiring options with switched or unswitched neutrals as far as I know.

Reminds me of one job where we used a 4 pole isolator for a large motor. 3 poles for the motor and the 4th for the cooling fan, with the fan neutral unswitched.

 

[BiddeldyBwah]

Hey i took a picture.

The supply eventually came into L1 L2 and L3, and the N on the right hand side of the device. But there's still the metal N bar on the right. Just wondering at what configuration you would put the neutral in there instead of into the switch.

They are feeding welding machines.

 

[ElectroChem]

As above, looks like a standard enclosure that the manufacturer could use for everything from single to six-pole isolators. Yours clearly started life as a 3-pole, with the 4th tacked on. I can think of at least 3 scenarios where your neutral would not go through that pole, from isolator feedback to forced air cooling to switching the armature and field of a DC motor. I think you might be getting a bit hung up on this 'extra unneeded neutral bar'. It likely adds about 10p to the cost of the isolator, so use it or don't as appropriate.

 

[BiddeldyBwah]

As above, looks like a standard enclosure that the manufacturer could use for everything from single to six-pole isolators. Yours clearly started life as a 3-pole, with the 4th tacked on. I can think of at least 3 scenarios where your neutral would not go through that pole, from isolator feedback to forced air cooling to switching the armature and field of a DC motor. I think you might be getting a bit hung up on this 'extra unneeded neutral bar'. It likely adds about 10p to the cost of the isolator, so use it or don't as appropriate.

I'm a trainee so was just wondering why it was there.

 

[ElectroChem]

I'm a trainee so was just wondering why it was there.

Ah, that explains quite a bit, and means I must also apologise if I went a bit hard at you. I was treating your question like a tradesman was asking "What's a screwdriver for?" rather than a learner looking to learn.

 

[BiddeldyBwah]

Ah, that explains quite a bit, and means I must also apologise if I went a bit hard at you. I was treating your question like a tradesman was asking "What's a screwdriver for?" rather than a learner looking to learn.

No probs mate. This is year i get to ask stupid questions ?

 

[snowhead]

As it's for a trainee I'll just add that if it's a Neutral contact will be early make / late break compared to the L1, L2, L3 contacts.
But I'll leave them to find out the importance of that.

 

[westward10]

Hard to see from the picture but is the fourth switch terminal marked as N.

 

[snowhead]

Even magnified it doesn't appear to have a marking on the 4th contact, jut the arrow in the plastic case.
From the style (plastic screws) it looks to be a Europa, which also appears very similar to older Klockner style disconnectors.
There's space on the left side for another contact so it may be that the 4th contact is auxiliary and could have a 5th.
The 4th contact will have details on the side.

 

[BiddeldyBwah]

Hard to see from the picture but is the fourth switch terminal marked as N.

No it's just bare. The guys i am working with said it was the N though. Incidentally we were hooking up machines with no neutral anyway.

It's an 'Eris Industrial' 32a/20a from Yesss.