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.