A switch that "disconnects all poles"?

[davecla]

I need to get a single phase heatpump compressor wired in with a isolating switch.
The instructions call for a isolating switch the "disconnects all poles".

Is netural considered a pole?
If so, what is the purpose of isolating netural?

thx
dave

 

[ban-all-sheds]

Is netural considered a pole?

Yes.

If so, what is the purpose of isolating netural?

Increased safety.

 

[kevindgas]

not sure how much power the unit will draw as you haven't posted any info on the unit.
the fan isolation switches we use disconnect 2x live and 1 by neutral (or any combination of 3 wires) so may be of use to you
try screwfix 51728 -97 on page 263 it is 10 amp max though!

 

[ban-all-sheds]

I didn't think that Screwfix would deliver to New Zealand......

 

[davecla]

thanks for the replies, sourcing the switch isnt a problem (however the $180 price tag for a three pole 32 amp switch does make me gag!)

I guess my question is why isolate netural? I cant see how this increases safety unless the wires are incorrecly connected at the switchboard.

thx

 

[Paul_C]

a single phase heatpump compressor

three pole 32 amp switch

How many wires actually connect to the compressor, excluding the earth?

A basic single-phase motor (presumably 230V in New Zealand) will only need a double-pole isolator. Or does it have multiple connections for different speeds?

 

[ban-all-sheds]

A 7.3kW heat pump compressor?

That seems a lot...

 

[davecla]

Its on a 25A supply
Rated at 13.5Kw heating (ducted system)

Only a single phase to compressor, 2 Core + Earth cable

The reason I'm looking at a 3 pole switch as it seems the electrical suppliers stock these (for 3 phase jobs) but the 2 pole switches appear to be less common.

I'm still wondering how and why disconnecting netural aids safety but I'm resigned to shelling out the cash for one.
thx

 

[ban-all-sheds]

Can't you get brands like MK or Crabtree in NZ?

32A DP switches are made by all the major accessory manufacturers, and you can buy them in DIY stores over here.

What do people in NZ do for cooker switches, shower switches etc?

BTW - doesn't 7.3kW in 13.5kW out mean you have a COP of less than 2?

 

[davecla]

Never seen MK or Craptree, most of our switch gear seems to come from australia.

I should have added this was for outdoor use so needed to be waterproof rated (IP66 in our case)

We are not permitted to touch any fixed wiring - can't replace a light switch or powersocket for example so DIY stores only stock the most basic fittings. NZ has become a nanny state hell bent on crushing DIY.

Anyways I've gone out an purchased a three pole switch (cause i was easier to find than a two pole one) so I'm away now.

Thanks

Dave

 

[mattylad]

The ideal switch to disconnect all poles would be the one that turns off the channel tunnel trains & stops the ferries