Isolator for AHU

[Rather be Fishing]

Hello guys I've been having quite a nice run where I haven't come up against anything that I wasn't already familiar with until today that is.


Hopefully someone is about as I've kind of already ploughed in.

Obviously I've made sure it is safely isolated.

I though I better just have a quick look inside the new isolator to make sure they look the same and low and behold they don't and I was wondering to save me the embarsment of blowing anything up could you clarify what goes in this terminal marked N1 as it's putting me off a bit.

The first pic is of the old isolator

And the second is of the new isolator

My question was if anyone wouldn't mind helping me out here is what is that N1 top and bottom terminals on the new isolator.

Logically I'm inclined to take the two little white cables you can see in the first isolator and put one each into the terminal marked N1 on the new isolator


Or should I be taking the neutrals in the connector block of the first isolator pic into the n1 terminals on the new isolator.

Sorry if that is a silly question

But I'm unsure and some advice would be helpfull

Fingers crossed

 

[Rather be Fishing]

I think I'm gonna wait on this and just put the cover back on for now and leave it as is.

Once I know the answer I can come back and fit it

 

[Rockingit]

The N(1) is the joining of the neutrals, same as the old connector block. It's just unhelpfully labelled.

What's curious though is the use of white cable for what would normally be the G/Y cpc - it looks to be (and should be if it's white) a functional earth, not a cpc, yet there doesn't appear to be a cpc present either which there almost certainly should be.

 

[Rockingit]

My bad - closer scrutiny and it looks like the CPC lurking in the back has just been banjoed directly to the tag

 

[snowhead]

The new isolator is not compatible.
The block where the white cables are is an auxilliary contact and will form part of the control circuit.
It most likely in circuit with the main (overload?) contactor for the unit or may be also be part of a reset required circuit.
Could be conected to BMS to show the unit is OFF
The new isolator needs to have the Aux, do not link the whites permanently.

 

[Rather be Fishing]

It looks like I was right to be cautious. Sometimes I need to slow down and have a look at the new unit before I plough in.

It's good to know that the N1 terminals were for the neutrals and would have meant taking them out of the connector block and 're homing one in each N1 terminal which shows my hunch was right

Another chap from the firm turned up and just fitted it putting the whites from the first isolator into the terminals labelled N1

I think I better give him a ring and relay what I've been made aware of

 

[Rather be Fishing]

Well I just called him to let him no what I had been told by my sparky mate who I go to whenever I have something I'm unsure about ?

And said that it turns out that that isolator is not compatable and it requires a auxilliary contact

And he said well he put that one in with one white going to one N1 terminal and the other white the other N1 terminal, so in effect I'm guessing permanently connected and what I've been told not to do.


I'm guessing that my doing that it is eventually gonna ---- the AHU

He said he will get one with a auxiliary contact and replace it when he can

Not sure if that is safe however and if I need to tell that it isn't.

What will eventually happen if those whites are linked @snowhead

Thank you