shower priority unit positioning

[davesparks]

He could take the 5 core to one CU and feed the shower from there.

It would be bad practice to have a circuit in the CU which is not isolated by the mainswitch of the CU.

 

[mainline]

It would be bad practice to have a circuit in the CU which is not isolated by the mainswitch of the CU.

Use a contactor or a 3 pole main switch

 

[nicebutdim]

do you think 10mm would work?

I've no idea what would work, for reasons previously outlined and others had already made the same point.

If you correctly guess how long the piece of string sitting in my cupboard is, I'll take a wild guess at answering your question.

 

[davesparks]

Use a contactor or a 3 pole main switch

I don't see how that will help.

 

[mainline]

I don't see how that will help.

Using a 3 pole mains switch would isolate all circuits.

Using a contactor would isolate the outgoing shower circuit.

Using a CT relay at the House would mean you could also limit other circuits if there was lack of capacity.

 

[James]

Using a 3 pole mains switch would isolate all circuits.

Using a contactor would isolate the outgoing shower circuit.

Using a CT relay at the House would mean you could also limit other circuits if there was lack of capacity.

a contactor will normally turn off a circuit but i would not consider it isolated.
not trying to be pedantic but we should use the correct terms for things as professionals so that we leave nothing to the imagination or interpretation of our words.
unless of course you think a contactor is a suitable means of isolation and then i would just call you out as Wrong.

 

[mainline]

a contactor will normally turn off a circuit but i would not consider it isolated.

Why not ?

not trying to be pedantic but we should use the correct terms for things as professionals so that we leave nothing to the imagination or interpretation of our words.

What term did I use that was wrong ?

unless of course you think a contactor is a suitable means of isolation and then i would just call you out as Wrong.

Table 537.4 60947 contactor isolation = yes

 

[mainline]

James said:
unless of course you think a contactor is a suitable means of isolation and then i would just call you out as Wrong.



No more debate ?

 

[Midwest]

Ok.

I'm thinking a contactor has a control circuit, which would operate said contactor. Whereby you could isolate the control circuit. But does that safely isolate the circuit, like a standard isolator would do. What does BS7671 say about isolation?

 

[mainline]

Ok.

I'm thinking a contactor has a control circuit, which would operate said contactor. Whereby you could isolate the control circuit. But does that safely isolate the circuit, like a standard isolator would do. What does BS7671 say about isolation?

Bs7671 gives guidance on what can be used for Isolation, emergency switching and functional switching.

Table 537.4 60947 contactor isolation = yes

 

[James]

I have not got time to look in depth into it.
however my thoughts, right or possibly wrong as you have pointed out.

An isolator is a means of removing power from a circuit to allow amongst other things, work to be safely carried out on it.
a contactor by its very nature may bring power back to the circuit if it receives power to the coil, this may be from an automatic device like a thermostat or a remote switch.
I for one, would only rely on a contactor for isolation of a circuit i was working on under some very specific circumstances. and also, I have yet to see a contactor that has a means of locking off.

 

[nicebutdim]

Maybe not the wisest place for this discussion.

 

[James]

yes, @nicebutdim I hadn't considered that.
perhaps if anyone wants to discuss it further then a new thread would be better.