what code help

[jamie-spark]

Hi chaps. First of all thanks in advance for any input.

I have had a friendly dispute with another electrician on what code this should receive.

Scenario
it is residential student accommodation. There is 1 main boiler with switch wires going to 4 zone valves (1 in each flat).
The boiler switches through the zone valve end switches.
The motor supply to the zone valves are controlled through a separate programmer in each flat (as the there are 4 flats within the block) these are all off different phases to the boiler so there is 400v present. Now there is no 1 means of isolation for this dual supplies going to each valve with no warning label.
What code would u give it for the 400v present

4 programmers
4 water tanks?
4 solar/thermal pumps

 

[daveb1]

As i am currently studding for my 2395 i will be eagerly watching this, i would say C2 its only dangerous if someone/electrician is working on it?

Like i say i am not saying this is right because im am obviously not quilefied to say but this is my thoughts

Dave

 

[Silly Sausage]

That's got be a 2.

 

[Richard Burns]

Electrically it sounds somewhat unconventional for a domestic situation but still compliant with BS7671.
I think that the only problem is lack of labelling which I would class as C3.
If it was labelled there would be no practical problem and I cannot see this as being any worse than having any other piece of equipment that has an unexpected arrangement, but is still safe.

 

[ackbarthestar]

If you are saying that each flat is on a separate phase and each zone valve is controlled by a separate single phase programmer then the only concern might be the fact that there is no single point of isolation, or a place where all the CH circuits can be isolated, when maintenance work is required to the whole CH system. and would mention this with a C3

Otherwise if there two phases entering each flat, I would say a C3 as there is no prior warning to some unsuspecting sparks doing a bit of inspection in the future.

Something like this does bring it home that an inexperienced or/and unskilled person could end up in something more than a pickle, over code something that isn't directly or potentially dangerous unless its fiddled about with.

 

[Guest55]

whats the danger to the user of the equipment ?

very little i'd say , thus C3.

ignore the C2 drama queens.

 

[MDJ]

whats the danger to the user of the equipment ?

very little i'd say , thus C3.

ignore the C2 drama queens.

Even an old 4, 3 at most, surprised 2 has been mentioned

 

[Dizzy_Maskell]

Yes can't believe a new 2 considered fail the install for this????
A new 3 or old 4 is the order if the day

 

[jamie-spark]

Thanks a lot guys.
I too said a C3. The other guy thought it should be a 2.

More to follow chasing my tail the now

 

[jamie-spark]

If you are saying that each flat is on a separate phase and each zone valve is controlled by a separate single phase programmer then the only concern might be the fact that there is no single point of isolation, or a place where all the CH circuits can be isolated, when maintenance work is required to the whole CH system. and would mention this with a C3

Otherwise if there two phases entering each flat, I would say a C3 as there is no prior warning to some unsuspecting sparks doing a bit of inspection in the future.

Something like this does bring it home that an inexperienced or/and unskilled person could end up in something more than a pickle, over code something that isn't directly or potentially dangerous unless its fiddled about with.

Yes. Boiler is on L1, flat 1 is on L3 and a sub board has been installed on L2 supplying flat 2,3 and 4 heating controls. Programmers control zone valves and there is the boiler switch controls going to the end switch inside the zone valves. ( hope this makes sense)
I too say it should be a c3 as of reg 514.11.1 due to the dual supplies going in

 

[jamie-spark]

I have been up to my eyes in it, so it's took a while to get back.
The other electrician wanted a c2 due to the 400 v at the zone valve. But he has come round now.

I know it's not required but if we do remedial works I would also be tempted sticking a 400v label on it. (514.10.1)

Thanks again. Top quality info from the respected members