Electric panel heaters..??

[sparkyjohn1]

I recently had another spark ring me up , about a job i completed late last year.Ranting that I havn't installed the heating circuit correctly, and i should re-visit to property to correct it.

The property didn't have a gas supply, so was asked to supply and Install a heating solution. ( electric rads / heaters etc.)

I have included a picture. ##best schematic diagram i could do on microsoft paint.##

This is how i did the job,, please tell me if you can find anything wrong with it..

Only thing i can think of is that the IN-LINE STAT, maybe borderline regarding max current draw,,,rated 16amp. but that is about it.. everything else seems o.k,??

Please let me know if you have any feedback..
thanks

 

[tazz]

Old school....so practical designs, always safer.....rcd are not the be all and end all of safety....design as it were a bs88....and you still have the same disconnection time if not better, with an rcd

 

[Marvo]

The MCB in the CU isn't there to protect the devices on the circuit, it's there to protect the circuit itself. The way this is configured the actual supply circuit ends at the point it connects to the thermostat. Surely the supply circuit should end as a point of isolation such as a dp isolator or an FCU?

 

[tazz]

Exactly, you would want the maximum return fault current as possible, which would be distrupted by a failing device in the middle...ie the stat

 

[Marvo]

I like your thinking Tazz, I'd be interested to see if the t/stat has a kA rating equal or higher than the PSC current.

 

[tazz]

This is the thing abaut new regs.....they may have rcbo`s and rcd`s.....but if you go back to the 15th (which was a bit over the top on earthing...think Cockburn was on the committee) the system was the same, low impedance..high fault current, with quicker disconnection time...the standard was still minimum of 0.5 secs on a wired fuse

 

[Badged01]

The MCB in the CU isn't there to protect the devices on the circuit, it's there to protect the circuit itself. The way this is configured the actual supply circuit ends at the point it connects to the thermostat. Surely the supply circuit should end as a point of isolation such as a dp isolator or an FCU?

Correct, and the 40A will adequatley protect the 6mm circuit cable feeding the stat. The debate is around the 40A C/B not protecting the 16A rated stat which it wont on face value. However, the nature of the circuit loading (heaters) is such that the overload current should not exceed 16A -- there or thereabouts! Fault protection should be covered by the RCD and the method of installation reducing its likely hood to a minimum -- setting aside the issue of RCD's failing / what we used to do when I was an apprentice etc.... ( I dont want to get into a debate on RCD's as there are plenty of arguements on other threads ref this!)

As for an isolator/FCU, I dont see any contravention of a reg in not having one for this circuit layout?

 

[tazz]

Can not disagree with any thing in your last post, other to say the stat is a hinderance not a breach

 

[Badged01]

Not suggesting is any way that I would design the circuit like this, just that it is an "alternative" way of doing things!

 

[tazz]

Im quite sure you wouldn`t...lol