Max distance of fcu from appliance

[haptism]

Hi, is there a max distance an fcu can be from an appliance ? Im looking to fit a wall heater on a dedicated circuit; I know the fcu needs to be near to the heater for isolation and maintenance ? I cannot find anything to define "near", in Reg 537.3.2 at least. Anyone know ?

 

[PEG]

This sounds like another case of "suitable" or "convenient",where an actual measurement in meters,eludes us

I have encountered them,placed 1.5M away,and yet through two doors...or 5M away,in the same room,clearly marked.

I suppose if they are positioned to be readily accessed,for the purpose of their use,no probs.

 

[Richard Burns]

I think it is generally considered that within 2m is near, but the intent is that the switch is readily available and obviously associated with the appliance.

Beaten to it by PEG!

 

[westward10]

Ideally it should be local but if it is not it should be identified as to its purpose and have some means for locking it off. Why can't you put it local, is it domestic, commercial and does the heater have built in controls/isolation.

 

[haptism]

There will be x2 timer/fcu's each serving its own heater that are located in two adjacent rooms. The customer would prefer both of the timers'/ fcus' in the one room (located next to the consumer unit) "Local" means of isolation (as in distances) is not defined in the regs (at least i cannot find). Since posting ive found that its not unheard of to have appliance fcu's located away from the appliance, just wondered on any specific regs for this. As long as the cable from the fcu/timer is suitably sized for load & v/d then wouldnt be an issue ?

 

[Midwest]

Don't think regs specify a distance, only recommendation in OSG. Suppose if the FCU would be classed as an isolator, then not being local to the appliance it could be turned on by another, if for example its spurred off RFC as opposed to being on 'lock off 'able own circuit'?

 

[Deleted member 26818]

If these heaters are on dedicated circuits, there's not much point in having the FCU near the CU.
Could just use the MCBs to isolate (depending of course on the earthing system).

 

[westward10]

If you don't wish to use FCUS by the heaters how are you going to make the final connection? Outlet plates, they are not much different to what you are trying to avoid.

 

[haptism]

If you don't wish to use FCUS by the heaters how are you going to make the final connection? Outlet plates, they are not much different to what you are trying to avoid.

Supply is through the wall into the rear !

 

[LED Lighting]

Worked on a house the other day.
Boiler is in an outbuilding outside. Controls and pumps are in the airing cupboard upstairs. FCU is in the same cupboard upstairs.

No means of isolation at the boiler and can't put one in either because there's several switch lines from the control via 1 swa cable.

Only option is put a label on the boiler and fcu stating others location and that complies. Even with 20m+ and 2 locked doors between the 2 locations

 

[Doomed]

There is normally a manufacturers rule that there should be local isolation for the boiler.
In the last mentioned situation I would fit a triple pole switch (such as a fan isolater switch) by the boiler so the gas engineer can isolate it for their servicing.

 

[stephanjs]

Don’t normally reply to these on sites but this is an interesting question I have been asked many times.

1st there is the question of design. How is the appliance being fed from the fcu? Remember that the protection is for the benefit of the cable not the appliance connected at the end.

2nd there is the question of usage. Will the fcu be used for maintenance? The person maintaining the appliance should have total control of the fcu. This excludes to a great extent not being located in the same room. (537.3.1.2, 537.3.2.2 and 537.3.2.4)

GN1 expands on the above a little bit more I believe.

 

[haptism]

Thanks for the late reply, the customer has chopped and changed the original location of the two fcu's/timers; initially they were to be located next to each heater (which are in adjacent rooms) with flex; now he has requested both devices beneath the CU with each supply into the rear of each heater.

The intergrated fcu/timers have already been purchased and he wants these fitted. In my interpretation, as the fcu's/timers cannot be locked off (Reg 537.2.1.5), then they should each be local to each heater.

It could be argued that if timers (without the fcu's) are fitted beneath the CU then this would fulfill Reg 537.2.1.5) as the 16A mcb could be locked off. The heater instructions state it must have an 13 A FCU, and 1.5 flex, but im going to hardwire into the back with 2.5.The heater instructions may be using the old 240v to define 1.5mm flex, its a 3KW heater.

Anyhow I'll put each timer/fcu in the same room as each heater. Its been interesting and learning all the time.