FCU off a ring.

[SafetyFirst]

Hi folks i'm new here and must say it looks a fantastic site to gain some professional info from! Right i'm a qualified spark but we all have our own idea's and ways of doing things. I have a relative who owns a bakery and they need to install a water heater (3kw) in the storage/handling area for hygene reasons.
The ring is fed from a 3 phase board and is RCD protected, it has no other spurs anywhere on the circuit but as yet do not have the information of the actual total load at any one time. I know they have a couple of fridges plugged in at all times, a coffee machine and possibly a griddle of some sort.

I know the easiest way would be to spur from the nearest socket on the ring down to a local FCU protected via a 13A fuse and from there to the heater. However i wouldn't want nuscence tripping from overload so do folks reckon i ought to stick this 3kw water heater on a seperate circuit via a 16A RCBO fuse?

 

[Spudnik]

Hi Mr First and welcome.

Funny you should post this as i have just come back from an exact same thing.

3KW water heater via FCU off 20A RFC

Fridge, radio and various fan heaters all plugged in and working and pop goes the MCB.

Now, if this had been on a 32A RFC then i dont think it would have been a prob, but i RECOMMENDED a separate 16 A from the CU as it was reasonably close.

Anyway back to you original question, there is no reason why you cant spur off the ring, providing you think loading wont be an issue.

 

[Notsosmart]

Depends on whether the relative has short arms & deep pockets

I think you have supplied your own answer; Ideally you would run in a new circuit, but as this is a heater for hand-washing then how often will it be used along with the full capacity of the other appliances? If you think that there is a likely-hood of over-loading then you should be pricing for a new circuit.
If the Griddle is on the same circuit then this is most likely the highest load (maybe look at installing a new circuit for this also)


Thats just typical Jason Once again your quicker on the keyboard!

 

[Spudnik]

Thats just typical Jason Once again your quicker on the keyboard!

Gotta get up REAL early to catch me

 

[SafetyFirst]

Thanks Jason and NSS! I think i'll go with the new circuit method. 16A RCBO protected run in 2.5mm radial to a Switched FCU (13A) then flex down to the water heater. It's about to get a PIR check in any case so i'd like to be certain its gonna pass without any recommendations listed on it! The bakery's been up and running for over a year now so there's no issues regarding the griddle but yeah i thought that would be the main load user so i think it's best i don't push my luck!

Btw folks i'll make another few threads on here shortly as i'm about to start a 2391 course so i'll be after more of your good advice before too long, nice to meet yers both anyhoo!

 

[pennywise]

I would put it on a 20a double pole switch instead of the fuse spur.

 

[SafetyFirst]

I would put it on a 20a double pole switch instead of the fuse spur.

Yep thats a better idea thanks for that.

 

[Jason Smith]

Does the water heater actually hold any water, if so how many litres

 

[pennywise]

Over 15 litres and it's got to be on it's own supply.

 

[Des 56]

Over 15 litres and it's got to be on it's own supply.

pennywise
I was reading the thread from the top with that in mind,got to yours and, I got no more to add

 

[SafetyFirst]

Does the water heater actually hold any water, if so how many litres

Aint seen the water heater they've bought as yet but they say it's definatley 3kw i'm definatley putting it on it's own independant cct now anyways cheers, i'll let yers know when its done lads!