Ariston water heaters

[MAD MAINTENANCE]

Hi all,

I want to install a Ariston Europrisma undersink water heater 3kw - 15lt. The testing and certification will be done by someone else. This is a great opportunity for me to gain some much needed experience as I am only a little way through my course and I have only helped out on a few other installations. I will have comfort in knowing that someone is going to check it over so this is good.

I have worked out that I need a mains supply with 13 amp together with a Heat resisting 3 core cable of 1.5 mm,

There is a fused spur unit in the room,

Can I change the FCU from a flush to a mounted unit then run my cable from that to a 13 amp double pole fused isolating switch then from there to the heater?
What trunking shall I use? ( It will be on show )


Sorry for the amateur talk guys, :wink5:

Cheers,
Dan,
Mad Maintenance.

 

[polo1]

Follow the manufacturer's installation instructions. For a fixed load like this I would consider a dedicated radial with appropriate s/c and o/c protection. Assume it's not going into a "special location"? YT2 or equiv if trunking required.
Regards.

 

[MAD MAINTENANCE]

Thankyou for the reply.

I just downloaded the manual and it reads,

A mains supply of 240 Vac 3KW (13 amps) is required
Heat resisting cable round 3 core 1.5 should be used to connect the supply through either a 13 amp socket to BS 1363 or a double pole fused isolating switch with a contact seperation of 3 mm minimum on each pole.

would it still be ok to use the FSU though?

Thanks mate

 

[polo1]

OK, the MI appears to be offering either a (local) fused connection or DP isolation...mmm. If going for the local FCU then I would be looking to see what other loading is on that circuit, and only if I thought the additional/new load was going to be ok, would I use it. If you do go for the FCU, then I agree, with 1.5mm, you might be better going for a pattress and gland.

Depending upon just how difficult/costly it was going to be, my preference would still be a dedicated radial on a 16 breaker (or RCBO/RCD if required).

Yeah, the BGB and OSG are not exactly top bedtime reading, but essential if you want to do the job properly, safely etc!

Regards

PS - if going for a dedicated radial, then this circuit should be "designed" by a qualified spark, taking account of all appropriate design factors - route, VD etc

 

[MAD MAINTENANCE]

Thanks,

Ok what i will do is workout what else the FCU is feeding and workout if adding the heater will create any problems.

(It is a W.C so i have no bath or shower but only basins and toilets and hand dryers)
Maybe its likely the FCU is there for the hand dryers?

If I do have to go the route of a dedicated radial them yeah I will Get A qualified spark to design it.

Or maybe it would be a nice challenge for me to try to design the circuit and get it checked out before starting.

thanks,
you been a great help.

 

[polo1]

No worries, but just to be clear, the FCU can only supply your new heater (or some existing appliance). If the existing FCU is already supplying something, then you will require an additional one, circuit permitting.

And yeah, try out designing a new circuit just for the practice.

Regards.

 

[MAD MAINTENANCE]

Yeah I will add an additional FCU if the one there is already used (circuit permitting).

Thanks again

 

[MAD MAINTENANCE]

Sorry to go on but I just want to see if this is ok. If the Existing FCU is already supplying something, which is very likely, can i do this?

Add a new FCU (13amp) to the live point of the existing FCU and use that to supply the heaters. They could be individually isolated for maintenance etc...
(As long as the Volt drop and so on works out ok)

If I can do this where out of habit would you say the new FCU would be best positioned?
P.s I wont bug anymore.
Many thanks
Dan

 

[Edd]

The FCU your thinking of coming from could be a radial, that for argument's sake supplys a hand dryer and is a 16amp radial.. say the hand dryer is around 2 kw then your looking at close to 10 amp already taken. you wont be able to spur off such a circuit.
You need to know what the FCU your looking at does and what kind of circuit its supplyed from..


as for bugging dont worry this kind of question is what the forum is about to help people and inform and learn..

 

[Edd]

If the existing circuit is a radial in 2.5mm cable then no you wont be able to use this circuit. If its a ring and the only item on it is the hand dryer ( very much doupt it) then you could use it. 15ltr is a point that the OSG says that it should be on its own dedicated circuit.
(others point me right if im wrong here please).
your only real option is a new circuit. see whats involved plan a route design the circuit, make sure you have spare ways in the board etc.. chat too the person whos gona cert it, as im sure you could work it under his experiance. hope these ideas help

 

[MAD MAINTENANCE]

The exisiting FCU turned out to be a spur from the ring and had a hand dryer coming out from its live side into its own FCU. I replaced the exisisting FCU with a new one as it looked quite old and the New one I new could handle it. I used the switch wire side to connect my heater and fused it with 13 amps. As reccormended by the installation manual I done that and used heat resisting cable round 3 core 1.5 mm. they got there in house sparks to test it and he has said I have to use twin and earth and an isolating switch needs to be next to the heater and I have to rectify it.

Twin and earth for the electrical supply to a water heater? Surely not.

Isolating switch next to heater? This would be inside a vanity unit / cupboard and next to a water heater so surely not.

Am I just that barking up the wrong tree?

 

[UNG]

When working blind with no photos or drawings it can be difficult to understand what you are doing and make a constructive comment the fact that a spark has inspected your work and suggested corrective work was needed then there is a good chance it does. I would suggest if you are looking for some one on here to provide bullets to shoot that spark down then you may be unlucky

 

[telectrix]

from the FCU use T/E to a D/P isolator, then flex to the heater. as said previously, i would prefer it to be on it's own 16A radial.

 

[MAD MAINTENANCE]

I would suggest if you are looking for some one on here to provide bullets to shoot that spark down then you may be unlucky[/QUOTE]

Like i said am i barking up the wrong tree?

I have just read some of your comments on other post and you are so negative, Chill out where are not all ****s

 

[MAD MAINTENANCE]

from the FCU use T/E to a D/P isolator, then flex to the heater. as said previously, i would prefer it to be on it's own 16A radial.

Thanks yeah I will do that, Maybe thats what he ment. I did actually buy what I needed to do that but someone I was working with convinced me it would be ok straight from the existing FCU and use that as the isolator, Grrr. I no a dedicated redail would be the best option but its not what they want.

Thanks for the advice