18 kw inline pool heater

[tootsie123]

hi

have recently purchased house with 18 kw inline pool heater. have worked out need a fuse rating of 78 amps. had edf change main fuse in house to 100amps and understand will need to use economy seven for heating.

question is ... am unsure weather to install a contactor or an MCB (if so should it be type C or D. am pretty confused as electrician suggested installing 3 phase and the contactor seems expensive.

Thanks

 

[Steve]

EIGHTEEN KW???

You NEED 3 phase for that. NO question. You'll brownout half the neighbourhood when that thing pulls in on a contactor otherwise. Its just too much to put on one 100 amp service.

Why was this installed yet not wired up? (Oh I know the answer to this - no sparks would touch it without 3ph)

And a contactor and MCB do different jobs. You need BOTH, whatever happens.

 

[RF Lighting]

I'm not sure you quite understand the implications of such a big load in a domestic property.

First of all you will not get an MCB capable of supplying a load of that size.


Secondly you without question need a 3ph supply.

thirdly you need a contactor to switch a load this size, and that will not be especially cheap.

 

[ricicle]

The cost of the contactor will be small potatoes compared to the cost of installing 3 phase to your property.
It may be possible to downrate the heater by re-configuring the connections, but this will affect the heaters ability to heat up/maintain heat in the pool.
As has been said above you really need a 3 phase supply for this and a competant electrician who is experienced in 3 phase control to boot.

 

[breezer]

heat the pool by gas, its cheaper

 

[Lectrician]

18kw........do not envy your lecky bill if you do pay out the thousands to get this installed!

 

[Softus]

... am unsure ... am pretty confused ...

 

[big-all]

18kw........do not envy your lecky bill if you do pay out the thousands to get this installed!

sorry to highjack your thread

can you e mail me please lec

 

[jayc]

I'd ditch the existing heater and go the way of a heat pump. Will most likely be cheaper than getting a 3 phase suppy and use a fraction of the power.

 

[fattony]

Having just read this post (not trying to hijack) my company is currently looking at a pool which requires a 50Amp MCB, I expressed concern that I thought this was to big a load for the normal supply, am I being over cautious?

 

[Adam_151]

Having just read this post (not trying to hijack) my company is currently looking at a pool which requires a 50Amp MCB, I expressed concern that I thought this was to big a load for the normal supply, am I being over cautious?

Depends what else is there, if there is no electric cooker or shower then possibly not, but as a load drawing a high current for possibly hours on end, I'd perhaps recommend its supplied from a separate switch fuse( either BS1361, or just a DIN enclosure fitted with DP switch and B50 and the appropiate connections made), not off the normal CU

 

[fattony]

There are 3 showers I think but believe they are power showers not electric showers. What ever way you look at it its 50% of your supply for the pool, I know when you apply diversty an average house hold does not draw anywhere near 100Amp, but lets be honest an average house doesn't contain a pool

 

[ricicle]

If you have a 100A supply and the pool heater draws 50A then you are obviously left with 50A.
You would be hard pushed to find a house that will draw 50A for long periods.With careful/responsible usage (eg timeswitches for nightime only) then I don't see this situation as too much of a problem with a properly installed control system.
As for the leccy bill, that's another thing!!

 

[fattony]

I think your right, Im going to suggest a timeclock switching a contactor or similar.