Plinth Heater fuse size

[dartagnan]

Im fitting a Plinth Heater in the kitchen with a double pole idolator switch, what amp fuse rating should i buy.
Its has 3 settings. 800w, 1500w 2400w

Thanks

 

[ban-all-sheds]

The FCU will come with a 13A fuse, which will be fine.

Power = Voltage x Current.

 

[winston1]

Power = Voltage x Current.

Only true for DC or unity power factor AC, but as this is a heating load I'll let you off that one.

 

[dartagnan]

Thanks Ban All Sheds, so in that case couldnt i just put a 13amp plug on it. I thought the max load was about 2000w before needing to fir an double pole switch?

 

[ban-all-sheds]

Thanks Ban All Sheds, so in that case couldnt i just put a 13amp plug on it.

You can, but that would be a really tacky way to supply a built-in fan heater.

I thought the max load was about 2000w before needing to fir an double pole switch?

I'm surprised you've never seen portable 3-bar electric fires.

 

[dartagnan]

It would plug straight into as socket at the back of the cupboard that the extraction fan uses. Well out of sight.

 

[ericmark]

Assuming the heat is supplied by electric yes 13A fuse, however hydraulic heaters only take power for the fan from the electric supply, three fan speeds give three heat outputs, for that type 1A would be enough.

One would normally expect the elements in a total electric to be all the same, so 800, 1600, 2400 since with yours the centre output is only 1500 watt I just wonder if all electric or if connected to central heating?

 

[winston1]

Assuming the heat is supplied by electric yes 13A fuse, however hydraulic heaters only take power for the fan from the electric supply, three fan speeds give three heat outputs, for that type 1A would be enough.

But the fuse is to protect the connecting cable not the fan which will be internally protected (either by a fuse or heat sensor). So once again a 13 amp fuse is OK. Elsewhere in Europe it would be protected by a 16 amp MCB without a problem.

 

[ericmark]

But the fuse is to protect the connecting cable not the fan which will be internally protected (either by a fuse or heat sensor). So once again a 13 amp fuse is OK. Elsewhere in Europe it would be protected by a 16 amp MCB without a problem.

There is no internal fuse in my Myson, and as a fixed appliance there is no need for the manufacturer to fit one, they can simply state in the commissioning instructions this appliance should be protected by a 3A fuse, I will agree with a portable appliance it must be supplied with a 13A plug with a fuse selected to protect the cable, but this does not apply with fixed appliances, it is common to find boiler manufacturers state 3A fuse must be used.

Yes else where in Europe they do have different fuses, the typical bottle fuse has a base which can be selected so impossible to fit a 16A fuse instead of a 4A or 6A there is a special tool to remove and replace the base and yes they cheat just like us and smash the base so you can fit a larger fuse, but be it a MCB or fuse in Europe fixed appliances can have smaller than 16A fuses fitted.

I personally did not like the Siemens bottle fuse as the switch is after the fuse not before it, so with the larger fuses it does not comply with British IP rating rules. And if a fuse breaks leaving the nose cap behind it is hard to clean without the proper base removal tool.

However it is not very likely that it is a water powered unit, more likely to be all electric, however without knowing for sure one should alert the poster to the fact if connected to central heating then likely the manufacturer will stipulate 3A and likely it would run A1 with a 1A fuse, we tell others not to assume and I am in this case not assuming all electric until told it is.

 

[JohnW2]

One would normally expect the elements in a total electric to be all the same, so 800, 1600, 2400 ...

Indeed, so I suspect the OP's "1500" was probably a typo.

Kind Regards, John

 

[winston1]

There is no internal fuse in my Myson, and as a fixed appliance there is no need for the manufacturer to fit one, they can simply state in the commissioning instructions this appliance should be protected by a 3A fuse, I will agree with a portable appliance it must be supplied with a 13A plug with a fuse selected to protect the cable, but this does not apply with fixed appliances, it is common to find boiler manufacturers state 3A fuse must be used.

This is because someone does not understand what a fuse is for. Ask the manufacturers what they do or state when they sell the same boiler in Europe.

 

[ericmark]

I made the mistake of thinking when the manufacturer stated a xxx fuse should be used to protect the equipment of fitting a MCB. When the item failed, the manufacturer came to repair it, and charged our company for time and material because I had use a MCB instead of a fuse. I was told in no uncertain terms, with fixed equipment the manufacturer can stipulate how it is to be installed if we want to take advantage of warranty offered. They did back down after it was pointed out their guy had commissioned the equipment so using a MCB instead of fuse should have been raised then.

It turned out the fuse recommended was a special semi-conductor fuse, which protected the solid state relay if an element when short circuit, so good reason to fit a fuse.

The point was made if they fitted the fuse inside the equipment there was a heat problem from the fuse, and where it would have been fitted was hard to assess, so having the fuse external was sensible, we could swap the heater and change the fuse far faster with it external to the equipment.

I do see the point with a standard FCU there is nothing to stop one fitting 1, 2, 3, 5, 7, 10 or 13 amp fuse, there is no device in the British system to stop one fitting a fuse which is too large, unlike the rest of Europe, and it is in charge of an ordinary person so it needs to be type tested. However even inside a boiler where a 500 mA fast blow fuse is fitted, even in an area where really only a gas safe registered person is allowed to enter, in real terms the user can still open up the boiler and replace it with a nail. So at some point we have to trust the user to use some common sense.

In this case I really can't see a heater being supplied without instructions as to what supply it requires. I am sure with a little reading some where it will state the fuse size to use.

 

[EFLImpudence]

It turned out the fuse recommended was a special semi-conductor fuse, which protected the solid state relay if an element when short circuit, so good reason to fit a fuse.

You would think they could fit one, then.

The point was made if they fitted the fuse inside the equipment there was a heat problem from the fuse,

Oh right, that must be an insurmountable engineering problem.

and where it would have been fitted was hard to assess,

Just of the top of my head - fit it somewhere else, perhaps.

 

[winston1]

even in an area where really only a gas safe registered person is allowed to enter,

There is no such area if you are working on your own equipment. (Though you are not allowed if working for someone else).

 

[ban-all-sheds]

There is if you are incompetent.