How to create a 32A 110v supply?

[mm289]

Hiya,

got hold of a 1.5/3 Kw infra red heater that I want to use in my workshop for heating and paint curing.

It is rigged with a 32A socket and obviously can't run off my normal 110v portable transformers.

My ring main is protected by a C32 RCBO and I also have a seperate switched spur direct from the distribution protected by a C16 RCBO (use for my ramp but could uprate the RCBO)

So, whats the best way to get a 110v supply for the heater (which I would guess needs to be rated at 4kVA continuous)

Thanks,

MM

 

[brightspark]

Hiya,

got hold of a 1.5/3 Kw infra red heater that I want to use in my workshop for heating and paint curing.

It is rigged with a 32A socket and obviously can't run off my normal 110v portable transformers.

My ring main is protected by a C32 RCBO and I also have a seperate switched spur direct from the distribution protected by a C16 RCBO (use for my ramp but could uprate the RCBO)

So, whats the best way to get a 110v supply for the heater (which I would guess needs to be rated at 4kVA continuous)

Thanks,

MM

buy a second hand 4kva 110 transformer big ££££

 

[madkayaker]

Big 110V transformer is the only way forward. A 5.5kva will pull about 20A on the 230V side. The inrush can be a problem sometimes my 3.3KVA will happily trip a 32C where as my 5.5KVA is happy on a 32B

 

[Shox Dr]

Ask around the local hire companies, they might have one that has a damaged casing, a bit of Fibre glassing and bob's you uncle

 

[mm289]

Thanks guys,

thats what I was afraid you might say

So a "cheap" 32A 110v unit isn't that cheap really as it costs a fortune to get the supply

WIll start scouring fleabay etc for a suitable transformer, guess I am looking at one of the big 6+ outlet jobs rather than the small 2 outlet units.

BTW, whats the difference between a 32B and 32C RCBO?

Thanks,

MM

 

[the snooper]

would 2 smaller 110 transformers run in parallel work same voltage more amperage

 

[tigler]

Several smaller 110V transformers could be paralleled to give the required power.

 

[dannyp]

you chould just wire the heater eliments up in series
then it wold be 3k or 3kw and 220v

 

[rtbcomp]

Be very careful when connecting transformers in parallel. The outputs MUST be in phase. Also it's best to use identical transformers so the voltages are exactly the same, otherwise you get power losses and unequal power sharing between them.

 

[the snooper]

if you use the same supply and phase they cant fail to be in phase

 

[rtbcomp]

you chould just wire the heater eliments up in series
then it wold be 3k or 3kw and 220v

That would be my preferred method. Just be careful if there are any fans or other bits that run off 110v, these would have to be connected across one of the elements if they don't take too much power, otherwise powered from a small transformer.

 

[rtbcomp]

if you use the same supply and phase they cant fail to be in phase

As long as they're identical units and nobody's swapped any wires around inside.

 

[the snooper]

if that can be done then its by far the best method

 

[tigler]

would 2 smaller 110 transformers run in parallel work same voltage more amperage

Didn't see your reply before I posted mine !!

 

[the snooper]

thats life we have all been there before

 

[Hitch]

Whats the score inside a 3.3kva box..cant remember.... is there a single wire from the actual transformer, that then splits into 2 smaller ones going to the 16a outlets......?
Just swap the 2 16a sockets for a 32a socket...if thats the case.....?

 

[the snooper]

as long as the transformer is constant rated at 3.3kva and the heater is a resistive load

 

[mm289]

Glad I have tickled the grey cells on a Sunday afternoon

I only have 1 x 110 transformer although these are pretty cheap so i could get second, would have to convert to 32A plug though ........

The idea of wiring the heater elements in series sounds interesting as it isn't a fan unit - actually its one of these http://www.machinemart.co.uk/shop/product/details/clarke-devil-371p-quartz-halogen-infra-red-hea

Presumably I would loose the option of switching the bars on individually which is no great loss.

Is the logic that if they are coupled together you are drawing 220v so can run from a standard supply (bit of a while since I did physics )

Cheers,

MM

 

[the snooper]

yeah wired in series it will run from 230v on 1 standard 13 amp plug but will be a fixed 3kw heater
but depending on how you wire it and switches you could use your 110 transformer to run 1 element at 1.5kw if you needed to

 

[madkayaker]

Most of the 3.3kva transformers are "power tool rated" so 5 on 15 min off. The heating element could very easy be run off 230v and the fan might have to be 110v. 10kva transformers are quite cheep as the bought for a building job then flogged afterwards but check that it's 230v input. Some of the ones flogged as 400v or three phase when you check the data plate are really 230v but the seller doesn't know what they have! could you not just get a 230v heater might be cheaper than the hassle.