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I have an immersion circulator that has an American plug socket on it.
The model is a old west german B.Braun Thermomix 1420, and on the back it label of the device it says 120V.
(see attached pictures)
The manual for the device says:
RIF: 300V at 500kHz
Electrical connection: 220V 50-60Hz, 110 V, 220 V, 240 V, 50-60 Hz
The manual also says it uses upto 750W (as it can heat a bath of water relatively quickly, but I presume once its up to temperature maintaining it requires less W).
Does anyone know if I need to buy a huge step-down transformer 240 to 120V that can handle 750W, or is the manual saying I can use it at 240V?
A very helpful chap in Maplins said usually heating element would just draw the power they need so a simple plug adapter would suffice, but since this also contains a pump and thermometer and circuit board I think this is not the case.
Thanks!
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did someone say they needed a transformer?
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igmc
the manual is probably generic and that one is set up for 120V. There might be a switch inside but wouldn't want to mess with anything if you are heating water.
not sure I would trust what someone from Maplins said. Get something that can easily cope with the full rated power and then some.
OR get a unit built for use in the UK.
edit: just spotted the internal transformer says 120V so looks like it could be built with a single stage transformer that is only 120V so not switchable.
the manual is probably generic. it states that the voltage on the unit it 120V
so a step down transformer 240v - 120v is needed 1KVA would do the trick.
The transformer may have different taps on the mains winding for 240v or 120v, and it's currently configured for 120v. Accessing these taps may be a simple case of changing a connection on a connector block or spade terminal, or you may have to use a soldering iron. If this is the case the manual should have some kind of electrical diagram, or there may be one on the transformer itself if you can removing the casing to have a look. In any case if you're not confident with electrics it may be best to use a step down transformer or get a sparky in.
there is indeed an electrical diagram in the manual, it states the "transformer winding is in motor"
the main motor within the unit is for a pump to circulate the water as far as I can tell
its hard to get at right in the middle of the housing though so diffucult to take a good look at
there is this part in it which has 250V marked in it...do you know what it is?
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That will be a capacitor.
with a voltage rating of 250V - ie so it can be used in versions tha run at 230V.
Seriously though, I don't mean this in a nasty way, but if you don't know that is a capacitor I really don't think you should be messing with something powered from the mains. Hook it up to an external transformer or pay someone who knows what they are doing and can test it afterwards.
on another note...what do you actually want to use if for? I presume it's a heater unit from a laboratory water bath from the looks of it. 750W is not actually that powerful so it can only be for small quantites of water so you should get a transformer that can cope.
As for consumption when the water is at temp - it depends if it is an intelligent control that modulates the power - I suspect not. In which case it will probably just turn the element on and off when the temperature goes above/below a pre-set so it will draw the rated power when on. Something like a self regulating heating element will change resistance as it reaches it's design temp but they are more recent and polymer based.
I'd be concerned that running a 120V heating element at 240V risks it overheating and/or the insulation breaking down as it'll be producing twice its rated power.
I can't quite make it out from the pictures but it looks like the transformer is also part of the motor so changing that for a different winding one is probably a no-go.