Any electricians in the house?

[mrapbp]

I have a electricery related question as my knowledge is somewhat lacking in this area!

I have just bought a heavy duty treadmill from a company that imports them from the US. I have put it in the garage and every time I plug it in it trips the electrics.

There is a switch box in the garage and a main one in the house and both trip when turning on the treadmill.

It is plugged in to the treadmill with a rather odd looking mains cable I think it is called a IEC C19 cable (looks like a standard kettle lead but with the holes running horizontally rather than vertically) and is fused with a 13A fuse.

So anyone have any ideas why this might be happening?

Cheers!

[Mooky55]

Might seem like something silly - but we use 230v and they use 110v? What is the treadmill expecting? Is it able to accept both voltages?

[mrapbp]

Yea it can accept both, the company that I bought from supplies a lot of kit into the UK so shouldnt be problem.

Originally Posted by Mooky55

Might seem like something silly - but we use 230v and they use 110v? What is the treadmill expecting? Is it able to accept both voltages?

[jwlawler]

Originally Posted by mrapbp

I have a electricery related question as my knowledge is somewhat lacking in this area!

I have just bought a heavy duty treadmill from a company that imports them from the US. I have put it in the garage and every time I plug it in it trips the electrics.

There is a switch box in the garage and a main one in the house and both trip when turning on the treadmill.

It is plugged in to the treadmill with a rather odd looking mains cable I think it is called a IEC C19 cable (looks like a standard kettle lead but with the holes running horizontally rather than vertically) and is fused with a 13A fuse.

So anyone have any ideas why this might be happening?

Cheers!

If it is a voltage issue then you may be very lucky that the trips responded quickly rather than the treadmill going bang. As Mooky55 says, our voltage is about twice theirs so the device would try to take twice the current meaning four times the power (twice the voltage and twice the current, 2 x 2 = 4).

Nonetheless, it is a little surprising that the trip fired since they normally detect an earth leakage rather than excess current due to the wrong voltage. The trip cannot know how much power the device really needs. I guess that it also monitors for a maximum current and responded more quickly that the fuse. 13A fuses do not blow easily. As a kid, I mis-wired an experiment and had a toggle switch across the mains. When I turned it on, the switch exploded but the 13A fuse was fine.

Look carefully at the device for the voltage it expects and whether there is a switch to select the voltage. Let us know whet you find. List any other data such as current (Amps / A), power (Watts W or VA), and frequency (Hz). Many modern devices can automatically switch but mostly small or medium size electronic items (phone chargers, lap top power supplies, etc). I would not expect a high power device to auto-switch. Either there is a manual switch or you will need to buy a transformer (probably a big expensive one for something like that). You may still be unlucky if it insists on 60Hz since a simple transformer won't change that.

It is worth talking to the import company. I would hope that they had checked that the device could be used here and they told their customers of any special procedures or requirements e.g. change the voltage switch or buy a transformer.

[jwlawler]

Originally Posted by mrapbp

Yea it can accept both, the company that I bought from supplies a lot of kit into the UK so shouldnt be problem.

You seem to have written this as I wrote my note. Even if it can accept both voltages, I would still expect it to have a switch. Look carefully at it and its manual.

If the voltage setting is correct then something else is wrong such as a wiring error and a fault in the device. Do you have a multimeter and know how to use it?

[nheather]

As others have said, for an item of that power I would expect a switch to select between 110V and 240V.

Could you publish a link to the seller. We may be able to deduce more from the advert.

Cheers,

Nigel

[Mr Incredible]

Originally Posted by jwlawler

If it is a voltage issue then you may be very lucky that the trips responded quickly rather than the treadmill going bang. As Mooky55 says, our voltage is about twice theirs so the device would try to take twice the current meaning four times the power (twice the voltage and twice the current, 2 x 2 = 4).

V=IR

For the same resistance in the motor, twice the voltage would half the current, not double it. 150W is a 150W motor whether it runs on 110V or 240V.

If the unit is designed for dual voltage usage and its tripping the mains, that sounds like an earth leakage fault. Contact the supplier ASAP.

[jwlawler]

Originally Posted by Mr Incredible

V=IR

For the same resistance in the motor, twice the voltage would half the current, not double it. 150W is a 150W motor whether it runs on 110V or 240V.

If the unit is designed for dual voltage usage and its tripping the mains, that sounds like an earth leakage fault. Contact the supplier ASAP.

Not as I see it. Let's take a particular example. A 1100W motor expecting 110V. So, P = VI (Power = Voltage times current) tells us that it expects 10A. V = IR tells us that the resistance must 11 Ohm. Now connect the motor to 220V (*), V = IR tells us that 20A will flow. P = VI tells us that the power is 4400W.

(*) Slightly wrong but it makes the arithmetic easier.

If the device was switchable then the switch would change the resistance to achieve the same power. To get 1100W from 220V means 5A so the resistance would have to change to 44 Ohm. This could be done by having two internal 22 Ohm components in parallel (hence 11 Ohm) for 110V and in series (hence 44 Ohm) for 220V.

The motor may be intended to be 1100W but does not mean that it will magically be so if connected to the wrong voltage. Get a US 100W light bulb and plug it in here, it will not emit 100W of light (and heat). It will briefly output 400W before going bang,

In fact, it is all rather more complicated since motors (unlike light bulbs and heaters) are not simple resistive devices but I think that it will be nearer to my description than yours.

[nheather]

@Mr Incredible

No it wouldn't

V = IR

If V doubles and R stays the same then I has to double to make the equation balance.

Let's say R = 10 ohm

V =110 V >> I = 1.1 Amps

Now let's put V=240

I = 240/10 = 2.4 Amps

The power supplied to the motor does in theory go from 121W to 576W but in practice something would burn out before the motor could deliver that power.

But I agree that assuming the voltage is selected correctly (or auto selects) then it sounds like an earth leak.

Cheers,

Nigel

[Mr Incredible]

I'll get me coat.

[mrapbp]

Now now boys lets keep this relevant/happy

[jwlawler]

Originally Posted by mrapbp

Now now boys lets keep this relevant/happy

I think that it is relevant and happy. I have not noticed anything nasty. If anything of mine did sound nasty then I apologise, nothing was intended to be so.

Anyway, are you getting anywhere towards solving your problem?

[nheather]

Yep sorry, no offence intended.

So back to topic. the problem is either

1 - There is a switch, ususlly near the mains socket to switch between 110VAC and 240VAC.

2 - You have an earth leakage fault.


If it is the first then it should be good news and just a matter of flicker the switch over (did they supply a lead with a UK plug or did you have to fit the plug?)

If it is the second then bad news - the item has a fault which is would be very difficult to diagnose over the internet.

Cheers

Nigel

[mrapbp]

I was only joking m8, no drama!

Thanks for all the suggestions so far, will have a look when I am back at home.

Originally Posted by jwlawler

I think that it is relevant and happy. I have not noticed anything nasty. If anything of mine did sound nasty then I apologise, nothing was intended to be so.

Anyway, are you getting anywhere towards solving your problem?

[jwlawler]

Originally Posted by nheather

Yep sorry, no offence intended.

So back to topic. the problem is either

1 - There is a switch, ususlly near the mains socket to switch between 100VAC and 240VAC.

2 - You have an earth leakage fault.


If it is the first then it should be good news and just a matter of flicker the switch over (did they supply a lead with a UK plug or did you have to fit the plug?)

If it is the second then bad news - the item has a fault which is would be very difficult to diagnose over the internet.

Cheers

Nigel

Ditto here. Talking through diagnosing and fixing an earth leakage would be a challenge and probably inadvisable. Anyway, if a new item has such as fault then you ought to return it. First check that you have correctly followed any relevant instructions and, if you have, then complain.

A theoretical but probably unlikely possibility is that the earth leakage is because the insulation cannot cope with the higher UK voltage. The insulation may be able to cope with 110V with no significant leak but not 240V. However, I would expect that the safety margin on the insulation to be large enough to cope.

I just remembered that some high power US devices do expect 220V. Houses there often have two out of phase 110V feeds. Simple lower power devices use neutral and one of these. Higher power devices use the 220V between the two feeds.

Can you give us some more specs? Yet another possibility is that the device just wants too much power. A UK socket is rated at 13A which is a little over 3000W at 240V. The fuse in the plug should enforce this but they are typically lousy, other things (e.g. the device itself) often blow first to protect the fuse. Your switchboard should be restricting the current for the ring but it is probably allowing 30A which is over 7000W. Note that I am not saying that you should take 7000W from one socket, just that the switchboard probably won't be able to tell the difference between one socket taking 7000W by itself and several taking below 3000W each but a total of 7000W.

If the power is above 3000W then it will need its own circuit as cookers and showers normally do. For this, you will should use a professional electrician.