20amp FCU or higher?

[sparkwright]

And a switch rated around 30-50 amp.

 

[kai]

Is the American appliance safe to use on a 240 volt supply, having been designed for a 110v supply in mind?

 

[Iggifer]

Is the American appliance safe to use on a 240 volt supply, having been designed for a 110v supply in mind?

He said american style. Not actually american. Plus the nominal voltage in the US is 120v

 

[Adam_151]

Its probably actually designed for 220v.... Larger fixed appliances (cookers, dryers, washers and air con, etc) are normally fed from both 'hots and no neutral. It would be built with the expectation that there would only be 110v between live and ground though.... so if there are any EMI filters etc added which connect to earth they may be underrated, it would also be expecting 60hz and not 50hz which might mean motors run hotter.

Although, if it stats 2.5mm² cable in the manual, it is probably not actually intended for the US domestic market at all....

 

[Spark123]

Extract from instructions

This dryer is supplied without an electric
cord and plug. It must be connected by a
competent electrician to a single-phase
electricity supply at the voltage shown on
the dataplate, using a suitable fixed wiring
installation in accordance with local and
national wiring regulations. A 3-wire
circular cord of minimum conductor size
2.5mm cross-section area should be
used. A 30A supply fuse should be used,
and a switch with a minimum contact
separation of 3mm in both poles must be
incorporated into the fixed wiring for dryer
disconnection. This disconnection switch
should be accessible to the user after
installation.

As the cable size is quoted in mm (and not AWG) it is highly unlikely to be an American appliance, just an American style appliance.
All you need now is a competent electrician to connect it up as per MI.

 

[sparkwright]

Is it really correct though to fit a 30 or 32 amp fuse when the appliance is a little under 20 amp?

It specifies it in the MI, but would a 20 amp fuse or MCB be ok?

Although the appliance can't be overloaded, why not a 4 mm2 round flex to be in keeping with the 30 amp supply that was asked for?

Would it be better to use a 4 mm2 flex instead of a 2.5 mm2 flex?

 

[Echo the husky]

Is it really correct though to fit a 30 or 32 amp fuse when the appliance is a little under 20 amp?

Yes, because that's what the manufacturer specifies.

It specifies it in the MI, but would a 20 amp fuse or MCB be ok?

I would not want to run a fuse right at it's limit on a heavy continuous load, as the fuse will run rather warm.

Although the appliance can't be overloaded, why not a 4 mm2 round flex to be in keeping with the 30 amp supply that was asked for?Would it be better to use a 4 mm2 flex instead of a 2.5 mm2 flex?

I would and have done several times before when I used to install appliances as a job.

 

[sparkwright]

Thanks Echo.

Looking at the other topic on appliance fusing that's active at the moment, would it be correct to make the round flex a minimum of 4 mm2 to match the fuse?

That's what that discussion tells us.

Although this appliance can't be overloaded, would it be good practice to use 4 mm2 flex?

 

[EFLImpudence]

It depends on the fault current.

 

[endecotp]

would it be good practice to use 4 mm2 flex?

Two points:
- Follow the appliance manufacturer's instructions.
- Do you know what the current-carrying capacity of 2.5mm^2 three core round flex in free air is? It it the same as twin+earth of the same CSA?

 

[JohnW2]

6 mm2 is more readily available to buy, and for the difference in price may prove future-proof should you need to add something.

Is it only me who feels it a bit odd that people are talking about 6mm² cable (or even 4mm² cable, come to that) for a dedicated circuit for a load which is (just) under 20A?

Kind Regards, John

 

[333rocky333]

6 mm2 is more readily available to buy, and for the difference in price may prove future-proof should you need to add something.

Is it only me who feels it a bit odd that people are talking about 6mm² cable (or even 4mm² cable, come to that) for a dedicated circuit for a load which is (just) under 20A?

Kind Regards, John

Are they saying it because the OPS instructions say it must be on a 30 amp supply.

I used to do single sockets in pubs with 32 amp 6mm in case at a later date they may need a second fridge and the higher rating seemed less prone than 16 or 20's to nuisance tripping

 

[ericmark]

You can get a 20A fused isolator

but I would not want one in my house. In a Pub OK but not really in-fitting with my decor. I see a basic problem either 2.5mm² with 20A MCB or 4~6mm² with a 32A MCB both for flex and to isolator/cooker connection unit.

I know we break the rules with a hob and an oven and supply the oven with 2.5mm flex from the double cooker connection unit, but that does not make it right. We don't really know the risk of fault with this unit so personally I would play safe and use a 20A MCB in the consumer unit rather than have an ugly fused isolator next to it.

It is clearly at 20A not a standard domestic dryer and so very likely the manufacturer would expect it to be installed in a commercial premises where a 20A fused Isolator would be in-keeping with what is expected with a commercial premises. Some common sense is required and who ever fits it and signs off the paperwork has to make a judgement. And if that person does not have the skill required to work it out then he should not be doing the job.

 

[JohnW2]

Are they saying it because the OPS instructions say it must be on a 30 amp supply.

Maybe, but I wonder why they are saying that? There are millions of 3kW dryers out there with 13A fuses (and I have one which is also on a dedicated 16A radial), so why does a 4.5kW one need 'a 30A supply'??

Kind Regards, John

 

[JohnD]

Made for a country which lacks our wonderful 13A plugs and 240v (actual) supply.

I've noticed NA homes have lots of radial circuits with their weedy split voltage, and the whole-phase supply to kitchen and laundry is for these man-size appliances.