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Across the Big Pond Question

2574 Views 14 Replies 4 Participants Last post by  frank
Do the European device manufacture’s make a stand-alone GFCI receptacle or is a GFI breaker used for your 230 volt circuits? What is the specification for the trip?
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HI John.

Ground Fault Current Interupter (hope that is correct) or Residual Current Device as it is known here in the UK is available in many forms.

Non Industrial Standard Types

1 Stand alone unit rated at amps Single and 3 Phase Din Rail
mounting. This type sits at the main incomer end of a distribution board
and protects all the bus bars upsteam. They come as
rated at opperating times of 10/

30/100mS. Also available are units that
have adjustable settings.

2 Receptacles (mounting boxes) are available in all sizes for both flush and
surface fixing.

3 Accessories also are available with a integral RCD. Sockets and switch
outlets. Again many kinds of fittings and finishes (plastic-chrome-brass-
coloured .

4 Also available is a mcb with rcd integral. Fits standard bus bar and
enclosures. Ideal for local rcd protection when you would not wish to
protect an entire distribution board. Computer runs etc.


Single Phase and 3 phase RCD Incomer

RCD rwin socket

Local rcd fused protector outlet

External Weatherproof RCD socket

Hope this helps.

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Excellent post, Frank. Thanks.
Thank you for the information but I need some more help. What I have is a customer that needs to test electrical appliances after they are manufactured to make sure they work properly. The customer sales products to all the European countries including the UK. They are getting customer complaints that the product keeps tripping their RCD's and the customer here does not have way of testing here with RCD's. I made them a test box with all the European receptacles that they told me are used(see picture). Now they want me to come up with something to test with RCD's. I drew up a print of what I assumed would be a transformer to convert US 208 VAC to European 230 VAC(see diagram). Is this correct? Do you think I can use one of our GFI single pole breakers? Would the different frequencies make a difference?

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Hi John.

Well you sure have a good selection of outlets on your test bench front panel.

Your Company's problems are strange. The equipment should not activate a RCD unless the insulation resistance to earth is very low?

Anyway. You need a 2 pole RCD for sure. You could easily mount one on the external panel of the test bench or if you want to be posh then on the inside also. The frequency of operation will have no effect upon the operation of the RCD.

The transformer idea is good one but I would trytwo or three other methods first.

1. Use the US 208 Voltage as the test voltage. European voltage is 230 V and given the plus/minus factors that can occur with supply voltages I would think that all apparatus will work perfectly at 208V

2.The secondary side of the transformer windings should not be earthed. The transformer must also be non isolating .The metal casing of the test bench will be of course ( also bonded to the earth pin outlets )and this should carry to the neutral/earth point upstream of the primary. Set the trip times to 30mA. This is the //ameter for domestic rcd units.

3. You could use the tansformer as you have drawn but the earth must be at the centre tap of the windings. The RCD then could be fitted in the secondary side.

I would go for No 1 myself if the equipment works at 208V

Let me know the results of your experiment. If you need to source a UK double pole RCD I can help there also.


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I am going to go with option #3. There are 10 of the receptacle boxes and 10 5KVA transformers that I made for this customer a year ago. I can easily change the transformer taps. They were wired for 120/240 single phase and I will just take out the 120 Volt. Do you have a link where I can get the 2 pole RCD?


I am coming to the USA next week. Arriving Boston Thursday afternoon.I can bring one and post to you direct or you can use the link below.

Go into electrical then Consumer Units and the page with mcb's and incomers pops up.

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Now THATS service!! :thumbup:

I want to thank you very much for your help. I did find a US supplier of European electrical equipment. I am working to upsale the customer on installing an European electrical system for their plant. I may have some more questions for you in the future.


By the way do you need an apprentice? I would love to come over to the UK and learn some new skills. :thumbsup:

Carry On!
Pleased to hear all is well. I looked at the link you gave. This is a great site for those awkward bits and bobs you don't normally come across.

If you have other questions don't forget I leave home Thursday. Back May 27th.

Wrong date.

Nope . Not back 27th. I am back the 13th. Only in New England 10 days.

What do you use to test a a RCD? I tried to test a RCD with my IDEAL SureTest and the second that I plug it in it trips the RCD. After I read the instructions for it I found out that it will not test a 230 volt GFCI (RCD). I have seen some RCD testers made by Fluke and Megger but I cannot find a US source for one, just UK suppliers. Do I really need to test or calibrate the RCD? The Test button on the RCD does work.

Hi John

Nice to be back home and to hear from you. Scratching my head I could give you all kinds of waffle as an answer. But I suppose first I should say that any of the manufacturers RCD testers you have named should suffice. My thoughts however are that the current/voltage ratio's of your Sure Test tester does not come up to spec for a 230 V RCD.
Your fault would indicate a tester fault but if you are sure it is not issuing a fault current prior to applying the test proceadure then I can only guess at something else.
Tomorrow I will contact the Manufacturers of UK RCD units and ask how low can a test voltage be and what might cause the problems you describe.

Hi John.

The problem is with the Sure Tester, or so the folks that know such things tell me. The Ideal Sure Tester is not configured for dedicated time lapse rcd testing . Utiising the test button proves the integrity of the resudual current integral circuitry but it does not prove the full electromechanical characteristics of the RCD. You should be able to obtain a 230 volt multirange RCD tester in the USA. They are expensive however. Even new here in the UK.Say $500/600 I am not sure how you test RCD units in the US.Since I believe you do not use the bus bar mounted types (only socket types) then a RCD tester for outlets will be of no use. Unless you can get a 230 volt model and fit flying crocodile leads to the outlet plug and then test the RCD at the input poles. But going by what the Megger Co told me today you would need to ensure that the GFI tester was designed to switch up to 230 volts and test at 30mA and 100mA at Half Times and one Time and Five Times trip current to meet UK spec.

If all fails I could maybe get you a discounted one or even a calibrated second hand one from this end.

Be sure to let me know.

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Hi John

Just before I fly off. And just minutes away. A manufacturer of RCD units phoned me and confirmed that you can test at 50 volts to 300 volts any RCD/GFI. It is the instrument that is important. I checked wholesale prices here for RCD testers. One that tests 10 to 1000 mA in 10 stages from 50 to 1000 volts opperation 0-180 degrees etc would cost £195. Plus Tax.

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