Electrician installed a whole installation RCD

Nov 09, 2015 57 Replies

Again ignorance of what must be done all over the world so that equipment will work in regions with better safety standards. For example, everything on a circuit (ie some 20 devices operate on one 5 milliamps RCD) without tripping it. Because that is found in North American venues and therefore in major facilities throughout the world. No problem since electrical equipment must leak typically less than 100 microamps. Even construction sites must have many equipment on one 5 milliamp GFCI without tripping. Any equipment that leaks 3.5 ma would cause consternation on job sites. Same 'less than 5 millampss' applies to secure facilities all over the world because that equipment is also used in and must also operate on North American's much safer GFCI standards.

Return to the point; to what is relevant. A tripping 100 mA RCD means a serious human safety issue. Move on to what the OP must do to have human safety.

You are arguing nonsense using standards that are considered insufficient in many venues and for human safety. Relevant numbers for human safety were for faults of less than one second. 30 milliamp protection is too high for what are normally one circuit powering 20 appliances. Everything you have posted demonstrates only local knowledge; insufficient for international design requirements. And is irrelevant to the OP's problem.

Apparently you want to argue safety standards that are inferior to what is found elsewhere; rather than address the purpose of this thread. A useful engineer would address reasons for RCD tripping either due to appliance failure, interior wiring faults, or a combination of both. And yes, we have seen where an RCD would only trip due to a combination of both - which can make solutions challenging. Nuisance tripping happens in venues with safe wiring when appliances leak an excessive 3.5 mA. But that is not the OP's problem. OP has a much worse fault that exceeds what is required for human safety. Move on to what is relevant here.

You have extension leads with 20 things plugged in to them from one socket!

One thing most of the world didn't follow the USA on was, very wisely, their dire and rather primitive electricity installations.

Which standard mandates that for IT equipment?

That might explain why electrocution is the second leading cause of death on American construction sites. 15% of traumatic deaths in the US construction industry are due to electrocution compared with 1.5% in the UK.

The population of the USA is about 6 times that of the UK. In the year 2009 about 100 Americans died due to electrocution in the home from consumer products alone.

In the UK in the same year the number of people who died from electrocution in the home from all causes was 5.

I hope you don't feel offended if we stay with our "inferior" system.

We all agree that a 100mA RCD does not provide adequate personal protection but we are not talking about that but a 30mA one.

You mean the USA having an electrocution death rate at least 3 times higher than the UK is because of their "superior standards"?

That was NICIEC advice.

Supply issue - both were PME.

How about reading what the OP wrote.

He doesn't have a tripping 100mA RCD, he has 30 mA RCD that is tripping

Ahem......

Really, how do you know that?

Not directly, of course: you daisy-chain the extension leads. Have you never seen a meeting where 20+ people have laptops plugged in at the same time.

Again, your knowledge is only of local wiring standards using inferior protection.

20 appliances on many receptacles can and must be powered by one RCD that will trip on 5 milliamps. You should have known that long before denying and posting. Many appliances on one 5 milliamp RCD is routine in venues where human safety is better.

Informed engineers routinely design equipment to leak less than 100 microamps. A

3.5 milliamp leakage is unacceptable in venues where better safety exists. Properly designed equipment must work without tripping any RCD anywhere in the world - even on construction sites. 20 items, each leaking 3.5 milliamps, is unsafe, unacceptable, and routinely avoided by simple and proven designs.

You again subvert this thread with what is totally irrelevant. OP has a fault so serious as to even trip a 100 milliamp RCD. Can you concentrate on the topic rather than posting feeling and myths generated by ignorance? Why do you routinely and repeatedly ignore the OP's problem? Why do you subvert this thread by promoting unacceptable designs and obsolete standards? Can you assist the OP?

Fair do's. Is that published advice because you said "you would put a lack of RCD on stage sockets as a code 1" rather than saying that you had?

I was intrigued - thanks. What was the result, a rapid change to TT?

You sound unemployable.

Nonsense. No "must" about it.

This thread is subverted by you when the OP was asking about a 100mA RCD. Do keep up rather than showing your ignorance, or even a lack of comprehension skills.

And that's just in the home.

Prisons in Alabama, Florida, South Carolina, Virginia, Kentucky, Tennessee, Arkansas and Oklahoma are also rather high risk.

Owain

No need to daisy-chain; up to 20 sockets here:

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Owain

No, we are well aware that wiring in the US is generally crap. Crap electrical accessories, use of Ali cables, wire nuts etc... shudder!

Please try and get a clue. Go look at the specification of a typical RFI suppressor and explain how you are going to design your equipment to have a leakage of less than zero!

Is readin not your strong point? The OP said (and I quote verbatim):

"an electrician installed a whole installation 30mA RCD recently"

That is what is tripping, not a 100mA RCD.

Because we can read.

Why?

Better than what? The US standards are dire. Very few are International standards because no one is willing to downgrade to meet them.

If they are so good why do so many more people in the USA (as a proportion of population) die of electrocution than in the UK?

I presume the "venues" you are wittering on about are Wally's burger bar?

Name some (and when you do, remember how many more people are electrocuted at work and at home in the USA than in the UK).

There are no documented cases of anyone being killed or injured by a circuit protected by a 30mA RCD.

No it doesn't, as you have been told several times by others. He hasn't fitted a 100mA RCD.

I haven't seen those before, but I've seen plenty of situations where they would have been useful!

Olson stuff is awesome. It's often available on ebay, and I have 4 large strips in my study, totalling 76 sockets ...

Your RCDs must be tripping all the time.... ;-)

Thankfully much equipment is double insulated associated with leakage currents only Mr Westom can dream about.

I doubt the sockets will be fully populated!

Either from the Connections mag or similar. Backed up by my manager.

F*ck no. Roads dug up at 11pm the same night on one of them:-) Took them 3 day to fix that one as it also affected quite a few houses.

Never. There aren't 76 things plugged in. About 20 or so.

(And I miscounted, there are 5 strips. Same number of sockets, though.)

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