Single phase makes it very easy. Your easiest choice  now reduces to 32A blue plug, or 16A blue plug.

Watch total capacitance to earth if you have lots of kit with built in mains filters - it is likely that the users will want to supply it via a 30mA RCD (==  GFI) and the out of balance current that flows with 230V between L and E will be proportionally larger than 110V designers are used to.

Don't go above 10mA of total earth leakage or the wheels can start to come off in terms of false alarm tripping - as well as making a lost earth first fault to an immediate  danger condition.

Mike

(In general we like metric nuts - spares are available in every hardware shop. Things that use funny threads that have to be ordered off the internet and flown in and arrive a week late are a pain in the bottom .. The other happy alternative is to find a few spare screws and nuts in a bag in the back of the box).

mapj1 said:

Much of what we do is R and D or temporary ,and the legal advice has always been to always UKCA or CE mark if there is money or benefit in kind changing hand, even business to business when the recipients do not want or need the marking for their own purposes.

Yes, that's always the recommended approach. However, exceptions are permitted, for example see Regulation 3(2) of the EMC Regulations 2016 (as amended): www.legislation.gov.uk/.../3

Will D said:

I wanted to avoid looking for "loopholes" as we don't want to risk the equipment being rejected.

Yes, this is definitely the best approach, and, like Mike, with the exception of individual experimental circuits in a suitable lab or workshop, something I would always follow myself.

Hi Mike,

Very helpful again, thanks. Are plugs typically provided on cabinets like this? I was expecting a fixed wiring installation directly into the cabinet would be acceptable, though I will certainly confirm with the host first.

Good tips on the capacitance, earth leakage and earthing nuts thanks. I also prefer metric, though I believe this is unusual in the USA.

Will

You do not have to connect via plug and socket, but racks that may need to be isolated to be worked on or pulled out to be got behind very commonly are. Data centres seem to be full of connectors like that. It also makes it easy for the local sparks to decide where his work stops - make socket on wall live, run usual BS7671  polarity and earth impedance checks and  then pack tools away and go for an early lunch - that way the power is ready in advance when the rack arrives.

It also avoids having to wait and then argue the toss about who is terminating the interlinking cable and if the rack needs testing as part of the fixed wiring - which of course  is where we came in.

At least over here those connectors are cheap as chips compared to labour, and do make testing and isolation to prove dead particularly easy.

But do check with your customer - their local chaps will have their local preferred method.

Mike.

Ah well, if the PDU has a C20/C19 inlet - then the simplest thing might be just to plug a UK lead into that - e.g. https://uk.rs-online.com/web/p/power-cords/3119315 (or more likely with a blue 16A BS EN 60309 plug).

   - Andy.

Thanks again Mike, invaluable advice. Certainly, avoiding any question as to whether the cabinet is part of the fixed wiring is a good enough reason alone.

Yes, since we _can_ use plugs we should. We'll confirm how the local electrical supply will be provided. Cheers

When you do the confirming in your shoes I'd be forcing it a bit. Along the lines of (but delete what you do not want)

"

The rack will consume up to Xxx  watts at 230VAC single phase.

So we can provide a suitable lead, can you confirm that  the supply will be one of the following, and which is your preferred.

13A socket to BS1363

(do not offer this if there is any doubt it may not be enough, say more than 2000 watts or if you do not want it to share a breaker and RCD (GFI) with everything else of no great importance in the building)

16A blue single phase socket to BS EN 60309

32A single phase socket BS EN 60309

Flex to bare ends for your non standard termination (not preferred)

Unless otherwise requested the supplied lead will be nominally ~1.8m (6 feet) long from the bottom left rear of the rack.

Or where ever it exits from the rack, so they know where to put the socket.

"

Avoids doubt, and allows them to get power to the right place at their end in advance. Anything more than the 13A socket will probably have them running in a new line, in 2,5mm cable or larger for the 16A or 4mm cable or larger for the 32A, and that is likely to be more reliable, as no-one will then unplug it  to use the vacuum cleaner....

Mike

Good shout Mike, thank you, we'll get a suitable cable with a plug which meets the hosts needs.