Medical devices and US 220V electrics

The self-cleaning gas ovens I've seen use electric elements for cleaning and modern codes around here require a separate circuit for it. A microwave adds another 10 amps, so kitchen renovations often require adding a couple of circuits. Just changing the oven could require one new circuit and the OP's product is probably a lot more expensive than a range.

The point is that adding new circuits to existing homes is usually a

Replacing an electric range with another electric range is no big deal. New ones, even self-cleaning, don't take any more power than those from fifty years ago.

No. Just two armoured cables going to the neighbours through the ceiling.

No it is certainly *not*. Don't be an ass.

As I said...

AIUI, the 80% capacity rule is for dedicated circuits. Any such spec for utility circuits would be meaningless. Likewise, it also doesn't apply to devices plugged into the utility circuits.

At least where I used to live, 15A circuits weren't allowed except for wired lighting.

BTW, NEMA 5-15R is allowed on a 20A circuit. IOW, because you have a NEMA 5-15R receptacle, doesn't mean that it's a 15A circuit, just that the outlet is only rated for 15A. It may be a simple matter of replacing the receptacle on the existing circuit. Though anything else on the circuit may cause a problem.

That is a Really Bad Idea, medical or not. And the reason it'll be a regulatory nightmare is because it _should_ be one.

North American wiring usually puts multiple sockets on one circuit, so chances are very high that both plugs would go into the same circuit, and just blow a breaker.

So, yea, you need to knock the power draw down by a _lot_ or accept the fact that your gizmo will need special circuits.

There's marketing and there's sales. I don't know about your product, but many expensive devices are sold by "lending" them to the customer with the understanding if they like it you will get a PO. A dedicated power line might make this harder to do regardless of who pays for the installation. The electrical work would not be expensive in any real sense compared to the cost of most medical equipment. But just the procedural issues involved make such a demo much harder to make happen.

The good news in the US is that a 30 amp 208/230/240/2x0 volt (whatever the nominal voltage is) is a pretty common standard outlet if you are working at that voltage. Many clothes dryers use them. The connector is a NEMA 14-30. For higher current devices (like charging cars) the NEMA 14-50 connector will supply 50 amps which is way overkill for your device.

The building wiring up to the outlet will need to support the full rated current of the connector. The current capability of your cable can be sized to match a fuse in your equipment. So you don't need to use 10 gauge wires in your device cable. They are big, heavy things. Does your machine get pulled into position? If so, the bigger the cabling the more of a PITA it is.

No, it's not. It's about design. A dedicated circuit has to be designed for its load and they want the 80% derating. The current in a multi-drop utility branch can't be anticipated so such derating is meaningless.

This always PO'ed me. I want a real electric snowblower, and lawnmower. I lust for a British 30A 220V ring socket....

But all we have is wimpy circuits providing flea power.

My only hope is more garages are getting electric car chargers; lotsakilowatts!

Oh, good grief. Just add a 240V circuit.

Nonsense.

There is nothing magic about EV chargers. Just do it.

In Europe, the most common sockets are:

Here (UK) they're mostly 240v 30A with some 240v 20A.

NT

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The "ring mains" wiring used means that a given circuit can deliver 30 amps in total.

.... Phil

Yes, if you mean continuous ratings. IRL our ring circuits routinely deliver far above the rated 32A. And a bit naughtily, 30A welders are often run on a 13A plug without problem, as they're not continuous 30A loads.

NT

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( apologies to Jack Nicholson)

The 16amp breakers commonly used here will often trip at 16 amps, given a few minutes and warm weather.

..... Phil

Greg

re internally fused as well.

They allow it for long enough to not cause nuisance trips when rings delive r 45 or 50A, as is routine in UK households. Naturally they don't run that high for more than 10 or 15 minutes.

The magnetic breaker component acts on large overcurrents only. The thermal bit is the one to act on long low level overcurrents. It has to be rated t o pass 32A continuously at max rated environment temp, so no surprise it pa sses well over 32A for a fair time.

they are. Bolts even more so.

a few minutes and warm weather.

Ours are specced to never trip at rated current.

NT

If you have 208 V, there must be a full 120/208 V three phase feed nearby.

To the OP, when 3 phase is available, why not use a full 3 phase (6 pulse) rectifier. It just requires two extra diodes compared to a full wave single phase rectifier. When split phase 240 V is available, only

In Europe with 230 V 16 A would give similar DC voltages.

A 3x16 A 230/400 V feed would give considerably higher DC voltages.

Thus, the device power supply should be built as an ordinary three phase 6 pulse rectifier with a storage capacitor (for single phase). A

I've been looking into the electric car thing and Tesla specs a 240V 50 amp socket which gives 25 MPH charging. I think that is the same size circuit as my backup electric for the heat pump.

Chevy has the Bolt, they are not nearly as proactive about the charging issue. I'm not sure what they recommend for charging, but unlike Tesla they don't get involved at all in your installation.