Mains switching

[Drew Stephenson]

I power my studio off a twin wall socket with both switches being turned off and on daily. I try and have everything that has an SMPS switched off before flicking the socket switches but I have read (I think from Folderal) that these switches aren't designed for this kind of frequent use and I have had a couple of situations where something hasn't switched properly and it's tripped the circuit breaker.

So is there a more appropriate device for powering up mains sockets? I know you can get remote switchable ones but I had some of those that were, in the absence of a better term, crap; and I don't need remote switching as I designed the sockets to be reachable.
So really just something that plugs into the mains sockets and is designed for regular switching.
Is this a thing?

[Wonks]

The remote control mains switches often talked about here should be designed for on-load switching (otherwise there wouldn't be any point in them if you had to turn everything on and off manually before you used them!).

[Drew Stephenson]

That's the functionality I'm looking for but without (necessarily) the remote bit.
But I guess as long as they have a manual switch too that'd be fine, it was the remote part of it that stopped working on the ones I used to have.
So any recommended brands or models would be super useful if anyone has a good experience?
Thank you!

[Hugh Robjohns]

I continue to be impressed by Energenie remote switches.

https://energenie4u.co.uk/catalogue/product/ENER002-3

Alternatively, if you use Alexa-type systems Energenie do replacement wall sockets which communicate via WiFi and can be controlled via Alexa commands. They call it miHome, and there are options to control all sorts of things.

I like the idea of walking in the studio and saying, "Studio Power On!"

Regarding SMPS devices... these can pull huge transient currents at switch-on. 50 or 60 amps is not unusual. So if you're powering up several at once the surge current could easily cause a breaker to trip out.

So, if possible, try to arrange a staggered power-up for such devices, rather than all at once.

[James Perrett]

I'm using an immersion heater switch for most of the studio which, I presume, is designed to switch a reasonably substantial load. The monitors are on a separate switch.

[Sam Spoons]

I do similar with a double pole 'cooker' switch which is wired to switch line and neutral on both legs of the ring (unorthodox wiring with a pair of 2.5mm2 cables running from the breaker in the consumer unit to the switch up to which point they are in parallel*, from there the ring goes round the trunking in the studio feeding 12 or 13 double sockets).

I turn the computer and mixer off before powering down but the monitor amp and a couple of other items are powered on by the master switch. I don't get and pops when switching on the Mac Pro and X32C.

* I did the wiring up to the master switch over 20 years ago and I don't see any practical reason why it might be considered unsafe but I don't suppose it would pass the current regs?

[ajay_m]

The main concern with on load switching is arc flash at the point when the switch opens. This is exacerbated with inductive loads, such as switching power supplies, but to be honest because these work at relatively high frequencies they do not normally present a significant store of energy as the actual transformers are much smaller than traditional 50/60Hz units. It is old-fashioned transformers which can be an issue depending on the point of the mains cycle at which power is removed. However normally this isn't a concern until you start getting up to several hundred VA rated units.

Unless you have some very high current devices I wouldn't normally expect either manual switching or switching through a remote switch device to be an issue (normally these use a single pole relay and probably ought not be used with more than 5-6A total current on the circuit, just to be safe, though they are typically rated 10A or thereabouts). Splitting the circuit across multiple remote switches and ganging them in the remote app is the simple solution to that problem. For example my studio monitors each have a separate remote wifi switch, but the two switches are ganged so that the monitors can be turned on and off with a single button press.

Inrush current at turn on, conversely, does have a risk with relay-driven switches of potentially welding the relay contacts closed. This will normally result in a failure to cycle power off when commanded. Additionally if the inrush current is high and the breaker is sensitive, it may trip.

If a circuit is equipped with an RCD device and that trips, then this indicates a potential safety issue in that a current discrepancy has occurred between line and neutral. This would normally require a fairly urgent safety test on all equipment.

[ef37a]

Well, you could go nuts?
https://www.screwfix.com/p/wylex-100a-d ... sure/321fr

Heh! Just had that fitted along with my smart meter.

But yes, I would go with Hugh's idea of wireless switches. I have them all over the shop and have never had a problem in 5 years or so. If you don't need the remote function they have an operate button, most usually on the front.

One additional benefit of the switches is that they fail off if there is a power outage when you are not around but then so do RCD sockets and consumer units and most of us have those now?

Dave.

[Folderol]

Something like this?

https://www.nibroadcast.com/bryant-10am ... -unit.html

Enables you to do a properly managed start-up such as sources first, speakers last

[The Elf]

My entire studio runs from 'smart' power sockets, all under the control of Home Assistant, and has done for many years.

IME the Philips Hue sockets seize up after a while (sometimes within weeks), so I'm demising those as they demise themselves. The cheaper Energizer sockets have been 100% reliable.

[Drew Stephenson]

I continue to be impressed by Energenie remote switches.

https://energenie4u.co.uk/catalogue/product/ENER002-3

These look like they will do the job. Thank you all for the suggestions.

[ajay_m]

I have used these RF devices in the past and had remote control failures from time to time. In my opinion the WiFi controlled switches are better. Firstly the control apps on your phone usually offer more sophisticated control options and secondly you don't have a dedicated remote to lose or find batteries for. There are a ton of models available now, too.

[Jimmy B]

I don't need remote switching as I designed the sockets to be reachable.
So really just something that plugs into the mains sockets and is designed for regular switching.
Is this a thing?

To pick up on AJ's earlier post, it doesn't sound as if the socket outlet is failing to switch the current. (If it was, a replacement is very inexpensive). Rather, it sounds as if inrush current from multiple devices downstream is tripping the breaker upstream.
This could be due to a faulty breaker (not very likely) or excessive inrush current (likely).
Many devices, particularly older ones, have been designed without inrush current limiting. This is OK when only one device is in use, but a whole room full of such devices may trip a modern breaker.
It is possible, but expensive, to limit the inrush current from all of the devices using one external inrush current limiter:
https://www.canford.co.uk/Products/42-7 ... MITER-230V
This device is rated at 10 amps continuous, so unless the devices are using over 2KW of power (which might make the room rather warm), one may suffice for everything.
The cheaper (but less convenient) solution that is being proposed is to switch on the devices in groups, so that the inrush currents are spread out. This should work provided that there aren't too many devices.
I do wonder whether it might be easier and cheaper to use a simple multi way switched socket strip, rather than the remote control devices that are being discussed?
https://www.screwfix.com/p/masterplug-1 ... d-2m/7902g

[Wonks]

If the consumer unit breaker that keeps tripping is quite old, it may be that a straight replacement may work without tripping on startup. But you will probably be better off with a different trip characteristic breaker could be used - e.g. a type D if you currently have a Type B, as these type Ds are specifically designed to allow high inrush currents.

[ef37a]

I have used these RF devices in the past and had remote control failures from time to time. In my opinion the WiFi controlled switches are better. Firstly the control apps on your phone usually offer more sophisticated control options and secondly you don't have a dedicated remote to lose or find batteries for. There are a ton of models available now, too.

You do need to replace the battery from time to time! Ok, bit rude but as I said, the switches have a button on them so no real need for the remote in this context.

Obliged Mr W for the information about "type D" breakers. I don't have a problem but always good to be kept informed.

Dave.

[Wonks]

Though a type C MCB may suffice as it will allow more inrush than a type B but not as much as a type D. The residual current protection side stays the same, but it will take slightly longer for a type D to trip due to a short than a type B or C, and a type C will take longer than a Type B.

Type B will trip at 3-5 times the rated current, type C at 5-10 times the rated current and type D at 10-20 times the rated current. They aren't particularly accurate devices, so some will trip at the lower end of the tripping current range, some at the higher end of the tripping range. Which is why swapping out one MCB for another of the same type can solve occasional tripping issues (or possibly make it worse).

If the MCB is 'cold' i.e. nothing was switched on before on the circuit, then it will take a bit more current for it to trip than if it's already 'warm' and running at a reasonable load when you then get a big inrush current added on top.

So for occasional inrush tripping problems, I'd suggest a type C MCB, as a type D could be overkill for the application. They don't cost much, so you can always move up to a Type D if necessary.

[The Elf]

I like the idea of walking in the studio and saying, "Studio Power On!"

Actually that's literally what I do as I walk towards my studio (actually "Power up the studio"), speaking into my phone/iPad, Alexa/Echo box, or even my TV remote - the light comes on and the sequenced power up begins.

By the time I've pressed the momentary power buttons for the few bits of gear everything is ready to go.

Adding automation like this (and much more) to my home has been a revelation.

[Drew Stephenson]

Just a bit of context for my particular use case (other people's experiences may vary):
Currently all the studio stuff runs off two* pairs of mains sockets that were designed to be easily accessible.
One pair covers lights, internet connection, and bits and bobs that don't get switched on every time. The other pair covers computer, monitors, sub, screens, control surfaces, interface and everything else that's basically on the main desk via two 6-way extenders (these are not easily accessible). Of these, only a couple of them are 'always on' - the only one with any significant power draw is the sub.
When powering up and down I always leave a little gap between flicking the mains switches so there's as much of a staggered power-up as I can manage without crawling around on the floor behind the desk.
So I'll keep that basic sequencing in place, but without the chance of arcing across the mains sockets.
Or at least that's the plan.

The consumer unit was installed at the time of the build in late 2019.

* There is a third mains pair but that runs my other 'day-job' desk and other music stuff that doesn't get switched on as frequently.