Can a safety switch be tripped by an event external to the house?

Forgot to add, one reason I'm curious about this is because I eventually plan to install a residential generator here - a natural gas powered backup gen (permanently wired) that kicks in when mains fails. In this instance I don't think it would have provided power continuity since the safety switch had tripped, and I doubt the backup generator would be wired to bypass this...

I haven't seen it a problem here, the only time our internal breaker has tripped is when something internal has done it.

My UPS trips here by far more often than it did, and now that I'm seeing a fault with it, the server comes down every time there's a brief outage.

Should get to fixing that some day...

--
Linux Registered User # 302622

Possible. I've seen enough electronic device suddenly rattle/shake/roll from something and spurious signals on the powerline seems a common likely.

It is an answer that you are never going to know unless you hae a full time wave logger on the power supply to log wafeform.

Or, it could just have been a cockie having a shit in a warm place {:-0.

Err, generators do not provide power continuity. Their role is to take over the power provision from an approriate level of UPS. You'll need to make sure thatyour UPS can now provide any extra needed time for the generator to come up to speed and sync properly and that the UPS can hand over(?) to the generator.

Unless it is a big bickies situation, you are probably best just going for automated shutdown on the ups, then restart on the generator. There is nothing like the smell of cooked batteies on Monday morning to know that you are going to have techs in again this week to work out what went wrong this time and to repair the damage, yet again.

By "power continuity" I meant that my equipment would not die as soon as mains power disappeared - there's a UPS on all of the important stuff that was going for about 10-15 mins before I shut everything down manually. This is not a large or critical installation but it is used for 24/7 internet business purposes so "continuity" is reasonably important. Just like a RAID array allows fairly normal operation to continue if a hard drive fails, rather than absolute downtime until it is replaced.

BTW, there's little point having a backup gen if the house wiring is isolated by a popped safety switch. ;)

Err, didn't you put your office onto a separate circuit? Makes it easier to swap it over to the genie, aka get a changeover switch installed on that circuit only.

Bad power can't cause an earth current to flow on its own. One of your devices had to have leaked the current, and even if the power is bad a device shouldn't do this unless you have somehow gotten very excessive voltage, like over 400V.

I have seen dust/insects/spiders in PC's do this, light that fail can do it. Once I had a PC near a window and someone watering the garden accidently sprayed water though it and into the PSU shorting mains to earth. Condenstation will do this also. Any thing with a capacitor to earth can do it when the caps leak/fail/open and then it can appear as if nothing is wrong, as most caps to earth are just to filter noise.

One way i often see is when the 'chassis' (usually just exposed screws) of a

2 pin DC plug pack device touch the chassis of a 3 pin device. The 2pin devices can have a cap between a DC terminal and chassis, which then goes to the next chassis and to earth, causing an earth leakage current to flow as the cap changes its charge.

[...]

This is my main concern, that it *was* a coincidence, and there's possibly an issue which will rear its head again. I have 5 UPSs, 7 PCs, assorted networking equipment and an air conditioner in the office. Of course there's also all of the other sundry electrical equipment in our house.

It was 4:15am so it's unlikely that the switch was tripped by a one- off event caused by a human (or feline - they were asleep on the bed with me)

Of note is that the power dipped twice again during the day, so perhaps the substation wasn't quite so isolated.

Possible. After renovations, our safety switch would trip every few days, always at exactly 7:58 AM. I searched for the problem, and when I was convinced it wasn't in our house, argued with the power company about it. Initially they denied it and said I should replace the safety switch because it was too sensitive, but after I pointed out that it can't possibly be *time* sensitive, they agreed to replace it for me.

The contractors they sent said that they'd replaced hundreds, and it was caused by the power factor correction capacitor banks being switched in at that time, in preparation for industry firing up for the day. The new safety switch has never false triggered since.

It doesn't help you work out what actually happened at 4:15am, but it indicates that something on the power line could have tripped it, and that getting a different one might make it less likely to happen again.

Clifford Heath.

Do you have a brand and model worked out? Or just an idea?

Given that multi-hour outages are becoming more regular here and we have the gas mains in the street, it is interesting if I can find the business income to justify it.

I didn't have a specific model in mind, but I was looking at Kohler Power Systems as the brand.

Heard from a USA acquaintance that a 35kW setup cost about $USD30k fully installed. I wouldn't be looking to power the entire house so that level would be overkill. (Would a typical residence even consume anywhere near that much concurrently??)

If it is an emergency power plant, then you have to look at exactly what you really need to keep running. If it is servers/internet presence for a business, then that is one thing, and should be reasonably economic to do.

OTOH, if you've trained the family such that they think the air con and ice maker should keep running no matter what, then you'll probably need it.

The problem I can see is that is if you have anything significant, you are basically sitting on a residential gas feed and it is going to experience peakish demand about the same time you see want a big generator running. Yep, most of our neighbours strike up the BBQ when the electric power goes out. Newer homes will have those BBQs on the gas feed.

I had looked at the bottom end stuff from Advanced Power a while ago, but that was a significant whack to convert a petrol to LPG at the time. Frankly, we could get away with a basic genie outside the window approach even now, but I'd change my mind if it started to happen every quarter.

If (when X) I was going to be spending $30K, then I'd look at grid attached solar(rebates, reducing current ongoing expenses) with onsite batteries option. If the grid goes off, then I'd have the batteries to feed the UPSs for the computers(*), inverters, etc.

Then I would add the gas generator, although, it might be better to think more along the lines of "battery charger" in that case.

(*) I am currently looking at mini-box.com dongles that allow you to run computers directly off batteries. They claim 90% & recharging lead acid is about 90%, so 80%+ efficency as a full time feed now(no UPSs). Really need to get out the DMM and see just what the real efficency of my current computer power supplies are.