Generator transfer switch

[Tuco]

With news of planned 3 hour power outages this winter, does anybody have experience of, or plans to safely connect a generator to their house? what is a realistic size needed for a 3 bed? I was thinking a 3.6kva would prob be suitable as long as you don’t use the kettle during a power cut. Is there a simple solution to just keep the basics running (landline, router etc (got to keep the elu 177e operating at all times)). Maybe a battery with an inverter just to power the router, not got the luxury of 4g in the Wild West.
I know its very unsafe but a friend keeps a double ended plug on a cable which he has used in the past (plugged into the cooker socket). But he’s always worried his kids will find it when it’s not in use and start messing around with it even though he always tries to hide it in a safe place when he’s not using it.

blondie!!

 

[Sideways]

If you are going whole house, then you need a large two pole changeover switch rated 60, 80, 100 Amps because it's going in your meter tails and will have to carry the full load of the house when switched to mains not Genny. You can't do this yourself. You'll have to get a sparky to do it for you.

Kraus & Naimer make suitable switches. They are big and will probably set you back a good part of £100 plus the installation.

If I were doing it, I'd have the sparky modify my wiring so that a smaller transfer switch came AFTER my consumer unit. This would then need to feed probably 3 miniature circuit breakers ( the house wiring has to be protected correctly even when fed from the genny). I'd run only 1 lighting circuit, the gas boiler circuit, the freezer and a double socket for the tv/computer + router. You can't be doing without UKW during a powercut
A small genny should be enough for that and you won't be able to mess up by trying to boil a kettle with it.
The second method is unlikely to be cheaper but it's a better solution.

This isn't a DIY job. It's notifiable to building control.

Tell your friend he's stupid and a scumbag for putting his wife and kids lives at risk, and potentially some poor sod doing maintenance on the supply cables. It's worse because he realises it's dangerous and is doing it anyway.

 

[Just4Fun]

I know its very unsafe but a friend keeps a double ended plug on a cable ...

I have read earlier that this is unsafe and have seen this called a "suicide cable". Could someone explain why it is dangerous? (Just out of curiosity; I am not thinking of doing this).

 

[Sideways]

1. Because you can unplug one end and have mains live on a totally exposed bare pin. Plugs and sockets are never made to be used that way. Live feed should always be on a shielded contact to prevent you touching it by accident.
2. There is also no safety feature to prevent mains from the generator being fed back up the supply cable to where someone might be working on a repair, having turned off the real supply and not expecting a supply to come back up the cables from a home, since that would be illegal....
And 3. no safety feature to prevent AC mains (when restored) from backfeeding into the generator and burning it out. The householder might have a way to switch off the incoming supply but might not, and might not remember to use it. Too many mights ...

 

[sawtooth-9]

We are faced with power outages quite often, being in a rural area.
As I see it, there are two options ( aside from sitting in the dark ! )
1 Wire a generator to auto switch in when the mains go out. As sideways says, this is a job for a sparky.
2 We just run a small genny ( 1 - 2 KVa ) and when power drops out, we just plug in the essentials - fridge, freezer, toaster and coffee machine.
Because we run on tank water with a pressure pump, it can be inconvenient, but we do have a 30,000 litre gravity feed water system - so we manually fill the toilet system and wait for the power to come back on to have a shower
We also have a 4.4 KVa genny to run a small electric oven - but our main cooking is done with gas or our wood burner ( in winter )

 

[Stuart Moffat]

I have a henna and it is simple for us to unplug freezers and fridges to the Ginny. It wouldn’t be the same for any connected via switched fused boxes though. I’ve never felt the need to use a Ginny for the oil CH system, but contemplating inserting a 13A socket between the switched fused spur for CH and the CH wiring box so the whole CH system can be run off of either, but no possible interconnection between the two.

 

[Jameshow]

I would run my long extension lead to the hall and then several shorter ones to the living room kitchen etc. Completely separate from the mains.

I would tell my kids no heating devices are to be used in this system.

Are pc / routers TV ok to use Genny power??

Think I might go back to my wind turbine idea!!!

 

[Spectric]

I think you are over reacting to these possible blackouts, I lived through them in the seventies and we only had candles back then, now we have low power LED torches and headlamps so at least you won't be in near darkness. The bigger problems today are that many gas hobs will not function without electricity due to the flameout protection, the same for gas boilers and landlines are also not going to work but then many have some form of mobile.

 

[flh801978]

Landlines should always work
with a hardwired phone
cordless phones need power
you should always have one hardwired phone plugged in

 

[nickds1]

I'm currently in the process of installing a 100A 3ph ATS (Automatic Transfer Switch) and a 3ph generator with autostart.

This is not a job for the faint hearted - I'll do the mechanical installation, but all the electrical work will be done by a fully qualified industrial electrician used to doing data centres etc.

An ATS is a complex bit of kit and is generally supplied pre-built by specialists and fully tested. Typically it consists of two mechanically and electrically interlocked breakers and a modular control unit plus a bunch of sensors. The ATS also provides the generator with a "start" and "stop" signal plus senses when it's up to speed and stable; conversely, should the generator stop unexpectedly, the ATS returns the system to a safe state. The ATS controller is a smart unit (microprocessor controlled) and normally takes its power from the generator start battery (12 or 24V).

 

[Stuart Moffat]

I think you are over reacting to these possible blackouts, I lived through them in the seventies and we only had candles back then, now we have low power LED torches and headlamps so at least you won't be in near darkness. The bigger problems today are that many gas hobs will not function without electricity due to the flameout protection, the same for gas boilers and landlines are also not going to work but then many have some form of mobile.

Roy,
Re candles in the 70’s, I was a teenager at the time, and round our way candles became hard to find. My attitude to health and safety then was not that well developed! I used to make a few bob repairing valve radios and TVs, and ended those that were beyond hope (or beyond my capabilities) I dismantled for spares. I remember using valve ‘cans’ as a useful component in making paraffin lamps! I used a bottles with screw caps with a hole tight for the wick to be pushed through tightly, then a valve can with a similar tight hole at the top to distance the flame a few inches from the bottle. They worked well and all my friends asked for one! No idea what their parents thought!

 

[Spectric]

I'm currently in the process of installing a 100A 3ph ATS (Automatic Transfer Switch) and a 3ph generator with autostart.

When I was involved with these type of backup systems we used to have a large UPS to hold the supply up whilst the generator came on line.

Landlines should always work
with a hardwired phone

unless the local exchange is also having a power outage.

 

[Jameshow]

I'm going down to the hardware store to ask for 4 candles!!!

 

[Tris]

Sort of related question- if there are domestic solar panels feeding into the grid, how do they avoid feedback into the grid in a power outage?

 

[flh801978]

Don’t local telephones systems always have ups’s ?

 

[Spectric]

Don’t local telephones systems always have ups’s ?

Many only on the emergency numbers, but now I think the thinking is most households have at least one mobile phone. Not really thought about the power for the mobile phone mask though!

domestic solar panels feeding into the grid,

There must be protection in the invertors otherwise with a power outage the invertor would see effectively a short circuit, you would be expecting it to feed the grid.

 

[nickds1]

When I was involved with these type of backup systems we used to have a large UPS to hold the supply up whilst the generator came on line.

All key equipment in the various buildings on the property is supported by online UPS systems - these protect both against brownouts (which we get a lot of) and the interval between utility failure and the generator coming online/ATS switching over (typically about a minute or less). The UPS systems have a run-time of nearly an hour which could be considered huge over-kill, however if the generator doesn't start and the outage is long (as we had during Eunice [*] earlier this year), then you get some time to either sort the genset out or gracefully shut the various systems down.

Equipment covered includes all PCs & networking equipment (including access points, routers, switches, inter-building wireless links etc.) plus the base stations of DECT phones etc. Printers are not included, nor are fridges, heat pumps and other sundry non-critical kit that will happily restart after a break.

All access points, cameras & links are PoE (powered over ethernet), so if the PoE switch is on a UPS, all the connected PoE equipment implicitly is too. This arrangement greatly simplifies providing uninterrupted operation during utility issues.

[*] We lost all power for 36 hours.

 

[Myfordman]

Landlines should always work
with a hardwired phone
cordless phones need power
you should always have one hardwired phone plugged in

Not always the case now as telecom operators change over to digital voice. This system always needs to be powered up in the house and the cabinet which can be up to a mile or so away.

 

[Spectric]

supported by online UPS systems

I would not say an hour is that overkill but depending on the loads then you might have a large bank of batteries. Is the UPS 6 or 12 pole?

 

[flying haggis]

Not always the case now as telecom operators change over to digital voice. This system always needs to be powered up in the house and the cabinet which can be up to a mile or so away.

Cabinets usually need power if it is fttc, they can be powered from batteries but that usually means openreach or whoever going to the cabinet and connecting the batteries. mobile phone masts might have battery backups but how long they would last??