Power Cuts

[Ed P]

We have recently suffered a couple of power cuts each of which has lasted over four hours and hit a wide area. (I think a 415 KVA transformer complex was taken out by a major fault.) This experience showed that my system was nowhere near as resilent as I thought.

LESSONS LEARNED

a) A widespread power cut does not knock out the Broadband network as I guess BT has suffifcient standby battery/generators to cover. So the broadband network stays up. However this does not necessarily apply to mobile 3G/4G/5G if the booster transmitters lose power as they often have only minimal power backup. All our mobile networks were down within 30 minutes.

b) However, although BT stays up, your domestic system only stays up as long as the UPS attached to the router, switch, wifi modem stays up. Ours lasted only 2 hours.

c) Be careful of plugging your main broadband master cable into the UPS, I did (to get surge protection). When the UPS goes down you can lose your landline in this situation.

d) Fancy wifi phones are only as good as the power to the base station, these went dead almost immediately, and the base station also stopped working. (Even if it had stayed up plugging the main broadband connection into the UPS would have brought it down with the UPS.)

Main lessons for me were that I had not expected all comms to be wiped out, and not only do I need to think where to plug in the broadband master cable, I also need to think about the capacity of my comms UPS. I also need to consider whether to buy a simple POTS phone as a standby, but I’m not sure what will happen when landlines go Internet only.

[JayCeeDee]

Ed P wrote:

but I’m not sure what will happen when landlines go Internet only.

VOIP can forward calls to mobiles in the event of internet being down, but then, as you have highlighted above, how long will mobiles last??

We are setting a lot of faith in VOIP, but landlines were always impervious to power cuts as the power ( 50v ) came from the exchange, which had both battery and generator backup systems. I would have wanted both, but that option is being taken from us by BT’s unilateral decision. There is a glimmer of hope, as per this BBC article :-

What if there is a power cut?
Old landline phones receive power via the line itself, which is separate to the household mains electricity supply, and often remain functional even during a power cut.

Internet-based phones, however, rely on home routers or similar devices.

Ofcom requires phone operators to come up with back-up solutions, though, to ensure people can call emergency services.

Virgin, for example, intends to offer battery-powered back-up lines to customers with accessibility needs or who cannot rely on a mobile phone during a power cut.

The battery provides 24 hours of standby and one hour of talk time.

And an engineer will install a small box in the customer’s home so they can connect.

That is something of a half measure though and needs further thought/planning. I thought that I might pre-empt this by taking a business broadband connection with Sky that offered VOIP. That was scuppered when they told me that I would need to change my home telephone number. I declined!!

Edit – WTF??!! – I had to copy the article into WordPad and then copy back into the topic to remove all the text formatting etc in order to get it back into readable English!!

[JayCeeDee]

One other thought, Ed, iirc you have solar panels. If you get a home battery fed from the panels – or cheap off peak electric – this will act as a better backup than UPS’s.

The Tesla Powerwall and Gateway2 is one ( very expensive ) option. Other batteries and equipment can do the same, providing almost instantaneous changeover ( ~20 – 40ms ) from grid to battery when a power cut occurs. It has been said that PC’s won’t notice this or crash within this gap.

You can also select which circuits ( ring mains or lighting ) are prioritised when the power goes down. This could be to keep router, TV, media box, combi boiler, microwave and fridges and freezers powered up.

[Author]

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