Rural Suffolk. About 300 metres underground on the LV cable which run back to a poletop 11 kV transformer. We are on the far end of this LV line. The 3-phase HV distribution then runs overhead cross country for tens of miles.

We are prone to two main supply disturbances:
1. outages on the HV side. UPS fitted on all network and IT equipment. It’s not unknown for outages to last from 15 minutes up to 4+ hours. The property is 3-phase connected and we have a 60 kVA backup set that kicks in through an auto changeover mains fail detect board.
2. Longer term voltage swells, especially in the summer/warmer months.

The last big strike (high summer) was particularly nasty. It wasn’t a direct hit but indirect and made worse because we have fairly long radial connections to barns and outbuildings from the supply which is a PME (TNC-S) arrangement. Long copper ‘spur’ connection are a mare with strikes because of earth equipotentials - which can result in nasty surges. We suffered a lot of equipment damage and outright destruction.

Some important lessons were learned -
1. Fit permanent type 1+2+3 lightning/surge arrestors before the main board, and also at any sub-boards, especially where these are being supplied externally.
2. The text books are right when they say it’s not a good idea to run copper data cabling outdoors, between buildings. Always use fibre between buildings if possible.
3. Big impulse spikes are impressive in their destruction.
4. Get professional advice on additional earthing arrangements.
5. Have (some critical) spares ready.
6. Sometimes unfortunately your luck just runs out!

In reply to a post by Pheasant:

we have fairly long radial connections to barns and outbuildings from the supply which is a PME (TNC-S) arrangement.

I am surprised you're PME as I thought with all 11kv to 240v transformers in rural locations (e.g. up the top of poles) meant you had to supply your own earth via a TT connection.

In reply to a post by Pheasant:

In reply to a post by j0hn83:

2 posts from 2 different users, 12 hours apart.

1 post advising don't buy a [censored] UPS from Amazon, likes an APC, as they are rubbish.
Next post advising don't buy a [censored] surge protector, buy a good 1 like APC.

Personally I like APC kit and think it's perfectly fine in a domestic environment.

Personally I no longer really rate APC, especially the consumer stuff. Once upon a time, moons ago, they were quite good (perhaps before Schneider bought them). I suppose what coloured my experience were batteries that invariably died after only 3 or so years, sometimes sooner. If you can’t get at least 5 to 8 years from a UPS battery then it’s a pretty poor show.

The lifespan of the batteries will be partially related to the type of UPS it is - good quality UPS devices are online and run off the batteries at all times - this does degrade them faster but provides a vastly superior electrical feed to the protected equipment.

If you're getting 8 years from a battery, the odds are that it won't be providing the runtime it was designed to, the battery won't be in good condition and when you actually need it, it will let you down.

Thank you for your reply. Now I understand your interest in protection equipment.

I live in a rural area where the local electricity supply is all underground. The transformer that serves the area is next to my property. It is connected by an underground cable about 200m long to the overhead distribution system. Trees falling down sometimes hit these lines and cause power cuts.

I think two of my dial up modems failed due to local lightning strikes. I have not had the same problem with my ADSL broadband equipment, and I stopped using the phone line about 5 years ago when I got an undergound fibre connection.

There are many big trees locally so I hope they will attact lightning when they are wet. I have not had any electrical damaged by the electricity supply in the past 35 years. I just hope the same will be true in the future. I have wondered about fitting a surge protection device but have not done anything so far.

In reply to a post by therioman:

In reply to a post by Pheasant:

In reply to a post by j0hn83:

2 posts from 2 different users, 12 hours apart.

1 post advising don't buy a [censored] UPS from Amazon, likes an APC, as they are rubbish.
Next post advising don't buy a [censored] surge protector, buy a good 1 like APC.

Personally I like APC kit and think it's perfectly fine in a domestic environment.

Personally I no longer really rate APC, especially the consumer stuff. Once upon a time, moons ago, they were quite good (perhaps before Schneider bought them). I suppose what coloured my experience were batteries that invariably died after only 3 or so years, sometimes sooner. If you can’t get at least 5 to 8 years from a UPS battery then it’s a pretty poor show.

The lifespan of the batteries will be partially related to the type of UPS it is - good quality UPS devices are online and run off the batteries at all times - this does degrade them faster but provides a vastly superior electrical feed to the protected equipment.

If you're getting 8 years from a battery, the odds are that it won't be providing the runtime it was designed to, the battery won't be in good condition and when you actually need it, it will let you down.

Not really. I've got deep cycle off-grid batteries (the same type fitted to UPS units) that are going on 10 years and are still perfect on conductance and load drop tests.

Do you load test your UPS batts regularly?

On line or offline style of UPS makes no odds - if the UPS is fully online - then the rectifier / inverter should be standing the full load of the UPS *and* providing sufficient current for float or recharge of the batteries. Deep discharging batteries that are designed for the purpose categorically does not shorten their design lifespan.

Battery life span is mostly shortened by inadequate charging and high temperatures. But the reality is that most consumer UPS are fitted with cheapo batteries and fairly unsophisticated / rudimentary charging systems, so that batteries simply don't last.

A quality battery(ies) will see out 10 years, no problem

In reply to a post by dect:

In reply to a post by Pheasant:

we have fairly long radial connections to barns and outbuildings from the supply which is a PME (TNC-S) arrangement.

I am surprised you're PME as I thought with all 11kv to 240v transformers in rural locations (e.g. up the top of poles) meant you had to supply your own earth via a TT connection.

Yeah we are, always have been and when we were upgraded in 2013 onto 3-phase it was again PME.

However I’m led to believe DNOs are slowly coming full circle on TT. The regs now mandate stuff like external vehicle charging is now separately earthed as TT - effectively an earthing island.

In reply to a post by Pheasant:

Yeah we are, always have been and when we were upgraded in 2013 onto 3-phase it was again PME.

Fair enough, because the earth rod for PME has to be done at the foot of the pole containing the transformer and the network supplier cannot guarantee it (e.g. someone comes along and removes it) is the reason why I thought everyone with a setup like this had to be TT.

I have learnt something new

In reply to a post by Pheasant:

[A quality battery(ies) will see out 10 years, no problem
[/quote]

Hum, the batteries in the UPS at work which costs more than at least some houses and from which you could certainly run 99.99% of houses; well the batteries don't last that long. Not even remotely. The idea that they are skimping on the batteries is laughable in the extreme.

That said new APC consumer grade UPS's are junk compared to what they used to be.

So how often do they replace them. What bread if battery are they using? What UPS incidentally?

Not really. I've got deep cycle off-grid batteries (the same type fitted to UPS units) that are going on 10 years and are still perfect on conductance and load drop tests.

Every vendor recommends 3-5 years at most. My experience is that the APC 'first party' batteries last no longer - or less than - third party ones of the same specification, but they do tend to degrade. Have I seen batteries still working in UPS devices for longer than that - yes (we often inherit a customer where the battery has not been changed). Is it normal? No.

(Side note... the batteries in my car tend to last around 5 years, after which they become noticeably worse. It's noticeable if you are using them in the winter or have left them standing for a while. It's almost like batteries degrade over time...)

Which leads me to...

Do you load test your UPS batts regularly?

Yes, every 2 weeks for our own stuff. Not as often for customer stuff. We also have active tracking of estimated runtime for the UPS devices we operate, and I can tell you, that despite your assertion they last a decade, that 3-4 years in, the runtime, for the same load will reduce. All batteries degrade in time.

Battery life span is mostly shortened by inadequate charging and high temperatures. But the reality is that most consumer UPS are fitted with cheapo batteries and fairly unsophisticated / rudimentary charging systems, so that batteries simply don't last.

If you're referring to some generic brand of UPS maybe, they're usually poor for many reasons, the battery is usually the least of the concerns with those (you can guarantee they'll be useless when you need them, and in the meanwhile they're usually so electrically noisy they're causing other issues).

But we're not talking about those, and my real world, multi-decade experience across brands and environments does not tally with yours.