Battery swap for cyberpower UPS

[Bill_Bright]

Too bad they didn't give you some sort of estimated time for the repair to happen. I suspect your issue is not very high on their priority list, and certainly, depending on weather and other unforeseen circumstances, could easily slip down the list. But I think if me, I would reply and ask for a "rough guess" as to when they might get to it. As it stands right now, it could still be 6 months or longer.

One thing nice is now you have a name to contact and bug.

 

[chrcoluk]

Of course yeah, power cuts will be priority.

I can understand it would be hard to give me a date as they will likely have to apply to the council for permission to do works. But if I dont hear anything for a while, I might prod him, to see if there is updates.

 

[Bill_Bright]

Of course yeah, power cuts will be priority.

Not just cuts, but the number of customers affected as well as the priority of the customer. For example, hospitals, fire stations, banks and the like have a higher priority than residential units.

 

[chrcoluk]

As you warned me I havent heard anything, and there has been no local works since when we were talking about the switching.

However I notice today it has moved down to 243v, if I remember I will send a new email to the contact asking if there is an update on the plans.

 

[Bill_Bright]

Still insufficiently caffeinated this morning so not willing to go back through and read 5 pages of posts. But let me say this. It is normal for the mains voltage to vary throughout the day. I have a small meter I keep full time in my kitchen for Ss & Gs and throughout the day I see it go from 118VAC to 120VAC, occasionally down to 117VAC and up to 123VAC. Here in the US, anything between 114 - 126VAC, at a frequency of 60Hz, is considered normal service.

In the UK, according to this,

...the voltage in the UK is 230 volts and the frequency is 50 Hz. Note, however, that British energy regulator Ofgem permits a tolerance of -6% to +10%, which gives an allowable voltage range of 216 V to 253 V in the UK within official limits.

This means your 243VAC is "normal".

 

[Harlow]

This means your 243VAC is "normal".

A few years back, the mains voltage at my mother's house frequently went up above the official UK limit of 253V, especially at night. When we complained to the electricity board, they sent us a data logger box and collected it a week later. Despite the results showing occasional excursions over 253V, they were not deemed long enough to warrant remedial attention, because the total duration per 24 hours was less than 5%.

Further investigation revealed that in the past, someone further up the hill had complained their kettle took too long to boil, especially when the voltage was low, so the supplier raised the voltage tap on the 11kV to 240V AC transformer in the field nearby. Daily voltage sags were caused by milking machines in the dairy shed at a local farm.

One day I heard a loud bang and saw a bright flash nearby when an overhead mains line (supported by wooden poles) dropped to the ground. When the repair crew arrived they replaced the 630A mains fuse on the 11kV transformer and a second overhead line immediately fell down in a shower of sparks. The culprit turned out to be a tree branch which had come down in a storm and shorted out the overhead line and neutral wires in a wood.

When they cut down the tree branch and replaced all the damaged and melted lines plus another 630A fuse, normality was restored. They also followed my suggestion and reduced the tap on the 11kV transformer, now that the milking parlour has closed. The voltage is currently 247V AC, but I know my meter reads higher than the calibrated meter used by the repair crew. It's better than the 261V I used to see on it before the tap was changed.

I've just checked the mains supply with a multimeter which reads 242V. The other permanently connected meter now shows 246V and PowerChute UPS software says 240V. Take your pick. I doubt if any of them are "correct". As I've mentioned in other posts, I've measured 55V to 330V AC in various hotel bedrooms abroad.

 

[Bill_Bright]

As a technician who made a career out of repairing and maintaining electronics, I've "invested" in a few good multimeters over the years, from Simpson and Fluke and now my current digital multimeter from Mastech. I know it to be quite accurate (rated at ±0.8% + 3 digits), plus I compared it to a voltage "standard" in a lab used to repair and calibrate precision measuring devices.

Surprisingly, that little plug-in voltmeter I mentioned before and again above (one of these) is quite accurate too, as verified by my Mastech. But it rounds off the voltage to the nearest whole number so I would not use it for precision measuring. Same with the LCD readout on my UPS. Whole numbers only, but still pretty accurate.

If you don't trust your multimeter to be accurate, I would buy a new one.

 

[chrcoluk]

Confirmation they have fixed it.

A long wait for what they actually did.

The recent investigations we carried out following your concerns about your electricity supply have confirmed that our system was in need of improvement. I am pleased to inform you that we have now carried out a modification of our system.



The modification carried out was:



• The Voltage setting has been reduced at the transformer that supplies this part of our network.

Still insufficiently caffeinated this morning so not willing to go back through and read 5 pages of posts. But let me say this. It is normal for the mains voltage to vary throughout the day. I have a small meter I keep full time in my kitchen for Ss & Gs and throughout the day I see it go from 118VAC to 120VAC, occasionally down to 117VAC and up to 123VAC. Here in the US, anything between 114 - 126VAC, at a frequency of 60Hz, is considered normal service.

In the UK, according to this,

This means your 243VAC is "normal".

243 is the new reduced amount, I guess you forgot the history of the thread, it was previously going over 253v.

 

[Bill_Bright]

I didn't forget the history. I knew you were dealing with mains voltages that were too high. As I noted, I just didn't want to (okay, I was being lazy) go back through 5 pages of posts to get the specifics. I was pointing out that it is normal for there to be some variances throughout the day and still be considered "normal".

I am really glad that (1) they fixed the problem and (2) that they actually notified you that they found the problem, admitted it was their problem, and how they corrected it. That was, IMO, some quality customer service.

Thanks too, for the update.