Any device to smooth voltage dips on lighting/stop flicker?

[cjard]

i live fairly rurally and occasionally suffer a problem where the lighting flickers quite a lot in the evening. I'm not certain but suspect it may be due to fluctuations in the supply voltage or by devices in the house turning on and off; perhaps one of the neighbours on the same phase has a massive TIG welder.. perhaps the hob, fridge and heat pump are conspiring to give me epilepsy

I'm curious to know if there exists any device that could be connected into the lighting radial that will smooth out the power delivery, perhaps something like a UPS does for computers, but fast enough that fluctuations in power supply to lighting don't cause visible flickering?

 

[OwainDIYer]

an online UPS would do it but lights etc shouldn't be flickering even in a rural area. Supply voltage fluctuations don't usually have much effect on modern fluorescent or LED lights.

There is a possibility that you have a loose connection at your consumer unit, meter or service intake and this should be checked as it could cause a fire if it overheats.

 

[JohnD]

do your table or standard lamps, plugged into wall sockets flicker at the same time?

What sort of bulbs are you using?

Photos of your consumer unit ("fusebox") and the cables around it and the meter might be informative.

 

[ericmark]

HF ballasts for fluorescents common rated 185 ~ 250 volt, these should not dip with voltage dips, LED lighting depends on the lamp, those designed to dim will vary with voltage, those not designed to dim may have switch mode drivers built it which would mean there can be a huge voltage variation. Using extra low voltage LED lighting the power supplies/drivers are often rated 100 ~ 240 volt see this example the LED lamps designed to fit a GX53 lamp holder I note rated 100 - 240 volt I have never used one, not a clue how good or bad, just noting the voltage range which means they must include a switch mode driver built into them. Most standard LED bulbs with BA22d or E27 caps use a rather cheap method to restrict the current and would flicker with voltage variations. In the main LED lamps with around 100 lumen per watt will have a switch mode driver and will not flicker with voltage variations, those with around 75 lumen per watt will dim and also flicker. There seems to be a drive for dimmable lamps, and the EEC has said any lamp not dimmable must say clearly not dimmable rather than the other way around, so most tungsten replacement type lamps will dim, to get lamps which don't dim and are more efficient in the main you need to change your lamp fittings. There are converters

but never tried using them.

The idea of a UPS may not work to stop flicker, most UPS actually switch from direct supply to back up, they don't actually convert to DC and back to AC and run through the battery.

 

[bernardgreen]

most UPS actually switch from direct supply to back up

A true UPS will prevent lights flickering.

Most items sold as UPS ( Uninterrupted Power Supplies ) are, as Eric mentioned, in reality SPS ( Standby Power Supplies ). There is a brief interruption as they switch from mains to invertor.

The difference in operation between a UPS and a SPS is not critical for most applications where the device supplied can tolerate missing a couple of cycles of the mains. The critical difference is that with a SPS the invertor may not start when it is needed at mains failure. It is not unknown for an inveror to have failed while the manis was present and the failure is only discovered when the mains fails and the device(s) being powered cease to function. If the invertor in a UPS fails then it will switch devices supplied onto the direct mains and raise an alarm to have have the UPS repaired / replaced.

 

[ericmark]

Thank you bernardgreen the problem where a UPS or generator feeds many items when a supply fails is the earthing system, where an UPS supplies a single item it is like with a shaver socket not a problem that we have no earth, just bonding, however for it to supply the lighting radial it raises the question as to earthing, I am unsure with out studying as to if it would technically require an earth rod? However personally I would say the danger removed by not having lights fail must be greater than danger generated by not having an earth? The only reason to raise it is because if you get an electrician to do the work they could raise it.

Personally I would be complaining to the DNO first and only if they can't cure it worry about other methods, even a small UPS to run just LED lighting will likely cost £200 so first is to make sure it is not a lose connection or a supply fault which can be cured by DNO with no cost to you.

 

[bernardgreen]

Earthing has never been raised as a problem with UPS (or SPS ) In simple terms treat the UPS as if the Live and Neutral were directly connected from input to output.

From memory so may be inaccurate ( or outdated )

On TT supplied equipment rooms ( hill top sites ) the CPC ( Earth ) wire just runs past the UPS unbroken.

On non TT sites the I recall that the Output Neutral was connected to Input Neutral at all times. Only Live being switched.

 

[JohnD]

Personally I would be complaining to the DNO first

we haven't yet had information to determine if the fault is on the circuit, in the house, or on the supply.

 

[SimonH2]

Earthing has never been raised as a problem with UPS (or SPS ) In simple terms treat the UPS as if the Live and Neutral were directly connected from input to output.

It's been mentioned here several times.
The problem is that it varies considerably between different types of UPS - and probably even between different models from the same manufacturer. IF the UPS maintains neutral connection between input and output under all conditions then there might not be a problem, but I think there's speculation that many don't, and some may even have some "weird" arrangement where "neutral" running on battery is actively driven to be not the same as "neutral" from the supply. The latter is common with gennys where the windings may be connected such that the output is 55-E-165 when set for 220V output.
Thus there may be situations where a L-E fault on the connected equipment isn't able to trip any protective device. Instead, it may simply tie L to E, and leave N at 240V instead.
So any non-trivial installation needs careful consideration, and that needs detailed knowledge of the design of the specific UPS.

I have to admit, having been installing small (mostly ≤3kVA) UPSs for many years, this isn't something that I'd been considering before reading about it here.

 

[cjard]

do your table or standard lamps, plugged into wall sockets flicker at the same time?

I don't know, as I have no standard lamps. I'll get one and see.

What sort of bulbs are you using?

Megaman dim to warm dimmable LED 240v gu10, driven by a fibaro dimmer2 leading edge dimmer. How it does its dimming, not sure. The radial is wired in 1.5 mm2, 6a BG RCBO, CU is brand new too, as are the meters, service head etc. CU to board is 3 core 25mm (into a switch fuse), board earthing strategy is TNCS. No loose connections afaics.

There are other lighting radials in the house that I think also have some flicker, led and non, I should perhaps do a proper survey of which are affected and see if it helps direct the troubleshooting.

 

[JohnD]

if you have some non-dimming lamps on a plain switch, there's a faint chance that might show something.