Low mains voltage (200V)

[Crossy]

Further update:

I got home a short time ago and after I turned on the WiFi on my phone I got a Line message from my wife saying the PEA would check the power at 4 pm.

I don't know if they have been or not but the power is now at 223V.

Keep checking it, just in case it's a coincidence, but looks promising.

To check an earth really is earth (and not just disconnected), measure from live to the 'earth', you should get 220V.

Also a 15W tungsten lamp will light between live and earth if the earth is 'reasonable' but take care nobody is touching anything metallic in the house just in case (if you have an RCD / RCBO / Safe-T-Cut it should trip when you connect the lamp).

[JamieP]

Also, assuming I was checking it correctly there is no voltage between earth and neutral.

I checked the voltage again when I got home today and it was still up at 217/218V so hopefully all is ok.

I'm measuring mains voltage between live and earth so that's good news but I don't have a tungsten bulb to check further.

EDIT : I re-checked the earth-neutral voltage (this time I remembered to change to a lower range). I measured approx 2V. What might this mean?

[Crossy]

N-E of 2V or so is just fine if you have no MEN link (TT system), nothing to worry about

[JamieP]

Thanks for all the help.

Hopefully things will be fine from now

[Mojomor]

Everything looks okay, but is the fan now okay on the higher voltage??

It seems to me that PEA checked the trafo and found a tap not working properly, so they either replaced, or switched to a spare tap. They're like that. Anyway OP has the correct voltage now so should be okay o a day to day basis.

The photo of the shower unit only shows 2 wires, which worries me. It implies no earth.

Thanks to the OP for coming back. It increases our knowledge greatly.

OP forget about the tungsten lamp ----- this is for pros and only pros.

[JamieP]

The photo I posted of my consumer unit shows and the cable I asked about is going to an aircon unit - but that probably should still be earthed?

[JamieP]

The fan is now better.

[Crossy]

You really should earth the aircon although in reality few seem to bother (our are).

Good to hear the fan has recovered.

[JamieP]

Further update:

I got home a short time ago and after I turned on the WiFi on my phone I got a Line message from my wife saying the PEA would check the power at 4 pm.

I don't know if they have been or not but the power is now at 223V.

And yet another update:

The PEA have just been to the house and they checked everything out and to cut a long story short, they switched us to a different phase. We're now getting 233/234V and even the small fans suddenly feel more powerful.

I can now say for sure that the PEA didn't do anything the first time. It turns out I'd just missed them before.

[Mojomor]

Further update:

I got home a short time ago and after I turned on the WiFi on my phone I got a Line message from my wife saying the PEA would check the power at 4 pm.

I don't know if they have been or not but the power is now at 223V.

And yet another update:

The PEA have just been to the house and they checked everything out and to cut a long story short, they switched us to a different phase. We're now getting 233/234V and even the small fans suddenly feel more powerful.

I can now say for sure that the PEA didn't do anything the first time. It turns out I'd just missed them before.

This is very interesting. Thank you. It suggests a number of things to me as follows: ----

1 ---- If everything was okay, why did the PEA switch you to another phase?. Reason I pose the question, is that sometimes power companies like to keep their ''dirty'' loads on one phase. The dirt washes out back at the trafo.

2 ---- It appears from your report that you are now getting 230V, which is the European standard. Naturally a huge amount of equipment such as fans etc, is built for this standard. Some of us have noticed this gradual change by PEA for some years now

[JamieP]

As it happened when they checked the supply the voltage had dropped back down to 207V.

Even though my previous post indicated that things appeared slightly better (which it was) I still had my own doubts that things were fixed.

I know they've done something know so I will see how things are and post again if need be.

[Crossy]

It's probably as good as it's going to get, unless you have some really sensitive equipment I'd leave alone until it again becomes noticeable.

Our voltage varies throughout the day from 230V in the early morning down to 205V in the evening when all the domestic loads are on (and rather lower when SWMBO is watering her plants (5HP of water pumps).

[IMHO]

It's probably as good as it's going to get, unless you have some really sensitive equipment I'd leave alone until it again becomes noticeable.

Our voltage varies throughout the day from 230V in the early morning down to 205V in the evening when all the domestic loads are on (and rather lower when SWMBO is watering her plants (5HP of water pumps).

5HP?!?!? wow wow. Where do you get the water from to support those kind of flow rates LOL

[Crossy]

It's probably as good as it's going to get, unless you have some really sensitive equipment I'd leave alone until it again becomes noticeable.

Our voltage varies throughout the day from 230V in the early morning down to 205V in the evening when all the domestic loads are on (and rather lower when SWMBO is watering her plants (5HP of water pumps).

5HP?!?!? wow wow. Where do you get the water from to support those kind of flow rates LOL

There's a ruddy great river right next door

A 2HP 2" pump lifts from the river about 4m into a 2,500 Litre buffer tank (not really big enough but it was hanging around doing nothing). Then a 3HP 2¹/₂" pump distributes to the garden watering system. There's also a 1HP 1¹/₂" pump that we run when just using the hose (the pumps are in parallel with non-return valves to ensure the water goes the right way).

Float switches in the tank control the lift pump and stop us running it dry if the lift pump is off (river too low) and the watering pumps have flow switches to switch them off when watering stops.

[lopburi3]

Is it worth asking the neighbours to see what they're getting? Would it prove anything worthwhile?

Sure that would be helpful...at least it would help you confirm whether it's just "your" residence with the low voltage or all the residences around you.

Not really related...

We sometimes have "outages" for a certain time (up to hours).

170 Volt!

All devices with switching power adapters (router, latop) work well.

Some LED bulbs still on. Other lamps (neon) can not be started.

Water pump on low rpm.

Fans on low rpm (dangerous, can overheat).

AND: sister in laws house (15 m away): everything OK.

Different transformer and/or different phase.

Actually that 170v reading is what we normally get when one of the transformer fuse links get blown by lightning strike and lasts until repaired by electric workers (normally done within an hour here in Bangkok). New power saving lights work well - fans run slow - air con and refrigerators need to be turned off or unplugged as compressors can not start. Normally all power is turned off when workers at site and a minute or two later is restored to normal.