Red 100A light on the electricity meter and high pitch noise

[Rainmanne]

Two nights ago we noticed a high pitch noise coming from outside. It was quite loud that our daughter, whose room s in the loft couldn't sleep and we had to close the window in our bedroom too. I was trying to find the source of the sound but couldn't. It seems like being above our house which is quite bizarre.

I also noticed that we have a solid red light on the electricity meter on the indicator, which says 100A. I just wonder if the noise and the light are in any way connected. I have never noticed the light before. I have uploaded the photo (without red light as it's gone in the morning).

Last night we had the same noise and the light. The noise started just after midnight and was gone by morning. It was still on at 5am.

I'm going to contact our electricity company to check if anything could be wrong but I just wonder if I can do something to get rid of the noise if it's back tonight.

 

[JohnD]

look at the (actual) meter readings. How many kWh per day and per night do you use

- usually

- since this noise?

How is your hot water heated? if you have a cylinder, please provide some photos of it.
Has the tapwater been surprisingly hot?

Please photograph your consumer unit ("fusebox") with the lid open so we can see the circuit labels and the MCB numbers.

Do you have an "Economy 7" or similar night-time off-peak electricity tariff?

 

[AndyPRK]

The 100A light means you are using LOADS of electricity. and it will be costing £££
If you don't know how it's being used, there is also a small fire risk concern. or certainly a fault.

If it returns you could try switch off your fuse box switches individually, to see if one of them stops the noise/light, finally switching off the main red switch. (it could rule things out if nothing else)

 

[Rainmanne]

look at the (actual) meter readings. How many kWh per day and per night do you use

- usually

- since this noise?

How is your hot water heated? if you have a cylinder, please provide some photos of it.
Has the tapwater been surprisingly hot?

Please photograph your consumer unit ("fusebox") with the lid open so we can see the circuit labels and the MCB numbers.

Do you have an "Economy 7" or similar night-time off-peak electricity tariff?

I actually took the meter reading on Saturday:

Night: Was 04433, now 04437 - 4 usage
Day: Was 19228 now 19238 - 10 usage

We have a cylinder boiler. All plumbing and electricity was completely redone 2 years ago when we refurbished the house.

Tap water is fine.

I've attached the fusebox photo.

Yes, we have day/night tariffs.

I've looked at the history. For example in Nov-Dec last year our daily usage was 4 at night and 14.5 during the day. So I guess it's OK.

The 100A light means you are using LOADS of electricity. and it will be costing £££
If you don't know how it's being used, there is also a small fire risk concern. or certainly a fault.

If it returns you could try switch off your fuse box switches individually, to see if one of them stops the noise/light, finally switching off the main red switch. (it could rule things out if nothing else)

I tried to switch everything when it happened first on Saturday night and it had no effect on the noise. Although I read somewhere that you need to have it switched off for 20-30 minutes. Not sure if it's true but going to try if the noise starts tonight.

 

[JohnD]

If it happens again, start by turning off the water heater.

What colour is your hot water cylinder?

 

[Rainmanne]

If it happens again, start by turning off the water heater.

What colour is your hot water cylinder?

I guess it beige.
This night was OK and I have checked the red light on the meter this morning and it was on. So probably, it's normal. WIll see if the sound appears again this night.

 

[JohnW2]

The 100A light means you are using LOADS of electricity. and it will be costing £££

How sure are you about that?

In my (limited) experience, I have never seen an indicator light on a meter labelled "100A", and find it hard to imagine what its purpose/meaning might be. When, as is common, there are two LEDs, it is usually the case that (as with my meter), one flashes N times (N usually 1,000) per kWh and the other flashes N times per kvarh. Looking around online, I can't find anything quite like the OP's meter.

Interestingly, for reasons I've never understood (and which are not apparent from the meter's technical manual), the kvarh LED on my meter quite commonly shows red constantly (i.e. not flashing) for appreciable periods of time, inevitably during the night when little electricity is being used. However, whatever may be the cause of that, it is not related to very high electricity consumption, nor to any error in metering.

Kind Regards, John

 

[JohnW2]

Interestingly, for reasons I've never understood (and which are not apparent from the meter's technical manual), the kvarh LED on my meter quite commonly shows red constantly (i.e. not flashing) for appreciable periods of time, inevitably during the night when little electricity is being used. However, whatever may be the cause of that, it is not related to very high electricity consumption, nor to any error in metering.

This is rather extraordinary, and presumably reflects the fact that I haven't really paid much attention this before ...

.... I need to retract the "... inevitably during the night ..." in that quote above. It's about 3pm, and I've just noticed that the kvarh LED on my meter has been continuously illuminated (red) for at least the past 20-30 minutes (and is still 'on'). My present total consumption (from my own monitoring) is 547 W, and the kWh LED is flashing occasionally, appropriate to that consumption.

Edit: the kvarh light has just gone off, about 40 mins after I first noticed that it was on (but I don't know how long it had then been on). My current consumption is 573 W.

Kind Regards, John

 

[AndyPRK]

I think so. A cleaver way of showing the supply is at full capacity.

Yes the pulse light stays on if little current is being drawn. I wondered if that was the light that was on this morning? If one just glanced at it?

 

[JohnW2]

I think so. A cleaver way of showing the supply is at full capacity.

I'm still far from convinced, not the least because I can't really see the point of such an indication. Furthermore, I looked online at dozens of current meters last night, and not a single one of them appeared to have such an indicator.

Yes the pulse light stays on if little current is being drawn.

That seems rather odd - but it might explain my kvarh lighting staying on continuously for 40+ mins this afternoon.

Hopefully, someone might eventually pop up who understands the meters in question.

Kind Regards, John

 

[Robin0577]

Whilst I haven't found anything that explicitly states the purpose of the 100A LED, this technical specification https://www.landisgyr.com/webfoo/wp-content/uploads/product-files/5246_Technical_Specification11.pdf does say the meter has an internal 100A contactor, presumably to control off peak heating. I wonder if the LED simply indicates that the 100A contactor is engaged. That would seem a slightly odd way to label things, but it makes slightly more sense than it being a full load indicator.

 

[DetlefSchmitz]

I have no idea - this is totally a guess. But suppose the indicator changes state every time certain amount of kWH is used. If you are not using a lot then it will remain in the on or off state for lengthy periods. (refers to John's puzzle)

 

[jg321]

this technical specification <link caused moderation> does say the meter has an internal 100A contactor

I've just seen the exact same thing in the tech specs, and came here to post this too.

Suppose it kind of makes sense - "100A contactor is energised" is presumably what it means.

I'd personally be heading to the meter around the time I'd expect it to switch over (which in my experience varies by anything up to 30 mins!), and listening for the click to see if the light comes on at the same time.

 

[333rocky333]

Whilst I haven't found anything that explicitly states the purpose of the 100A LED, this technical specification https://www.landisgyr.com/webfoo/wp-content/uploads/product-files/5246_Technical_Specification11.pdf does say the meter has an internal 100A contactor, presumably to control off peak heating. I wonder if the LED simply indicates that the 100A contactor is engaged. That would seem a slightly odd way to label things, but it makes slightly more sense than it being a full load indicator.

I think you may find its the other way round.
If its a credit meter they can turn the supply off remotely when not paid or change of tenency, the light is normally on permanent except when they turn supply off.
The Landis gyr 5246c has the same Led

You do get MCCB s with a Load led that illuminates when near Max prior to tripping, also can send a remote signal, but as John says no point on a meter

 

[JohnW2]

Whilst I haven't found anything that explicitly states the purpose of the 100A LED, this technical specification https://www.landisgyr.com/webfoo/wp-content/uploads/product-files/5246_Technical_Specification11.pdf does say the meter has an internal 100A contactor, presumably to control off peak heating. I wonder if the LED simply indicates that the 100A contactor is engaged. That would seem a slightly odd way to label things, but it makes slightly more sense than it being a full load indicator.

That sounds credible - it which case one would asume that the LED would be lit continuously for all the night-rate E7 hours, every night.

As I've indicated, I really find it very hard to believe that Andy's suggestion is correct.

Kind Regards, John