Lights flicker- voltage drops intermittently

[stubuzz]

You may have read that my washing machine was playing up, but i think i have found the problem. I checked that connections are all tight in the consumer unit and had a check around all of the sockets but found no issues. Now i have been watching my voltmeter and when the lights flicker the voltage is dropping from 222v to 184v. This is happening intermittently several times a night.

So now what is the fix? Do i need to call out the PEA? I am in the town center and the transformer is on the street outside the house.

[wayned]

You can call the PEA until you are blue in the face but that won't help!  Your best option is ito install an AVR but that isn't cheap

 I live in the "boonies" and have lived with it for 22 years.  When the voltage drops, I turn off my water pump and don't use any of my appliances other than the fridge.  I have a UPS for the computer but no AVR and make sure that I don't buy any appliance with an inverter power supply as they are very susceptible to power anomalies and repair parts are very expensive.

[Crossy]

How long are your brown-outs lasting?

 

184V is -17% so outside the 10% tolerance, but as noted above the usual PEA response is "you have electric, no problem".

 

The occasional flick down to 184V isn't likely to cause any real issues unless it stays down there for significant periods, does it only happen at night?

 

[stubuzz]

1 hour ago, Crossy said:

The occasional flick down to 184V isn't likely to cause any real issues unless it stays down there for significant periods, does it only happen at night?

I am at work in the day, but the problems seem to happen mostly between 6-9pm. The brown outs last for about 1 second each time.

I will speak to the neighbours to see if they are having problems,

[tjo o tjim]

What kind of lights?  If fluorescent, might be time to switch to LED, and trying to buy some with “universal” voltage of 90-250VAC. 

 

Use a UPS for electronics, just a good measure more than anything. 

 

Everything else... either don’t use larger loads in the evening, or get an AVR. 

 

 

[Wirejerker]

You checked your consumer unit connections but did you go any further. The connections on the PEA meter out on the post, are there any splices in your consumer mains. Any neighbours tapped into your supply.


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[NanLaew]

8 hours ago, Crossy said:

How long are your brown-outs lasting?

 

184V is -17% so outside the 10% tolerance, but as noted above the usual PEA response is "you have electric, no problem".

 

The occasional flick down to 184V isn't likely to cause any real issues unless it stays down there for significant periods, does it only happen at night?

 

The voltage drops to around 185 volts every night at our house between around 18:30 and 20:30. PEA come and check every few months, always after lunch and always report 'no problem.'

 

Most appliances manage, albeit less efficiently but I have had to dispose of UPS protection on my computers since my last 3 UPS's start beeping and cut in as soon as its around 198 volts and the cycles between low and normal eventually exceeds the units ability to recharge the battery. That's on UPS's costing between 3800 and 5000 baht. I probably need a more sophisticated one where I can adjust the low-voltage range plus it needs a larger battery but that's possibly an expensive UPS. So in the meantime, I keep IT stuff on surge protectors.

[Crossy]

24 minutes ago, NanLaew said:

The voltage drops to around 185 volts every night at our house between around 18:30 and 20:30. PEA come and check every few months, always after lunch and always report 'no problem.'

 

Yup, that's the usual story.

 

You can get small AVRs suitable for your computer if you want to go back to using your UPS (AVR before the UPS of course).

 

About 5k Baht for a 3kVA one (smaller / cheaper are available, I just don't have the prices to hand).

 

[stubuzz]

Update: The PEA came out and had a poke around. They re-did the connections on the post and where the main cable joins the house wiring. They suggested that we should change the wire from post to the main breaker. Then replace the old breaker with a safety cut/RCBO. (I don't think it will fix the problem, but the stuff is a bit old and needs doing)

He said he could do it on his day off and quoted around 2500bt. This is for 6 meters of 4mm cable and a new consumer unit/safety cut/RCBO.

[Crossy]

6 minutes ago, stubuzz said:

This is for 6 meters of 4mm cable and a new consumer unit/safety cut/RCBO.

 

For your incoming cable??

 

What size meter do you have? (5-15, 15-45, 30-100 it will be written on the meter plate)

 

[soalbundy]

you need a monk, you have an angry ghost. Have I really been here that long?

[stubuzz]

1 hour ago, Crossy said:

What size meter do you have? (5-15, 15-45, 30-100 it will be written on the meter plate)

Its a 5-15. I guess the 4mm is overkill. Most of the house uses 2.5 mm cable so it would need a 30 amp main breaker?

[stubuzz]

1 hour ago, soalbundy said:

you need a monk, you have an angry ghost. Have I really been here that long?

After the washing machine stopped its crazy lights and beeping, i went back to my computer to find that my gmail accounts were missing from the win10 mail app. I did think that something was messing with me!

[Crossy]

On a 5-15 you shouldn't go over a 20A incoming breaker.

 

You are probably overloading the poor thing, 15A at 220V is 3.3kW total!

 

Anyway, if your load when the washer is working is just the washer and a few lights and the TV (no aircon) you're probably good to go.

 

EDIT There are not many of us on less than a 15-45 with a 50A incomer.

 

 

[sometimewoodworker]

2 hours ago, stubuzz said:

He said he could do it on his day off and quoted around 2500bt. This is for 6 meters of 4mm cable and a new consumer unit/safety cut/RCBO.

If that is including the parts, it's good value.

[stubuzz]

On 8/24/2019 at 7:33 PM, sometimewoodworker said:

On 8/24/2019 at 4:45 PM, stubuzz said:

He said he could do it on his day off and quoted around 2500bt. This is for 6 meters of 4mm cable and a new consumer unit/safety cut/RCBO.

If that is including the parts, it's good value.

The guy came back today and had another look. This time he wants to change the main wire from the meter to the house (around 25m). The main cable into the fuse box and change the old fuse box for a large safe t cut. All in around 7,000bt. I showed him alternative consumer units with rcbo protection, but he said PEA only recommend Safe-T-cut brand.

He then said that the neighbors wire from their meter needs to be changed also. Unfortunately, this was changed 6 months ago by another PEA employee. I don't trust this guy.

Here is how the house connects to the main line.

FYI- after they red did the main connections, the lights don't flicker.

[sometimewoodworker]

1 hour ago, stubuzz said:

The guy came back today and had another look. This time he wants to change the main wire from the meter to the house (around 25m). The main cable into the fuse box and change the old fuse box for a large safe t cut. All in around 7,000bt. I showed him alternative consumer units with rcbo protection, but he said PEA only recommend Safe-T-cut brand.

He then said that the neighbors wire from their meter needs to be changed also. Unfortunately, this was changed 6 months ago by another PEA employee. I don't trust this guy.

Here is how the house connects to the main line.

FYI- after they red did the main connections, the lights don't flicker.

He is correct about the rewire, the wrong cable has been used and it should go directly to the main CU not be joined like that, also the twisted joins aren't even protected bu much tape.

 

if the correct cable is used then the cost is in the correct range for a quality job.

 

Quite possibly the last time it was done someone wanted a cheap job and got exactly that. ????