Multimeter

[zlodnick]

When checking the house voltage with my digital multimeter, what does it mean when the numbers keep changing?

 

It won't stay on one number for more than 1 second.   ( 205-212-217-205-204-197-198-202  etc. etc.)

[JBChiangRai]

Voltage varies with load your side of the transformer.

[zlodnick]

Neighbors stay on one number.  Is it a concern?

[JBChiangRai]

What do you have running? It probably varies with whatever you are running.

 

An AVR (Automatic Voltage Regulator) will keep you closed to 220v

[Crossy]

Task-A = fit new batteries in your meter.

 

If you have an older analog type multimeter you can use that to see if the voltage really is hopping around (this type of meter still has its uses).

 

[zlodnick]

Just tried a new digital multimeter, same thing.

 

Should I be concerned?

[Crossy]

31 minutes ago, zlodnick said:

Neighbors stay on one number.  Is it a concern?

 

Are you saying that you checked a neighbour's place and they don't jump?

 

If so, you may have a bad connection somewhere. Any "fizzing" noises or "interesting" smells? check all your breakers for discolouring of the plastic.

 

Check the voltage at your incoming breaker, and at the meter.

 

Whilst you are there check that the connections are tight, use a well-insulated screwdriver, wear rubber gloves (new washing-up gloves will do) just to ensure you don't get a tingle.

 

[zlodnick]

Neighbors stay on one number.  Is it a concern?

 

Yes, the neighbors don't jump.

 

I'm too afraid to test the breaker or meter.  PEA supposed to be here this week. I'll ask them to do it.

 

Thanks Crossy.

[Peterphuket]

Not so difficult, before I had solar cells I also had that problem, not far from me is a car repair shop and has a welding machine, this causes the tension to vary greatly.

To avoid this I bought a automatic voltage regulator, this keeps the voltage constant.

With the solar cells it is not needed anymore, and is now for sale.

[bluejets]

Word of caution....all meters have a catagory number.

The number is associated with the recommended allowable use.

There are diagrams out on the web which show the ratings and use.

 

If you use say a cat 1 meter on mains measurement at a switchboard for example, best get ready for a potential blow up.

Basically it is a measure of the meters ability including the test probes, to withstand the peak voltage levels that occur.

 

Edited April 29 by bluejets

[Muhendis]

55 minutes ago, bluejets said:

Word of caution....all meters have a catagory number.

The number is associated with the recommended allowable use.

There are diagrams out on the web which show the ratings and use.

 

If you use say a cat 1 meter on mains measurement at a switchboard for example, best get ready for a potential blow up.

Basically it is a measure of the meters ability including the test probes, to withstand the peak voltage levels that occur.

 

 

This reminds me of a case of professional stupidity from a huge number of years ago.

An idiot approached an 11kv cabinet with the intention of doing a few continuity checks with his AVO 8.

The cabinet had not been locked off.

There was a welding arc-like flash and the meter went into orbit.

The man was projected across the room landing in a heap of semi consciousness.

The man was OK after a brief stay in hospital. The cabinet was fine having passed it's test.

All parts of the AVO 8 were finally located and consigned to the rubbish bin.

 

Moral is obvious.

[bluejets]

On 4/30/2024 at 10:25 AM, Muhendis said:

professional stupidity

I'd have to say, drop the first bit.

How anything/anyone survived is unbelievable.

What's even more unbelievable is the original access.

Obviously the cabinet in a bad state of repair.

 

Bit like this web site that won't allow/recognise "like" tic.

Edited May 4 by bluejets

[Muhendis]

2 hours ago, bluejets said:

I'd have to say, drop the first bit.

How anything/anyone survived is unbelievable.

What's even more unbelievable is the original access.

Obviously the cabinet in a bad state of repair.

 

Bit like this web site that won't allow/recognise "like" tic.

Yeah.

There are procedures to control this sort of work.

The site was under commission so commissioning procedures should have been in place but I guess things were a bit lax.

The cabinet should have been locked off when under powered conditions.

It wasn't so the guy assumed it was safe.

The guy was lucky to survive.

Apparently there was an arc which occurred as the meter probe approached the contact point.