How low is too low?

[K8MHZ]

On a t-shooting gig I measured 111 volts at the kitchen receptacles with a load. The load was the range and all the burners on high. Coming out of the meter, I had a low of 113 volts. I checked at the conductors, not the terminals.

The drop is old single conductor and is tied in using split bolts. At first I thought this was a hack job, but looking at the other end of the drop I saw split bolts up there as well. I noticed that all the old drops on that line were connected using split bolts. They once had tape on them, but all that is left of the tape is bit's and pieces.

In the perfect world I would bucket up to the drop and check the voltage there, but that ain't happening.

I at least want to take a look into the meter base. This is in a strictly enforced residential area.

Is 113 volts low enough to get the POCO out to look at things and possibly change the old rat wire out with new triplex?

While that is happening, I could take a peek at the meter socket. Due to the weather here, bad connections in meter bases are not all that uncommon.

 

[satcom]

On a t-shooting gig I measured 111 volts at the kitchen receptacles with a load. The load was the range and all the burners on high. Coming out of the meter, I had a low of 113 volts. I checked at the conductors, not the terminals.

The drop is old single conductor and is tied in using split bolts. At first I thought this was a hack job, but looking at the other end of the drop I saw split bolts up there as well. I noticed that all the old drops on that line were connected using split bolts. They once had tape on them, but all that is left of the tape is bit's and pieces.

In the perfect world I would bucket up to the drop and check the voltage there, but that ain't happening.

I at least want to take a look into the meter base. This is in a strictly enforced residential area.

Is 113 volts low enough to get the POCO out to look at things and possibly change the old rat wire out with new triplex?

While that is happening, I could take a peek at the meter socket. Due to the weather here, bad connections in meter bases are not all that uncommon.

When we are looking for problems we check at the service head first then the meter socket, and then the line side of the main, before we call the poco, 113 or 110 can be a common reading, depending on the time of day, distance from the sub or main distribution station.

 

[growler]

On a t-shooting gig I measured 111 volts at the kitchen receptacles with a load. The load was the range and all the burners on high. Coming out of the meter, I had a low of 113 volts. I checked at the conductors, not the terminals.

Is 113 volts low enough to get the POCO out to look at things and possibly change the old rat wire out with new triplex?

That 113 V that you speak of, is that with a load or without a load?

If you started out with say 120V and it droped to 113V because you turned the range on that would indicate a problem.

You are looking for "voltage drop" as a potential problem and not the normal operating voltage being low. The power company will probably accept 113V as an acceptable operating voltage but a substantial drop anywhere under a minimal load would indicate a loose connection.

Do the lights dim when the dryer motor starts? Do the lights dim when anyother substanial load is added?

 

[K8MHZ]

That 113 V that you speak of, is that with a load or without a load?

If you started out with say 120V and it droped to 113V because you turned the range on that would indicate a problem.

You are looking for "voltage drop" as a potential problem and not the normal operating voltage being low. The power company will probably accept 113V as an acceptable operating voltage but a substantial drop anywhere under a minimal load would indicate a loose connection.

Do the lights dim when the dryer motor starts? Do the lights dim when anyother substanial load is added?

The voltage drop measured at the last place upstream that I could, showed a drop of around 6 volts using the range and burners (5 or 6kW?) as a load. This was not consistent. Sometimes it would rise to around only a 4 volt drop.

 

[K8MHZ]

Minimal load reading = 118.9 volts

Moderate load reading = 113 volts.

 

[shepelec]

6v seems like a big drop. I think National Grid, where I am, allows 5% before they will do anything. What kind of load?

 

[growler]

Minimal load reading = 118.9 volts

Moderate load reading = 113 volts.

OK, I have gotten the power company out on jobs like this to hook up their known load and see if the drop is within their tolerance.

That's enough that it would make me suspicious of a loose connection or the transformer is a long way from the house. I have had it go both ways, at times they find a loose connection and other they just say the tranformer is quite a ways out and it's within tolerence.

We can't work on their equipment so if it's good enough for them then we just have to accept it.

I would call it in as a suspected loose connection and see if you can meet them to check out the meter base. Sometimes things are easy and at others it takes and act of God to get them out. We can only do what we can do and that's whatever we think is right. At least the customer feels better if the power company is OK with it.

I also guess that if you can get close enough to the conenctions you could use an IR thermometer becasue if the connection is bad it's going to be hot as a two dollar pistol when under a real load.

 

[e57]

Minimal load reading = 118.9 volts

Moderate load reading = 113 volts.

And where is that taken at? The meter/main - or the farthest outlet.

This is the FPN under 210.19(A)

FPN No.4: Conductors for branch circuits as defined in Article
100, sized to prevent a voltage drop exceeding 3 percent at the
farthest outlet of power, heating, and lighting loads, or
combinations of such loads, and where the maximum total
voltage drop on both feeders and branch circuits to the farthest
outlet does not exceed 5 percent, provide reasonable efficiency of
operation. See FPN No.2 of 215.2(A)(3) for voltage drop on​

feeder conductors.

That said there is quite a lot that could contribute to this - and it mainly depends on what is at the front end of the circuits - like say at the feeder or service. The distance and wire guage of the conductors, and it's load.

If it is a POCO issue it will be present there at the main/meter - if it is an interior problem it will not... The both need to be compared - with and without load. If it is a connection issue - I suggest an IR thermometer to help locate it - under high load a loose connection will produce heat... But it may just be a size/distance/load issue - try a voltage drop calculator and see what you get...

 

[e57]

Here is a better one... (It's very nice...)

More from them...

 

[iwire]

Here are some recommended values.

Try giving the power company a call. I did for my own place and they came out in just a few hours they pulled the meter put in a tester and in just a few seconds verified there was a bad neutral connection on the supply side of the meter. Later in the day one of their trucks came by and fixed it.

 

[K8MHZ]

I love this forum!!!

I did call the POCO and the engineer for the area was on vacation 'till Monday. I have worked with this particular engineer before and would rather wait until he gets back than to get a fill in.

Thanks, iwire, for the chart. A copy is going to end up in my folder.

I apologize to all for the somewhat lackadaisical presentation of the issue. I did not go out there to analyze a voltage drop, I went out to fix a dishwasher for an elderly lady related to a friend of mine. I also had to leave at a certain time to get to a doctor's appointment. I know I should have had values of no load versus a known (not just guessed) load but there wasn't time and I kind of had to shoot from the hip.

Thanks to all.

 

[PetrosA]

I'd recommend finding out what that particular POCO considers it's tariff reading and how it's read. Here, PECO established 232V between legs at the meter socket or main as the residential tariff minimum. They won't accept a problem call if I report one leg reading low unless I'm calling in a bad neutral.

 

[K8MHZ]

I'd recommend finding out what that particular POCO considers it's tariff reading and how it's read. Here, PECO established 232V between legs at the meter socket or main as the residential tariff minimum. They won't accept a problem call if I report one leg reading low unless I'm calling in a bad neutral.

If I had evidence that the fluctuation was a compromised neutral, there would be no problem getting the POCO out, but that is not what I read.

It does not seem that there is a chance of over voltage so I don't see this as a critical issue.

I checked for and did not see any signs of conductor or connector over heating.

I should know more on Monday.

 

[satcom]

Reading this post made me wonder what utilities companies would not reply to a customer complaint, our area utilities respond to every customer concern, and then if they find a problem not related to their supply side, if the problem is on the customers side, they will notify the customer to contact an electrician.

 

[LarryFine]

After asking the usual few narrow-it-down questions, I usually suggest a caller contact the POCO before paying me to provide a service call if the evidence points toward a line-side issue. If it ends up they need one of us, they're usually appreciative of my honesty.

 

[PetrosA]

Reading this post made me wonder what utilities companies would not reply to a customer complaint, our area utilities respond to every customer concern, and then if they find a problem not related to their supply side, if the problem is on the customers side, they will notify the customer to contact an electrician.

I get the impression that PECO won't come out for a lot of calls unless an electrician calls it in. It even seems to depend on how an electrician calls it in whether or not they'll get a crew there fast or slow. I make sure the service rep takes down voltage/amperage readings, how and where I obtained them, load or no load etc. and I give my name and telephone number for them to pass on the the crew doing the repair. The longest any of my customers have waited was second day for a crew. Other electricians I know weren't able to get a crew out at all, but I suspect they weren't reporting the issues in a competent manner.