Voltage neutral to ground at pool pump?

[ritelec]

Hello.

Most recently I've been reading here and there about stray voltage and possible degrading neutrals.

Well I "think" I finally ran into it.

Went to check a 240v pool pump that's not working.
The time clock is 208-240v and the pool man say's he's been have problems with this 240v motor (been burning out ??).

All the exterior wiring is down low.
At the external time clock/motor, It's all rusted up. there are 2 boxes against an outside wall before the clock to the motor (1 gang fs).
From the first box there's a pvc conduit feeding the second box (2nd box has switch to clock/motor) and a conduit going out of the bottom somewhere (I kinda felt by sliding/squeezing my hand down in there).
I can't get to the first box at all as someone built a planter in front of it. At the second box (which also has the planter in front of it) I was only able to get to enough to pry and break off the cover.
It looks like a old single pole switch as one side I can see has no terminals on it and I can vaguely see a red and a white conductor in the box (thhn).

It continues from that box to the time clock thru pvc and sealtight (partly buried and not sure if there was/is a black wire) and in the time clock is a red-white-green.

At that clock location, I'm reading ~ 109v red to white, ~ 109v red to green, 20v white to green.


The service is overhead, to a 400a ct cabinet, through and 2- 200 amp panels.
The voltage at the panel is phase to phase ~ 219-209. Hot to neutral ~ 110-98.

So I think the pool pump never had the 240v as the pool man says it may have.
And Voltage is low.

My thought is to bring a new circuit ( 2 pole gfci protected) to the pool pump,
and safe off the existing circuit at the 2nd switch location and leave that circuit alone (as I don't know what else if anything the existing circuit is feeding), or maybe scope it out some more (?).


As far as voltage, is it low at 220-110 (and lower)? Should I get in touch with the power company?

My neutral and ground question.

At the existing time clock location, the 20v neutral to ground. Why is this?
Wouldn't testing those wires be the same as holding my tester on the neutral/ground terminal bar? Or, am I assuming that the ground at the pool time clock is going straight back to the panel bar, but it may actually be finding a different ground path (and also the one going back to the terminal bar)? Is that why? Does it have anything to do with a Bad utility neutral?

Thank you

 

[ptonsparky]

Sounds like the planters need to go away. Disconnect source and load. Meg wires. Check voltage at source and confirm with utility exactly what you are supposed to have. 240 vs 208.

Bad wires any where in the vicinity of a pool can cause problems. "Vicinity" is subjective.
Leave no planter unmoved.

 

[kwired]

Hello.

Most recently I've been reading here and there about stray voltage and possible degrading neutrals.

Well I "think" I finally ran into it.

Went to check a 240v pool pump that's not working.
The time clock is 208-240v and the pool man say's he's been have problems with this 240v motor (been burning out ??).

All the exterior wiring is down low.
At the external time clock/motor, It's all rusted up. there are 2 boxes against an outside wall before the clock to the motor (1 gang fs).
From the first box there's a pvc conduit feeding the second box (2nd box has switch to clock/motor) and a conduit going out of the bottom somewhere (I kinda felt by sliding/squeezing my hand down in there).
I can't get to the first box at all as someone built a planter in front of it. At the second box (which also has the planter in front of it) I was only able to get to enough to pry and break off the cover.
It looks like a old single pole switch as one side I can see has no terminals on it and I can vaguely see a red and a white conductor in the box (thhn).

It continues from that box to the time clock thru pvc and sealtight (partly buried and not sure if there was/is a black wire) and in the time clock is a red-white-green.

At that clock location, I'm reading ~ 109v red to white, ~ 109v red to green, 20v white to green.


The service is overhead, to a 400a ct cabinet, through and 2- 200 amp panels.
The voltage at the panel is phase to phase ~ 219-209. Hot to neutral ~ 110-98.

So I think the pool pump never had the 240v as the pool man says it may have.
And Voltage is low.

My thought is to bring a new circuit ( 2 pole gfci protected) to the pool pump,
and safe off the existing circuit at the 2nd switch location and leave that circuit alone (as I don't know what else if anything the existing circuit is feeding), or maybe scope it out some more (?).


As far as voltage, is it low at 220-110 (and lower)? Should I get in touch with the power company?

My neutral and ground question.

At the existing time clock location, the 20v neutral to ground. Why is this?
Wouldn't testing those wires be the same as holding my tester on the neutral/ground terminal bar? Or, am I assuming that the ground at the pool time clock is going straight back to the panel bar, but it may actually be finding a different ground path (and also the one going back to the terminal bar)? Is that why? Does it have anything to do with a Bad utility neutral?

Thank you

I have a suspicion you have a bad neutral someplace.

If the time clock is rated 208-240 I don't know why you are having trouble with it, it should not connect to neutral either so a bad neutral is not going to effect it.

Bad neutral should not effect phase to phase voltage. Is this supposed to be 240 or 208 volt system? It sounds like it likely is a 208 volt system, if not then POCO has a problem on their side of things.

 

[DavJ09]

I'd suggest telling the "pool man" to remove the planter boxes, or at least tell whomever he needs to, making the panels readily accessible before you go forward with this.

-- (tapatalk!)

 

[ritelec]

Thank you for the responses .

I did tell the home owner about the planters, voltage, pool.


As it stands. I was given the go ahead to install an new (~) 240v circuit.

The existing circuit I will remove from breaker and safe off at pool area (see if it was feeding anything else then address it later if it was).

I also told the owner I will call utility to find out about why the voltage could be low.

I have a suspicion you have a bad neutral someplace.

If the time clock is rated 208-240 I don't know why you are having trouble with it, it should not connect to neutral either so a bad neutral is not going to effect it.

Bad neutral should not effect phase to phase voltage. Is this supposed to be 240 or 208 volt system? It sounds like it likely is a 208 volt system, if not then POCO has a problem on their side of things.

?

I'm thinking 240V

Do they make a 208/110v single phase system ?

 

[kwired]

Thank you for the responses .

I did tell the home owner about the planters, voltage, pool.


As it stands. I was given the go ahead to install an new (~) 240v circuit.

The existing circuit I will remove from breaker and safe off at pool area (see if it was feeding anything else then address it later if it was).

I also told the owner I will call utility to find out about why the voltage could be low.






?

I'm thinking 240V

Do they make a 208/110v single phase system ?

No it is not possible. But what is possible is to be supplied by only two phases and a neutral from a 3 phase 208/120 wye system.

If you have a neutral problem I can see you having some of the voltages to neutral you have, but you should still have full 240 line to line if you have a 240 system. So unless you have some serious voltage drop issues the POCO maybe has problems with either their transformer or the has low primary voltage to that transformer for some reason - like a malfunctioning regulator on their primary system. Or you do have line to line voltages that are consistent with what you might expect from a 208/120 system, except for the voltage to neutral.

 

[ritelec]

Modified cable assembly?

Modified cable assembly?

For this pump, I will probably take up the code exception on it's wiring methods for pool motors in residential indoor applications.

I will use nm in the interior of the building, then splice inside to mc to come out to hit a switch - clock - motor.

(just a thought though, what if I used uf so I could exit the building rather than the nm and then strip some insulation from some green thhn and slide it over the bare uf ground (?) and eliminated the to mc splice?)

In reading this exception, it's in pool motor (s).

Dose this exception include other pool equipment (heater, light) or "just" motors?


I'm thinking, just motors.

Reason I ask is there's is a gas pool heater. It's a millivolt heater. The pool man is thinking he would be able to tap of the motor ~ 240 in the future for the heater if he wanted. (there is no pool light that I could see).

 

[ritelec]

No it is not possible. But what is possible is to be supplied by only two phases and a neutral from a 3 phase 208/120 wye system.

If you have a neutral problem I can see you having some of the voltages to neutral you have, but you should still have full 240 line to line if you have a 240 system. So unless you have some serious voltage drop issues the POCO maybe has problems with either their transformer or the has low primary voltage to that transformer for some reason - like a malfunctioning regulator on their primary system. Or you do have line to line voltages that are consistent with what you might expect from a 208/120 system, except for the voltage to neutral.

Okay.

I'll get some numbers and make some calls this week and let you know the verdict.

Thank you.

 

[kwired]

Thank you for the responses .

I did tell the home owner about the planters, voltage, pool.


As it stands. I was given the go ahead to install an new (~) 240v circuit.

The existing circuit I will remove from breaker and safe off at pool area (see if it was feeding anything else then address it later if it was).

I also told the owner I will call utility to find out about why the voltage could be low.






?

I'm thinking 240V

Do they make a 208/110v single phase system ?

Installing a new circuit will not fix anything if the voltage is low at the supply side.

I would confirm that this is or is not supposed to be 120/240 or is part of a 208 volt system.

If it is indeed a 240 volt system and you only have 208-219 volts you need to first determine if it is a voltage drop problem or if there is something wrong with POCO side of things. One easy thing to do is to turn off the main and measure voltage as line side of the disconnect. If it is low with no load, nothing you will do on the premises wiring will change this - it is a POCO side of the service problem. Strange voltages to neutral are indicative of a neutral problem, but should be high on one side and low on the other. They should still add up to whatever line to line voltage is, even if it is 75 volts on one side and 170 on the other.


Neutral to ground voltage is another issue. Is your EGC bonded to the service neutral back at the service equipment? If so you will read differences between neutral and ground that is equivalent to any voltage drop on the neutral being measured. Some potential here is normal, but should generally be a pretty low value. Around a swimming pool if equipotential bonding is done correctly you may have voltage between a neutral conductor and "grounded and bonded" objects but should not have any potential between "bonded" objects.

If you drive a grounding probe in the dirt away from the pool area and bring a conductor from it near pool and measure a voltage - you are seeing voltage drop from the neutral in this measurement. This could be premises wiring voltage drop or supply side voltage drop. Remember the utility also has current carrying neutral conductors of their system that are bonded to the same point and your service neutral brings this same point to your service equipment, and the main bonding jumper brings it to all your EGC's.

If you open the service disconnecting means you will lose all voltage drop being contributed by premises wiring. If you are still reading a voltage from neutral to a remote ground probe with the service disconnect open then that voltage about has to be coming from POCO side of things. (But a proper equipotential bonding system around the pool still protects users of the pool from being subjected to this voltage).
Now lift the incoming neutral from the service disconnecting means and the "stray voltage" at that remote probe likely goes away, which further confirms the "stray voltage" is coming from the POCO side of things.

 

[ritelec]

Okay. Thank you.

I will look into it deeper.

But for now, would you agree that a new clean controlled 240v circuit to this area is the way to go also?

 

[growler]

The service is overhead, to a 400a ct cabinet, through and 2- 200 amp panels.
The voltage at the panel is phase to phase ~ 219-209. Hot to neutral ~ 110-98.

When you measure ~98V from hot (phase) to neutral that would tell me something is wrong.

Even a 120/208V systems should have a lot closer to 120V phase to neutral.


You need to get with the power company first off. That ~98V will not even meet their standards.

 

[ritelec]

Strange voltages to neutral are indicative of a neutral problem, but should be high on one side and low on the other. They should still add up to whatever line to line voltage is, even if it is 75 volts on one side and 170 on the other.

Thank you.

I will perform the suggestions.

To note, I did check both phases to neutral looking for something like that, they both measured the same to neutral.

I'm curious about the potential to the bond as you mentioned (which may be just the motor to heater). I'm guessing the house may have been built in the seventies.


Quick question.
Different pool.
I installed some gfci two pole breakers (seimens). The breaker had some type of notice that came with it about not installing it on pools installed before 1965.
I did a google search but not much of an answer.

How different were pools installations in the 60's?

Thank you

 

[J.P.]

I doubt the voltage is that low on the whole house.
I am assuming that the pool is on the main house panel?

what is your source voltage?

Why do you need a neutral with a 240v pump?

Check for loose connections/corrosion, you may even have a poorly installed circuit to the pool house with broken insulation and it's leaking into the ground.

 

[kwired]

Okay. Thank you.

I will look into it deeper.

But for now, would you agree that a new clean controlled 240v circuit to this area is the way to go also?

Probably not. If you are supposed to have 240 volts you need to find out why you don't have 240 volts. If it is because of voltage drop on the circuit in question then that solution will work - provided you run larger conductors to compensate for VD. If the voltage is low at the supply end, running a new circuit will not change that problem.

 

[growler]

The service is overhead, to a 400a ct cabinet, through and 2- 200 amp panels.
The voltage at the panel is phase to phase ~ 219-209. Hot to neutral ~ 110-98.

I doubt the voltage is that low on the whole house.
I am assuming that the pool is on the main house panel?

what is your source voltage?

The voltage may not be that low for the whole house but from the way he wrote it in the first post it sure sounded like.

Phase to phase ~219-209. I assumed those to be the two main panels.

 

[ritelec]

The voltage may not be that low for the whole house but from the way he wrote it in the first post it sure sounded like.

Phase to phase ~219-209. I assumed those to be the two main panels.

Yes two mb panels from a ct cabinet and trough.

On docket for Tuesday.

:- )

I heard judge Judy is a nice person and oprah s not.

 

[ritelec]

Update 6-5-14

Update 6-5-14

Hello all.

Went to job on Monday.

First thing I did was check voltage at both panels.

~ 195 v hot to hot, ~ 97 v hots to neutral.

Turned off two main breakers, same voltage. I asked owner to call utility to come out.

Did work, and did not want to turn on new pump but all other loads (like 8 ac's condensers) were on , so about 2 pm., took voltage reading and was at 220v.

Utility did not show.

I called utility yesterday. They said they would send someone out. Got a call from the owner that utility came out and voltage was good.

I called utility back to mention the fluctuation (again). They said they would note it and send someone out. ???

Not knowing what to do next, I went to a local division of the utility company and found out the inspector for that area. I called the inspector and left a message.

A few more attempts then I may let it go ??


The original voltage readings I took.
Turns out it was a 240 v circuit not 120 v ( even though not the right voltage) as I originally thought. It was a 2 pole switch (not single pole as I thought)
that I was able to get to after the circuit was off and ripping it out with a craw bar (and I located the conduit, and circuit in the panel which I "should have" seen when I was there Friday).

The switch was all buggered up and rotted so thats why I had 110v between legs and voltage white to ground.( ? I figure a switch is either opened or closed, but I wonder why a buggered switch would give a "different" voltage reading? But it's not the first time I've seen this so I guess that's just what it can do sometimes...?)

I don't like alot of code changes and don't care for Identifying the white wire if it is a hot. But in this case it would have really helped and I now see the good in it.

So, at this point. I safed of the existing circ (underground, good or bad) Brought a new gfci protected circ. to the pump, and am waiting to hear from an inspector.


Thanks all for all the input.

 

[J.P.]

Just for giggles do you have a different meter to try out when you are measuring voltages at the panel?

If it was that low I would think the utility would catch and repair it. Maybe not though.

Maybe pull the meter cover and check there, then pull the meter and put a wrench on all of the customer connections. Check for corrosion ect....

 

[kwired]

Hello all.

Went to job on Monday.

First thing I did was check voltage at both panels.

~ 195 v hot to hot, ~ 97 v hots to neutral.

Turned off two main breakers, same voltage. I asked owner to call utility to come out.

Did work, and did not want to turn on new pump but all other loads (like 8 ac's condensers) were on , so about 2 pm., took voltage reading and was at 220v.

Utility did not show.

I called utility yesterday. They said they would send someone out. Got a call from the owner that utility came out and voltage was good.

I called utility back to mention the fluctuation (again). They said they would note it and send someone out. ???

Not knowing what to do next, I went to a local division of the utility company and found out the inspector for that area. I called the inspector and left a message.

A few more attempts then I may let it go ??


The original voltage readings I took.
Turns out it was a 240 v circuit not 120 v ( even though not the right voltage) as I originally thought. It was a 2 pole switch (not single pole as I thought)
that I was able to get to after the circuit was off and ripping it out with a craw bar (and I located the conduit, and circuit in the panel which I "should have" seen when I was there Friday).

The switch was all buggered up and rotted so thats why I had 110v between legs and voltage white to ground.( ? I figure a switch is either opened or closed, but I wonder why a buggered switch would give a "different" voltage reading? But it's not the first time I've seen this so I guess that's just what it can do sometimes...?)

I don't like alot of code changes and don't care for Identifying the white wire if it is a hot. But in this case it would have really helped and I now see the good in it.

So, at this point. I safed of the existing circ (underground, good or bad) Brought a new gfci protected circ. to the pump, and am waiting to hear from an inspector.


Thanks all for all the input.

One problem here is you don't know just what or where POCO took any readings. Your readings are consistent enough though, approximately 80 percent lower then what nominal should be for line to line and line to neutral that I suspect a problem somewhere in the supply and not in the premises, and assuming you are measuring at the service equipment. Are both lines to neutral near this 97 volts? More reassurance if they are.

A bad connection somewhere on the secondary side of the transformer would usually only be in one conductor and would throw voltages out of balance - not reduce all of them by the same magintude, I still think it is a primary side of transformer issue, as that would change all secondary voltages of a single phase transformer by the same magnitude.

 

[ritelec]

Talked to poco inspector this morning (I hate saying or writing poco, but)

I mentioned the voltages that I mentioned to you. And a history of whats been going on this week. (thank you, I also mentioned about disconnecting premises wiring and getting the same voltages as with premises wiring connected).

He is going to go there today to unlock and look in the ct cabinet.

He also gave me a number to call (which I did) to "create a job" for the low voltage.

They will send an engineer out there to examine how many other homes are off this transformer, and to hook up some equipment to monitor the voltage.