Neutral issue - this is a doozy!

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  #1  
Old 03-16-14, 11:35 AM
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Neutral issue - this is a doozy!

Ok I got a good one..

Over time I've noticed that when it's really windy out, there's some flickering in my lights. It wasn't really ever anything I was concerned with, because the town's power system is aging and they are replacing lines and transformers all over the place the past year (we don't have a big power company, it's the city's power department).. So I figured it would eventually get to a point where it would stop...

So yesterday there's a knock at the door, and it's the power company coming to change my whirlygig for a smart meter.. While they were doing that I mentioned the windy issue, and he offered to take a look at the connection up at the pole just to rule it out..

He gets up in the bucket and is staring at the connection for a bit.. Then he gets on his phone and calls someone.. And then he comes down and tells me..


Wait for it...




I have NO neutral connection - AT ALL! And I'm not talking one that broke off, or one that burned away when the pole got hit by lightning a couple years ago.. I mean there was NEVER ONE THERE, and this drop was installed easily 40 years ago. The quadplex (I have 3 phase stinger delta service) is simply tied off to the ceramic donut, and it was never made into a tail to connect to the neutral!!

So he's totally baffled as to how my 120V circuits were even functioning. The only thing I can think of is it was running through the ground rod back to the transformer..

Which leaves me with a burning question..... Could that lack of neutral, and the return path being through the high-resistance ground have been screwing up my meter readings? I've noticed that despite efforts to conserve, my bill has been going up year over year, and considering that the ground has been steadily drying out since I've been here, that makes a lot of sense to me.
 
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Old 03-16-14, 11:39 AM
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Was the ground of the quad hanging on a metal mast ?
 
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Old 03-16-14, 11:52 AM
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Nope.. Ceramic donut hangers on each end. On the house end the hanger is attached to brick.
 
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Old 03-16-14, 11:59 AM
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Using the ground rod(s) and copper water service to supply neutral and ground.

I'll admit..... it's not the first time I've seen it.
 
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Old 03-16-14, 11:59 AM
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Possibly running the ground through the same buss as the neutrals, the house neutrals were seeing the ground and used it instead. Perplexing to say the least. One of our municipalities requires our ground electrode from the ground rod, through the meter base and all the way to the weatherhead. We just have to remember that when we work there.
 
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Old 03-16-14, 01:00 PM
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I think you and PJmax is on the right track and your grounding system was the source back to the transformers. Electricity will find its way back to the source if it can, if it can't, then it will not work.

The only way I can see this causing your electric bill to go up is if current was leaking to ground this whole time, and getting worse. I am surprised everything did work and you were not burning up appliances!

Have they fixed it?
 
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Old 03-16-14, 01:40 PM
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Yeah he attached a jumper up at the pole..

Now I am not up on how electric meters actually meter, but the way I'm thinking about it, if the neutral has to run through a high resistance ground plane on its way back to the transformer, rather than through the wire.. Is that not causing everything on 120V legs to draw more amps to overcome the increased neutral resistance, like putting a resistor in series? I realize the 240v appliances should not be affected, but everything 120V should be..

And as I said, we are in a stage 4 drought, so the ground has been slowly drying up over the past few years.. That would increase the resistance between the ground rod and the transformer even further.
 
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Old 03-16-14, 02:14 PM
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Except that higher resistance will reduce the amount of current flow (amps), not increase it. I would be interested to know what the resistance is between your grounding system and the poles ground is. Your voltage to neutral/ground would however change/drop with the increase in resistance of the earth.

If you measure the resistance of a 60 watt light bulb and a 100 wall light bulb, the 100 watt will have less resistance then the 60 watt.
 
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Old 03-17-14, 08:48 AM
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I know how Ohms law works.. But I can't wrap my head around how increased resistance in the circuit would not cause everything on the 120V legs to use more. By definition, a resistor wastes energy by converting it to heat.. And it is dropping the voltage to a known load, causing it to draw more current.

Am I barking up the wrong tree??
 
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Old 03-17-14, 09:55 AM
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Just wondering here. Do you have a municipal water system? Is so that was acting as a path to your neighbors house as your neutral. If so, the bad/dangerous thing is if someone were to pull the water meter without a jumper in parallel. We had a water dept tech almost killed several years back with just this scenario.
 
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Old 03-17-14, 10:28 AM
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Yes I have municipal water, but the water meter is in a pit in the back yard, not inside the house. There is easily 50' of 1" copper in ground contact between the house and the meter.
 
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Old 03-17-14, 03:44 PM
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The neutral (or ground in your case) only needs to handle the difference in total load (difference in current) drawn by the A leg and the B leg of your service. If the impedance to the ground (earth) via ground rods and buried water pipes was low enough and the two legs were drawing roughly the same load each, you would not notice anything amiss from the lack of a neutral.

A broken neutral returning to the utility pole shows up as unusually high voltage between hot and panel neutral (where all the branch circuit neutrals come together) for one leg and unusally low voltage between hot and panel neutral for the other leg, where the two voltages still add up to about 240.

Loss of the neutral does not in itself cause equipment to draw more amperes but some equipment will draw more amps when fed with too low voltage.

(added later) Yes, the path from your panel via grounding electrode conductor to water pipe out through the water meter to the water main to a neighbor's water pipe and through his GEC to his panel neutral and up his service drop to the utility pole can be a low enough resistance substitute neutral for you so you do not notice anything wrong.
 

Last edited by AllanJ; 03-17-14 at 05:25 PM.
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Old 03-17-14, 04:49 PM
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Hmm.. Yeah I have seen what loose/broken neutrals do.. Which is again why it's so baffling that it's been working for decades without a hitch.
 
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Old 03-17-14, 06:37 PM
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Loss of the neutral does not in itself cause equipment to draw more amperes but some equipment will draw more amps when fed with too low voltage.
This is a great point! So if we look at Ohm's law we know that as voltage goes down, current will go up. However, watts stay the same, and electricity is charged by the kilowatt hour.

But it also seams to me that JerseyMatt is not "braking up the wrong tree" when we think of resisters and "energy wasters". First a disclaimer: This is not my strong area so others might want to check my math.

Short circuit if the ground had 25 ohms of resistance @ 120 volts = 4.8 amps and 547 watts. This means of you short circuited a wire, and your path back to the transformer (the earth) has 25 ohms of resistance, the circuit would only draw 4.8 amps. Not enough to trip a breaker! The earth would need to have a resistance less than 6 ohms to trip a 20 amp breaker and 8 ohms to trip a 15 amp breaker.

Resistance of one 100 watt load @ 120 volts = 144 ohms and .83 amps

Resistance of two 100 watt loads wired in parallel @ 120 volts = 72 ohms and 1.66 amps

Resistance of one 100 watt load and 25 ohms resistance between load and neutral source as was the transformer in JerseyMatt's = 144+25=169 ohms, (Here's the goofy part) 85 watts and .71 amps (note watts goes down)

Resistance of two 100 watt loads wired in parallel @ 120 volts, with 25 ohms resistance between the load and neutral in series as was the transformer in JerseyMatt's. 72+25=97 ohms, 148 watts, 1.23 amps. (again, watts is lower)
 
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Old 03-17-14, 07:16 PM
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Is so that was acting as a path to your neighbors house as your neutral. If so, the bad/dangerous thing is if someone were to pull the water meter without a jumper in parallel. We had a water dept tech almost killed several years back with just this scenario.
And it could be even worse when the gas man pulls the gas meter.
 
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