Bathroom lights are dim, voltage is low?

Yea...its been awhile...the neutral and ground are one when they enter the box..with a ground near box and one at the pole. If the ground between pole and box is poor..or should say neutral/ground....also the pole with trany is blocks away..

Our electrical grid setup is over 100 years old. Codes might be different elsewhere..

That neutral/ground wire from the pole, which is required to be grounded at the service disconnecting means, is considered a neutral between the house and the pole. Very little current actually flows in the ground between the pole and the house. If that neutral wire between house and pole has a bad or broken connection, it will cause wandering voltage on the 120V L1 and L2 conductors.

On the other hand, you could just completely disconnect the ground wire from the ground rod at the house (and the pole) and so long as that neutral wire is still intact, the voltage on the 120V L1 and L2 conductors will still be correct.
 
If ya pull the grounds in the house the neutral wil need to travel all the way back to the pole. its 4 blocks away. We have 2 120v with one ground/neutral in this location. Maybe where you are there are dedicated neutral and ground feeds to house. dunno.
 
If ya pull the grounds in the house the neutral wil need to travel all the way back to the pole. its 4 blocks away. We have 2 120v with one ground/neutral in this location. Maybe where you are there are dedicated neutral and ground feeds to house. dunno.

Yea, the center tap on the transformer on the pole is connected to the house via a neutral wire on that installation. It's NOT going through the ground--the resistance of the ground is way too high for that to work..

We ARE talking about an installation in the USA, right?
 
If ya pull the grounds in the house the neutral wil need to travel all the way back to the pole. its 4 blocks away. We have 2 120v with one ground/neutral in this location. Maybe where you are there are dedicated neutral and ground feeds to house. dunno.

This is pretty typical for overhead primary/secondary distribution in the USA.

For the secondary distribution portion of the pole, some utilities put the neutral in the middle and L1 at the top and L2 at the bottom.

It's better to put the neutral at the top like this utility does, in case the 7200V wire breaks and falls, it will (hopefully) hit the neutral and short out and blow a fuse without damaging the customer's equipment.

If L1 is at the top and the 7200V wire hits it, it will cause severe damage to the customer's equipment and may even cause a fire.

EDIT: It should be noted that this neutral is the neutral for BOTH the primary (7200V) and secondary (120/240V). It's technically an MGN, "multi-grounded neutral" with grounds at each pole and the customer premises. But it would work fine without those grounds, they are more for safety.

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On our 100 year old stuff there are always issues with over voltage from the primary falling onto the secondaries. Too many trees. I change out alot of furnace control boards cause of that. Be well...
 
On our 100 year old stuff there are always issues with over voltage from the primary falling onto the secondaries. Too many trees. I change out alot of furnace control boards cause of that. Be well...

That picture is of a 60-year-old installation. (The transformer in the photo isn't that old, it had been replaced). It doesn't exist anymore. A couple of years ago, the utility came through and put in larger/taller poles with a transformer on each pole, so there are NO secondary distribution wires between poles anymore.

The differences between how utilities upgrade and maintain their infrastructure amazes me. On the one had you've got this utility replacing 60-year-old poles (the same utility has the LOWEST outage rates and highest customer satisfaction of any utility in the Washington, DC metro area--they are a cooperative), and adding more transformers so they are closer to the customer, and on the other hand you have a utility with 100-year-old poles with transformers located a long distance from the customers.
 
Unless they have some unsafe wiring practices going on

I can't think of how a bad ground would cause the 120V legs to wander. A typical ground rod impedance might be 25 ohms (that is what the NEC specifies). That's not nearly low enough to cause the 120V legs to change when it's disconnected--at 120V, 25 ohms is 4.8 amps.

Now if the neutral were broken and the house is on public water, theoretically a "bad ground" could cause the 120V to wander because the water pipe ground is a low enough impedance to substitute for the bad neutral. But the "bad ground" is not the root cause of the problem, the "bad neutral" is.
 
I can't think of how a bad ground would cause the 120V legs to wander. A typical ground rod impedance might be 25 ohms (that is what the NEC specifies). That's not nearly low enough to cause the 120V legs to change when it's disconnected--at 120V, 25 ohms is 4.8 amps.

Now if the neutral were broken and the house is on public water, theoretically a "bad ground" could cause the 120V to wander because the water pipe ground is a low enough impedance to substitute for the bad neutral. But the "bad ground" is not the root cause of the problem, the "bad neutral" is.
Agreed.
 
I worked at a house last year that had a bad neutral (loose screw) between the first means of disconnect to the main panel.

Pretty much every dimmer switch in the house burned. The door bell caught on fire. Several circuit boards from the furnace etc. Fried electronic smell all throughout the house. Lights all over were randomly dimming. The house looked haunted.

I thought I had photos, but I must have deleted them.
 
A neutral problem will cause half of the 120 volt circuits in the house to have higher than normal voltage, which is likely to burn things out. If all the outlets measure low, that is different and likely the primary voltage on the grid being too low.
 
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