I noticed the aforementioned diagram shows a red and black coming out of the transformer:
Interestingly, I see a ground on both sides of the transformer.
I wonder which ground it was that I remember seeing going down every third power pole?
There is only one earth/ground to neutral connection allowed in a power distribution system unless a new service is established. The ground to neutral bond is only allowed at the point where the service is established. This would require a dedicated ground rod for the panel, and no sharing of grounds/hots/neutrals of other panels. Your meter-main is where the service to your residence is established, and that is where the earth/ground bond is made.
This is done to keep good continuity between the earth grounds. They perform a resistance check of the soil and determine the proper spacing of grounding electrodes to keep the potential equalized, and also to ground the neutral wire (if present) strung along with the power lines to eliminate transient/induced voltages. How many of these poles have transformers on them or other utility devices?
Don't worry about it. My monitor is on its last legs and some things just don't show up right, nor clear. Sometimes it does not turn on at all. It is old, and I want to relocate where I do my computer work and get something mondo!
That makes sense. I was going off of memory with "every third pole". I remember, as a kid, wondering what 'all those wires' were. Over time, I learned:
a) The three high wires were the three phases of power distribution. b) The low thick cables were the telephone (and then later, cable). c) The house only got two wires (now I know it's from the xformer). d) The transformers got two of the hot wires (I had thought). e) The ground was the return back to the power company (figuratively). f) Every third pole had a ground to ensure the power company got it.
From the aforementioned diagram, I'm realizing "d" above is wrong:
Do I interpret the diagram correctly, that, of the three hot distribution lines on the power poles (each 120 degrees out of phase with the other), the transformer does NOT get two of those, but, it gets only one hot out of the three on the pole?
I hadn't realized only one earth ground was allowed, and, that it had to be at the service entrance.
I would have thought the more grounds, the better.
So thanks for advising me on that.
With the power off (and ideally the switch padlocked shut) you might be able to loosen these screws, and wire brush the wires, screws, inside the connection, etc.
There used to be grey stuff sold, for protecting aluminum connections. Noalox (NOAH=locks) is one such. Might also be called Nocorode. (NO corrode.) I'm not sure if it's any good. I've seen it in the electrical department of pretty much any hardware store.
I don't know if a coating of heavy grease can be used, or which grease. I know we used to use car wheel bearing grease for auto electrical connections like battery posts.
So the power comes in to this panel and then the other two panels have most of the breakers for the house. This panel has just a few breakers for a few circuits.
It's not the typical settup. But as long as it's done correctly, I don't see why it violates anything.
That's right, the neutral is grounded periodically, which is what I said.
The utility neutral is grounded just like the neutral in your house is grounded. Just like you call the wire from your panel to the ground rod, water pipe, whatever the "ground", not the neutral, you call the wire grounding the utility neutral a ground wire.
No, you won't be killed if you treat them differently. They are different. Treating them the *same* is what can get you killed.
That it runs once a week is not a sign of the generator being dumb. I still bet that it runs once a week as a self-diagnostic, not to charge the battery. For one thing, how would it know that 20 mins is the correct amount of time to charge it? It's also kind of inefficient to take current out of a battery, just to charge it, when you don't have to.
Nightcrawler raised the issue that some cheaper generators might not keep the battery charged off of the utility AC. That may be true, but I've seen typical home Generacs and they do keep the battery charged off utility AC. They also have a charging circuit that charges the battery when the generator is running. But the once a week cycle is to exercise the generator, keep the brushes from oxidizing, verify that it runs OK, and if it doesn't it sets a code, an alarm, etc so that you know the gen is kaput before you need it.
What yours exactly does, none of us here know.
I have electrical dielectric in a can that oozes out like vaseline when you tilt the tube. Would that work?
I just realized that the power pole, which has only three wires on it, must be adding the fourth to the ground only at the transformers.
Not an electrician, here. But, yes, I'd use that on my own panel.
Be careful not to extrapolate from this to subpanels. In a subpanel downstream of the service entrance, the grounded (neutral) and grounding conductors must _not_ be connected to the same busbar, and the grounded and grounding busbars must _not_ be bonded together, nor may the grounded busbar be bonded to the panelbox.
scott
Maybe I did not write that correctly. You are only allowed to make one earth to neutral "bond" (termination) per service, and this shall be made at the point of service entry (meter-main). All circuits associated with this panel must return to this panel. Sub-panels are not "services", and there is "not" to be a earth to neutral "bond" at these locations. If bonded to ground at these locations, then the ground becomes a current carrying conductor that operates in parallel with the neutral.
As with the meter-main, all circuits that originate from the sub-panel must return to the sub-panel. However, you may install a ground rod for any sub-panel or device, as you wish, as long as it is installed via proper wiring methods and the complimentary earth ground shall not be bonded to the neutral unless the circuit originates from the service entry. A ground rod may be installed, a water pipe bond, a gas pipe or other earth bond may be made without returning to the panel as long as the connection to a device does not interfere with the proper wiring methods from said devices power supply. In industrial settings it is often found that a device will have a ground rod, or two, installed with a large gauge wire terminated on the metal frame of the device. This wire is not "electrically" connected, but is not necessarily isolated from the service ground, at the device, either. Though, sometimes it is.
Modern code requires two ground rods, anyway. You need to learn how to separate what a ground is, and what a neutral is, in your mind. A neutral conductor ideally does not carry current, but this is not an ideal world and it is almost impossible to wire a structure with a perfect balance, at all times, so there will be current on the neutral. Sort of why I think it is stupid that they allowed the "grounded conductor" (the neutral) to be called a neutral. It used to be called "the Common". Calling a current carrying conductor a neutral is like saying fire is water.
The only purpose of the ground wire is to provide a direct shunt path for the circuit breaker in case of a "hot" to chassis fault, and to perform what is called equalizing potential. Meaning that all exposed (even non-exposed) conductive surfaces have the same potential (voltage/charge). Works in theory, but anyone who has gotten a zap at a water faucet knows that systems may fail, after time.
Equalizing potential is the concept that it is not possible to induce electric flow between two points that have the same electric state. This includes static, DC, and AC electricity. Put two wires on the positive of you car battery and touch them together. What happens? Put two single pole circuit breakers in a panel, inline, left to right, sharing the same bus. Wire the breakers together and turn the breakers on. What happens? Get yourself on a high tension line (without getting zapped) and hand over hand along its length, staying 15'+ from any ground or opposing phase. What happens?
Stand next to a high tension tower, say one foot away and have the ground ring somehow fail for this tower. Take a step. What happens?
It is more typical than you might think, nowadays. Some locales might be so old that you will not see this, but on most new construction over the past 20-30 years, this is quite common. The meter-main will supply to sub-panel(s) that will branch out closer to the area that is supplied. This is even more prevalent in multi-level housing. Usually a standard installation for an average house will have the meter-main, with only a circuit breaker, and a sub-panel located inside the house, usually a closet. Of course, the code requirements are soon broken since nothing is supposed to be in front of these sub-panels, but in a residential setting such things are overlooked.
Often times, as in Danny's case, and with 200 amp services, in general, the meter-main acts as both a distribution panel, and a load center for external devices. Some contractors like to keep all of the exterior outlets at the meter-main panel board, plus anything else that is outside of the residence. Detached garage, out building, gazebo lighting, garden/walkway lighting, miscellaneous outlets popped up around the yard, and sometimes irrigation. Though, usually this is kept in the garage, but still might be fed from the meter-main panel board.
My place is well over 40 years old and only has the meter and associated main breaker outside, with a sub-panel inside.
Thanks. It is for electrical work, but I bought it at the auto parts store 'cuz it's for car electronics (low voltage).
In trying to better understand the "why" of this, I found on the net this really nice (I think) summary, with clear & obvious pictures:
I saw pictures of that exact topic over here:
Funny you should mention that, because I couldn't make out what the wording was in pencil for the one 120V baby braker, but, it might very well be trying to say exterior lighting in some way. Here's a picture of the pencil annotations.
The one I can't make out is the bottom right 120V 15A circuit breaker:
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