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Names of Parts on Electric Pole
- bombcar 3y agoA fun rabbit hole to dig into is how a transformer can have one wire going in, and three going out to your house. Where does neutral/ground go? How does the high voltage circuit complete?
- briHass 3y agoShort answer: they don't. A residential transformer has an input connection to a 'hot' and the neutral line. The neutral connection just isn't as obvious, because it may be to the body of the transformer itself.
- bombcar 3y agoSWER: https://van.physics.illinois.edu/ask/listing/14623 https://van.physics.illinois.edu/ask/listing/14623
- briHass 3y agoSure, but the transformer still has 2 connections on the input (HV) side. The neutral path just doesn't run on a continuous wire all the way back. I think it's interesting that a similar idea can actually be demonstrated in your own home. Because current takes all available paths in relation to their impedance, the household 'neutral', which is also connected to physical ground at multiple points, return path isn't just through the wire itself. The ground connected to your incoming water/gas/UFER will have some small amount of the current your house is using. Most will be on the triplex wire running to the transformer, but a few amps may be on those alternative grounds.
- bombcar 3y agoIf neutral is connected to the physical ground at multiple points you have a quite dangerous electrical fault, and should get it resolved. https://www.mikeholt.com/mojonewsarchive/GB-HTML/HTML/Neutral-to-GroundConnections~20020521.htm https://www.mikeholt.com/mojonewsarchive/GB-HTML/HTML/Neutra... https://www.houzz.com/discussions/2649182/so-why-is-it-bad-to-have-the-ground-carry-the-neutral-load https://www.houzz.com/discussions/2649182/so-why-is-it-bad-t... (Basically, and probably wrong in all the right ways, if you are using ground as neutral somewhere, you can be shocked because a breaker will NOT throw when it should, and you can be shocked to death by a neutral/return line just as easily as a hot line when it is being used.) (This does NOT mean that your single connection to ground shouldn't be multiple ground rods, as you want that connection to be as low-impedance as possible, as it helps to ground out large surges such as lightning, etc.)
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- amluto 3y agoA modern GFCI will trip if you accidentally ground the output neutral. IMO this is a very good thing, in part because it prevents problematic wiring practices like this downstream of the GFCI.
- bombcar 3y agoModern GFCIs are kind of a wonder-device, in that they prevent bad wiring but also make other types of bad wiring safe - you're much better off putting an UNGROUNDED GFCI in instead of miswiring a 3 prong outlet or adapter in an ungrounded box. It's my go-to now to "fix" two prong outlets. https://www.electricallicenserenewal.com/Electrical-Continuing-Education-Courses/NEC-Content.php?sectionID=306.0 https://www.electricallicenserenewal.com/Electrical-Continui...
- jsmith45 3y ago> If neutral is connected to the physical ground at multiple points you have a quite dangerous electrical fault, and should get it resolved. Mostly true, except that neutral will also be re-grounded at the service transformer. The NEC actually requires this (or more specifically it requires it to be grounded before it gets to the building, see NEC 2020 250.24(A)(2)). This is honestly a little weird, as typically that grounding would be before the service point, and thus outside the NEC's jurisdiction. The service point cannot be before the transformer, as only instrumentation transformers are allowed on the service before the service disconnect. But in any case, the utilities code has a similar requirement. This means that neutral current absolutely can go though the bond at the service disconnect, down into your grounding electrodes, though the earth, and out at the transformer's grounding electrode, and up to neutral wire grounding at the transformer. Which is not really ideal. As long as the neutral has not failed, it is not a huge deal, as any interruption in the path would not cause significant voltages or spikes, but instead more current would travel over lower impedance neutral service conductor. It is more of a problem if the neutral service conductor has failed.
- amluto 3y agoNot in California! IMO this practice is dangerous (it intentionally runs current in a path that will divert some of it through the ground), and California has banned it for a long time. In CA, there may be a “primary neutral” that is grounded, but it’s not grounded in multiple places, and the transformer inputs are insulated as if the primary neutral is not grounded. (I think the actual motivation for the ban is that ground currents are dangerous to cattle.)
- bediger4000 3y agoI was not able to find turbo encabulators on this web page. Other than that, very thorough.
- 8bitsrule 3y agoWow. Always hard to find reliable info on the electricity system.
- throwawaymobule 3y agoThis page covers way more than just utility poles. Very cool page, on a strangely named domain.