I have single light switch, three romex in ceiling box, TWO LED panel lights are running out of ceiling box. I want to add TWO more LED drop in panels. I need to know HOW to add these. Breaker Box turns off electrical outlet, stairs, BOTH LED lights, AND additional lights in other basement room. HELP PLEASE!
First and foremost, you need to obtain an electrical permit from your local taxing authority. The permit and inspection in my locale would run ~$250. Then, and only then, can you shove more wires in that overstuffed ceiling box.
Do you have single-phase or two-phase electric service?
Assuming you want the new ones to operate off the same switch, then you wire them in parallel with the existing light, connecting black to black, white to white, bare ground wire to bare ground wire. Where you connect into the exisiting wiring depends on where the new ones are going and how the existing has been run. Most times you'd connect at the existing box for the light fixture that's there.
Next issue is how many wires are already in that box and how many it's allowed to have per code. Typically they accommodate 6 to 10, there are wire fill tables that show how many wires are allowed for the common box sizes. You have three romex going in already, if they are each two conductors, then that's 3x2 conductors + 1 ground =7. If you add another romex to go to the first new light, that would make it 9. So that box is supposed to accommodate at least nine 14g wires, assuming it is 14g. Find the max count in the tables for your box, as long as it's 9 or more, you're OK. Romex goes into old box, run over to first new box, daisy chain to next one. Buy old work boxes for the new spots, they are made to install into existing ceilings.
The typical 4" octagon box used for ceiling lights is 1 1/2" deep and is full with 7 conductors. (3 14g Romex) If by remote chance they used a 2 1/8" deep box, it holds 10 14g. conductors.
Hire a "sparky" to have it tone properly and safely. Pretty difficult to see through the ethernet exactly what setup you have.
No such thing as 2 phase
There is (was). What is split phase in most of the US is mistakenly called 2 phase by some. However there really is 2 phase. I hop ewe don't have to go through the same old 400 postings about this.
Two-phase electrical power was an early 20th-century polyphase alternating current electric power distribution system. Two circuits were used, with voltage phases differing by one-quarter of a cycle, 90°. Usually circuits used four wires, two for each phase. Less frequently, three wires were used, with a common wire with a larger-diameter conductor. Some early two-phase generators had two complete rotor and field assemblies, with windings physically offset to provide two-phase power. The generators at Niagara Falls installed in 1895 were the largest generators in the world at that time and were two-phase machines. Three-phase systems eventually replaced the original two-phase power systems for power transmission and utilization. There remain few two-phase distribution systems, with examples in Philadelphia, Pennsylvania; many buildings in Center City are permanently wired for two-phase[2] and Hartford, Connecticut.[3]
Thanks for explaining this, Ralph. ;>)
They were 25 Hz too. Wasn't aware there were any"shaker" transformers still left in use. Noisy as heck - particularly the old Niagara 25hz stuff. Transformers heated up from the friction of the laminations rubbing against each other if they were not oil filled.
No real reason the permanently wired" 2 phase buildings cannot be connected to "split phase" 120/240 supply. Be a bugger sourcing motors - things like AC unis, driers, etc for an EXTREMELY limitted market.
If you had that hope, why did you take the troll bait?
You start off with the wrong assumption that because one particular system of two phase was called two phase, that means that defines what two phase means. To do this right, you first need to define what an N phase power service would look like. Hint: It's not limited to 90 degrees phase difference. I have defined it in the past, no one else has.
So, here are your questions. Let's take your second example of what you say was the old two phase power, ie 90 deg phase difference, three wires with a common return. I changed the phase difference to 70 deg by rotating one of the windings on the generator. Are there still two phases there? Now I change it to 179 deg, are there still two phases there? I change it to 181, are there still two phases there? I change it to 180 deg, are there still two phases there? And how is the latter any electrically different than the
3 wire 240/120V service going into a home? Describe how I could tell from the panel in your house which of the two I had, how they are electrically different, how they behave differently?This is based on semantics without definitions and reliance on what something was historically, not electrical engineering. Would I call
240/120V, two phase? No, because it's not commonly referred to as that, but that does not change the fact as to what's actually there, you have two 120V sources that are 180 deg out of phase with each other.
He knew you would bite.
Are they 180 degrees? or 120 degrees. Most AC is distributed as three-phase power. Each neighborhood here gets one of the three phases from the the power yard where the incoming three-phase 115kVAC is transformed to
21kVAC or 12kVAC (depending on age of neighborhood) for distribution. That means the two hot conductors at the service entrance are drived from two of the three distribution phases, which would make them 120 degrees apart. That phase is split using a grounded conductor (AKA Neutral) into two 120VAC circuits.
Wrong again, I ignored it. I ignored it after Clare took the bait. It was only after Ralph made his detailed post that I replied.
The 240/120V service into a house is two 120V sources that are 180 deg out of phase with each other. That's how you get 240V between the two hots.
Most AC is distributed as three-phase
I see the typical residential transformer connected with one high voltage lead going to one primary, not connected across two. I assume the other side is tied to a primary neutral.
That phase is split
No argument there. The issue is what you then have, what it looks like, what it is, how you describe it. Go through the simple exercise with questions I posed for Ralph and try to explain the obvious holes. When you treat 180 as just another phase difference, a special case if you will where the phases are directly opposite, you can answer all those questions easily. If you claim otherwise, then you wind up wandering in the wilderness. Which is why they won't answer it, step by step.
Not so. The 240v service to the house (from the pole pig if you have one) is one phase of the three phase distribution.
The pole pig takes the 21KVAC (for example) and transforms it to 240VAC.
The grounded conductor starts at the dist transformer, pole pig or service entrance (a grounding rod (or collection thereof)).
That's certainly not typical. We're fed from a 12kv primary (two current carrying conductors) which is transformed to 240v for distribution to a dozen or so homes. All underground from the nearest substation to the distribution transformer and underground (direct burial) to the service entrance.
There's no need to distribute the grounded conductor (AKA neutral), by definition.
Aerial installations may include the grounded conductor for safety reasons or to help support the cable(that's why there are three wires twisted to most standard pole-pig based service entrances), but it will be grounded again at your service entrance anyway.
You've certainly noticed that there are two terminals on the pole pig each for the primary and secondary - that's what provides you with 240v; the grounded conductor isn't passed through the transformer (but it may ground the pole pig can if it's metallic).
That does not change the fact that it is in fact two 120V sine wave voltage sources that are 180 deg out of phase with each other. That is what you get from a center-tapped transformer. That is exactly what it looks like and what it is. Two voltage sources:
120 Sine(wt) 120 Sine(wt + 180)
It's very typical here, transformer on a pole, connected to one of the three primaries.
Here is an example:
All underground from the nearest substation to
IDK what you mean by "distribute". There is a neutral from the transformer to the customers and with transformers like that pictured, there is a neutral on the primary side also.
Obviously not on all transformers, not on most pole transformers here. Here are some more:
All of which is irrelevant, of course to what you have coming in on the house 240/120 service. Why don't you answer the simple questions I posed in the example of Ralph's two phase service?
We have just two wires from the power company on the poles for single phase power in my area. It looks something like this:
I guess the power company's hot line is actually 13,000 volts plus a bit .
And sometimes I see just one primary going down a road too. Just depends on what the current loads and expected loads are. That's a good picture of exactly what I was describing, very common here. Pole transformer connected between one primary and the primary neutral. I'll have to look more around here when out, see if I also see some transformers connected across two primaries. There are pictures of that, which Scott was describing, online.
I should have stated that was not my opinion, but a copy and paste from Wikipeaia.
I don't intend to get into a discussion over this, Just wanted to point out that by definition there is/was 2 phase in a few parts of the US. It does not matter what anyone says, there is a certain definition for 2 phase.
Just like the bianary number system there are 10 types of people. Those that understand and those that don't.
No, most residential power is derived from a single phase of the 3 phase distribution system. The primary of the branch transformer is accross ONE phase of the ncoming power,and the secondary is center tapped - providing a "split" phase where each side of the service is
180 degrees out of phase with the other - making the voltage of the two phases additive.When derived from 2 phases of a 3 phase supply you get 120 and 208 (the sum of 120 degree out of phase)
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