Education Please

[John.DS99]

I am asking for review of my thinking. my solar system education requires constant oversight.
Below is a picture of a Siemens TL137US Talon Temporary Power Outlet Panel with a 20, 30, and 50-Amp Receptacle Installed, Unmetered Gray.

Apologies for the U.S. centric assumptions such as wire color. I am only talking about 120V 60Hz single phase AC power here.
Please assume correct wire sizes will be used. Making the below description was difficult, I tried to be precise.

AAAA. Utility provides three residential connections, Hot1, Hot2 (these are out of phase by 180 degrees), and Neutral. The ground is a return line to Earth made at the home. At my home it is a pipe driven into the (dirt) ground the meter rests on.
AAA. A primary panel has a connection (is continuous) between the ground and the neutral buss bars.
AA. A secondary panel does not.
A. GROUND (labeled) when hooked up, is a bus that will be continuous with the ground of the Utility and Earth (the conducting conduit that the meter is attached to). There is no Utility Ground wire, it is made using a conducting pole driven into the ground.
B. HOT1 and HOT2 are where the Utility hot connects/inputs to the panel. As a single phase system, these two points are equivalent (thinking-wise). For a 240V panel (thinking-wise) they have 240 volts between them.
B2. HOT1 and HOT2 are 180 degrees out of phase, so using either have 120 volts potential, but between them have 240 volts potential.
C. Power output of 120V 60Hz 50 amps can be made with a circuit consisting of three wires:
- A hot (Black wire) attached to the point at the (yellow star) screw by B1
- Neutral attached to the Neutral Bus,
- Ground (green wire) attached to Ground bus.
D. Power output of 240 volts 50 amps can be made by
- A hot (Black wire) attached to the point at the (yellow star) screw by B1
- A hot (red wire) attached to the point at the (yellow star) screw by B2
- Neutral attached to the Neutral Bus,
- Ground (green wire) attached to Ground bus.

Thanks for your patience and comments.

 

[John.DS99]

I guess no one cared for this homework assignment. After further reading, it seems that my notion of the utility inputs is unclear.

For the U.S., there should be two utility hots that are 90 degrees out of phase so that there is 240 volts between them, so Hot1 could be 120V in and Hot2 could either be 120V in out of phase (for 240VAC) or 120V same phase (for more 120VAC).

I think.

 

[Rednecktek]

180 degrees out of phase, not 90. L1 to N is 120v, L2 to N is 120v, and L1 to L2 is 240v. So yes, you're close in your understanding.

Normally each leg of your source connects to the big lug screw at the end of each bus bar, but in sub panels it is often brought in via a 2 pole breaker with each port on the breaker talking to a seperate bus bar which accomplishes the same thing while also adding in the benefit of a disconnect. If you are connecting your input through a breaker, then you only use 1 breaker for this.

In your example picture, the H1 is coming INTO the bus bar via B1, and going OUT the bus bar vis B3. Likewise B2 is feeding power to the B4 breaker.

If you're trying to bring in power from 2 sources then you need to make sure both inputs are in sync or bad things happen. There's no other reason to have 4 breakers involved.

Now if you've only got a single 120v input you have to take it to a breaker input and connect a jumper wire to either the bus bar lugs OR use a double pole breaker and put the jumper between the two terminals. This allows both legs to be fed for taking off power, but does NOT provide 240v as you suspect.

I hope that clarifies things a bit, I'm not completely understanding what you're asking but it seems you're trying to stuff 4 inputs to the same panel which isn't how it's supposed to go.

Your neutral and ground look fine.

 

[John.DS99]

Thanks Redneck. I believe that the black line out of B1 is going to a 50A circuit. Input from the utility is connected to Hot1 and goes through the breaker to get there.

Utility hot -> Hot 1
The black wires from yellow stars at B1, 2 3 &4 go out to individual circuits.

The four breakers dont provide input to anything. They are normally connected to a different circuit, although the double pole breaker with B1 and B2 could be used in a 240VAC circuit.

The picture is upside down.

 

[John.DS99]

At any rate, I have edited the original several times in an attempt to understand how an electrical panel works.

If you are new to panels, or how grounds work, buy a very simple panel and examine it with a multimeter for continuity, and understand what the utility wiring involves. I found it explained most of what I needed to understand about how they work. Not about safety, but about function. Use some breakers and set them up/replace them, etc. Obviously this is done with no inputs attached to begin with.