L1 and L2!!

[eye in the sky]

Until recently I was led to believe that in refrigerator circuits both legs of AC power were feeding into the circuit...but, I read that one leg, typically labeled as L1 will feed power into the circuit for mainly the switch sides of the circuit, and L2 (neutral) carries the current back out of the circuit or away from the component (motor, switch, etc.) Can someone please confirm which is true?

The reason this confuses me is in this schematic.

http://imageshack.us/photo/my-images...ngbq0.jpg/sr=1

which side of power is neutral and which one is hot?

also, i need a better understanding of how capacitors work. the common terminal is for power in, but in what specifications would a jumper be used to go back out of the common terminal?

[Tiger93rsl]

Your common on the compressor is going to be your line voltage. The capacitor causes voltage to lead the current, throwing the voltage and current out of phase. This phase shift is what allows the motor to start turning. I don't understand what your asking about a jumper on the common. You don't want to add any jumpers to this circuit.

[timebuilder]

The word "circuit" is derived from the Latin, meaning "circle." L1 or L2, "hot" or "neutral" are merely words.

Your typical outlet uses BOTH main connections, the slots, to power a device. The same current is moving through BOTH wires. On a 208 - 230 volt circuit used to power a condensing unit, same thing applies.

A capacitor is placed in series with a motor start winding to create a change in the phase relationship between voltage and current. This provides an advantage of torque to start the motor rotating. If the cap is not removed from the circuit after the motor starts, we call it a run cap. If it gets removed, its a start cap. The caps themselves are designed slightly differently, but their job is the same.

Does that help?

[eye in the sky]

thanks for the replies

[eye in the sky]

Your common on the compressor is going to be your line voltage. The capacitor causes voltage to lead the current, throwing the voltage and current out of phase. This phase shift is what allows the motor to start turning. I don't understand what your asking about a jumper on the common. You don't want to add any jumpers to this circuit.

So what is the function of the run winding? Is it used to lead out voltage, as I've been told, or lead voltage in for the motor?

I suppose I'm wondering about capacitor design. For instance, in a run capacitor there is power going into common, then a jumper coming out of common (and a jumper from 'fan') for the fan motor. So in other words, the common terminal can be used for power in or out, right?

[eye in the sky]

The word "circuit" is derived from the Latin, meaning "circle." L1 or L2, "hot" or "neutral" are merely words.

Your typical outlet uses BOTH main connections, the slots, to power a device. The same current is moving through BOTH wires. On a 208 - 230 volt circuit used to power a condensing unit, same thing applies.

A capacitor is placed in series with a motor start winding to create a change in the phase relationship between voltage and current. This provides an advantage of torque to start the motor rotating. If the cap is not removed from the circuit after the motor starts, we call it a run cap. If it gets removed, its a start cap. The caps themselves are designed slightly differently, but their job is the same.

Does that help?

The start capacitor is wired through the common of the run capacitor, then feeds to the relay, then the start winding and relay are connected through the hermetic terminal of the run capacitor? Then counter EMF backfeeds to open 'normally-closed' to throw out the start capacitor. In this cirumstance, however, isn't voltage still going into the start winding?

Could you please explain 'phase'.

I really appreciate y'alls help!

[timebuilder]

So what is the function of the run winding? Is it used to lead out voltage, as I've been told, or lead voltage in for the motor?

I suppose I'm wondering about capacitor design. For instance, in a run capacitor there is power going into common, then a jumper coming out of common (and a jumper from 'fan') for the fan motor. So in other words, the common terminal can be used for power in or out, right?

I'm not sure what you have been told, but throw away any ideas about one side of a circuit having one function or another, versus the other side off the circuit.

The ENTIRE circuit has current movement when energized, and the ENTIRE circuit loses current movement when de-energized.

[timebuilder]

The start capacitor is wired through the common of the run capacitor, then feeds to the relay, then the start winding and relay are connected through the hermetic terminal of the run capacitor? Then counter EMF backfeeds to open 'normally-closed' to throw out the start capacitor. In this cirumstance, however, isn't voltage still going into the start winding?

Could you please explain 'phase'.

I really appreciate y'alls help!

If you want help with a particular circuit, then post a copy in the post where you are asking the question.

You seem to be focused on connections, and not the concepts. When you understand the concept of what a circuit is supposed to do, then the method of circuit design will begin to make more sense.

[eye in the sky]

[QUOTE=timebuilder;11819692]I'm not sure what you have been told, but throw away any ideas about one side of a circuit having one function or another, versus the other side off the circuit.

The ENTIRE circuit has current movement when energized, and the ENTIRE circuit loses current movement when de-energized.[/QUOTE

I'm not sure either why circuit voltage was described in the way I mentioned, but in this video this dude specifically clarifies the wrong thing...thank you for clearing it up.

http://www.youtube.com/watch?v=4vPYHW26RlQ

[eye in the sky]

If you want help with a particular circuit, then post a copy in the post where you are asking the question.

You seem to be focused on connections, and not the concepts. When you understand the concept of what a circuit is supposed to do, then the method of circuit design will begin to make more sense.

In reality, I understand the function of the circuits and a capacitors purpose, but needed reassurance on my understanding of how the components were wired together.

[timebuilder]

I can't watch youtube on my "dumb phone" because youtube is coded using Flash, but I will check it when I get home tonight. I have to wire a store today for EMS control.

That said, I would caution all new techs about what they find on the net as being reliable information. You guys (or gals) should be getting Pro membership status as soon as you can, so you can 1) gain access to the educational forums and 2) ask technical questions in the Pro Residential or Commercial forums.

[eye in the sky]

I can't watch youtube on my "dumb phone" because youtube is coded using Flash, but I will check it when I get home tonight. I have to wire a store today for EMS control.

That said, I would caution all new techs about what they find on the net as being reliable information. You guys (or gals) should be getting Pro membership status as soon as you can, so you can 1) gain access to the educational forums and 2) ask technical questions in the Pro Residential or Commercial forums.

thanks for the info. and i will do that. from your pro. opinion, does what i said in post 6 sound accurate?

[timebuilder]

I'll have to check it tonight.

[jpsmith1cm]

This was getting pretty tech heavy for the AOP Forums.

I moved it over to Tech to Tech as the OP seems to be a tech.

[timebuilder]

This was getting pretty tech heavy for the AOP Forums.

I moved it over to Tech to Tech as the OP seems to be a tech.

Good idea.

[timebuilder]

I'll have to check it tonight.

Okay. Here's what you posted in #6:

The start capacitor is wired through the common of the run capacitor, then feeds to the relay, then the start winding and relay are connected through the hermetic terminal of the run capacitor? Then counter EMF backfeeds to open 'normally-closed' to throw out the start capacitor. In this cirumstance, however, isn't voltage still going into the start winding?

Voltage is ALWAYS going to the start winding.

The run cap is always in series with the start winding, and the potential relay places the start cap in parallel with the run cap to increase starting torque.

Phase is the word used to describe the difference in the voltage and the current components of an AC waveform. The capacitors are being used to create an artificial "second" phase, by causing a lag in voltage waveform in the Start winding when compared to the unaltered waveform in the Run winding, helping the rotor to turn against its own inertia and any vapor load in the compressor during startup.

[snewman24]

This was getting pretty tech heavy for the AOP Forums.

I moved it over to Tech to Tech as the OP seems to be a tech.

Thanks for moving the thread JP, it was extremely frustrating reading a "basic fundamentals" thread and not being able to respond because I'm not an "asterisk".

[snewman24]

Eye in the sky...I can relate to your questions and confusion because I, too, was confused years ago about some of the terminology, and understanding how a motor circuit works. Don't get hung up on which line connection, L1 or L2, is power in. They both are, but they alternate back and forth 120 times a second. When L1 is "power in", L2 is "power out", and a 120th of a second later, they swap and L1 is "power out" and L2 is now "power in". Like Timebuilder said, "a circuit is a circle" that must be completed. We don't normally show the full circuit because we would have to show the power company's secondary transformer winding out at the pole which is part of the circuit. But electrons come out of the transformer, thru our circuit and back out to the transformer to complete the circle.

So...did your questions in post #1 get answered by Timebuilder in post #3?

[eye in the sky]

Eye in the sky...I can relate to your questions and confusion because I, too, was confused years ago about some of the terminology, and understanding how a motor circuit works. Don't get hung up on which line connection, L1 or L2, is power in. They both are, but they alternate back and forth 120 times a second. When L1 is "power in", L2 is "power out", and a 120th of a second later, they swap and L1 is "power out" and L2 is now "power in". Like Timebuilder said, "a circuit is a circle" that must be completed. We don't normally show the full circuit because we would have to show the power company's secondary transformer winding out at the pole which is part of the circuit. But electrons come out of the transformer, thru our circuit and back out to the transformer to complete the circle.

So...did your questions in post #1 get answered by Timebuilder in post #3?

Yeah, they are answered. thanks alot

[timebuilder]

Yeah, they are answered. thanks alot

Cool.

You are four posts away from applying for Pro membership.