HVAC common wires

[skip4309wtf]

I prefer to relate to Common as one side of line. Just as Run would be the other side of line in a single phase circuit for a compressor. Unlike a dual run cap which has C, F and H terminals and C would be common for F and H but wired on the Run side of line. Just like if I describe a Hot and Neutral you know I would be referring to a 115-120v circuit.

[cubarico20]

can you please show me the difference between a 1 phase compressor and a 3 phase compressor and how to check the windings and terminals in both of them the overall in the residential units thank your for all your vids they are very great and specially helpful once again thanks

[DrZarkloff]

@cubarico20 I do have a couple of videos where I show how to check the compressor windings.

[13hussmeister]

Me too!!! Thanks! Can you do a video explaining thermostat and various "control" surfaces discussing system lag and system overshoot? Thanks in advance!

D

[apnaconstruction]

Dr Z Thanks For U r Videos

Please Please Can u make Video like Storage R22 or 410 or any Freon

About Temperature and stuff like That (how to KEEP NICE way so next Summer We Can Use)

am Sorry am in NEW in HVAC/R Help us out Please ...like the way u does>>

Thanks in Advance

[GearOfWarSniper]

@apnaconstruction hello i may not be the doc but i am taking hvacr in school i am in my senior year but i would reccomend keeping it in room tempurature not to cold or to warm i think if you were to put it in a heated warehouse or home etc you should be ok and good to go for next year

[myhero70]

Some of us try to make it harder than it is Doc. Thanks for keeping it simple and thanks for your videos. I understood exactly what you were saying.

[DrZarkloff]

@myhero70 Thanks for watching.

[HVACRSupply]

In terms of hot,neutral,ground, the neutral is classed as the common. In regards to a switch which has a NO, NC, C. This is classed as a C form switch. It has a common terminal, a normally open terminal and a normally closed terminal. Depending on the position of the switch handle the circuit can be either open or closed.

[seabass3211]

Thanks for your vids. I'm in school know and I watch everyday to learn more. So thanks and keep it up.......

[DrZarkloff]

@seabass3211 Thanks for watching.

[hvacpro1]

yeah, im still a little thrown off too.. So Pri and com on the low voltage side are both sending out 24 volts to the board? Or is one a ground? Also C on the low voltage terminal strip on board is only labled so due to yellow passing 24 through it to condensor right?

[DrZarkloff]

@hvacpro1 Generally, the common (C) wire is grounded to the cabinet.

[co2x3]

Good Basic review, lov it. Dr Z an the reviewetts . be nice to do a part two from the 24 volt trans via the air handler to the ac condenser only to have a short some where?

[DrZarkloff]

@co2x3 Thanks. I'll get to it sooner or later.

[fyescas777]

Very useful information. Thanks. Some transformers don't have wires, they only have spade terminals and some don't even have the sticker showing the designations. Can you chose either one as your common side? Does polarity matters?

[corndawgz88]

@fyescas777 If it is a single phase step down x-former then the primary side doesn't matter which wire goes to which terminal(assuming there are only 2 terminals). determine which secondary side terminal is hot and common by checking voltage between each and a good ground. the side which measures voltage will be hot and the other common. polarity doesn't matter.

[DrZarkloff]

@fyescas777 Control transformers without the wiring information are practically worthless. The common on the primary side does matter. The common on the secondary side does not.

[V8Jagnut]

cool is all i can say at this time of night.lol

[DrZarkloff]

@V8Jagnut Thanks.

[Metalcastr]

So common is Neutral? or Hot? In different devices it seems to be different.

[DrZarkloff]

@Metalcastr Yes, it's usually neutral. It's typically the wire that is hot all the time.

[onecullen]

@DrZarkloff Doc, I'm confused with this answer.Can you clarify?

[DrZarkloff]

@onecullen The common wire can be the neutral wire for 120 and 277 volt systems. The common wire will be one of the live wires it the voltage is 208/230 and 480.

[IndieBraah]

Great video Doc ! You think you can do one on troubleshooting short to grounds for electrical failure?

[DrZarkloff]

@IndieBraah I plan to do one soon.

[Beantown82]

Great job as usual!

[DrZarkloff]

@Beantown82 Thanks

[1986pistolpete]

can you do some heat issues,like how to check heat exchanger or checking draft..thanks very helpful videos

[DrZarkloff]

@1986pistolpete I rarely service gas furnaces.

[myrsve]

good video DR.Z

[DrZarkloff]

@myrsve Thanks for watching.

[DrZarkloff]

@myrsve Thanks for watching.