AC Contactors Explained In 90 Seconds

AC Contactor: amzn.to/3oeKTYR
Full Video: • AC Won't Start - How T...
Quick video explaining how contactors work. Be sure to watch the full video to see how to replace yours if you have one that has failed.
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[@haipham638]

Thank you Ben!

[@GreyRockOne]

Thanks! I do all my own mechanical and electrical work, cleaning and maintenance, except refrigerant for obvious reasons.

[@tabithafranklin8750]

Dude, you are awesome! Thanks for the tutorial!

[@dido1803]

Really great information!!

[@bobrub]

Very nice Ben, I've "BEEN" watching your channel for many, many years now as you have an excellent teaching/presentation method. I have no contacter in my condenser, but a communicating "Comfortnet" circuit board, so I guess you would know that to be a Goodman system. My 2 stage 2 ton HP has worked flawlessly for 12 years now (just 1 cap replacement) and was wondering if you had much experience with that "Comfortnet" system/board and if you'd consider a future video on one and how the board works. Mine also has it's own 24v transformer for the outside system along with the Goodman/Amana communicating T-Srat . and a 2 stage 95% gas furnace indoor with only 2 data/commucitating wires out to the HP as it (HP) has it's own power transformer. I think this/my system is a 16 seer just before they developed all the inverter A/C systems out now.

[@urbanbshvac]

Great work bud 👍

[@stan525]

always good info

[@checopacheco420]

Super good stuff 🎉

[@ricardobernardo2603]

THAMKS FOR SHARING

[@TheDroppedAnchor]

Dang good tip. Thx

[@rhelouin]

If my AC calls for a 20 amp contactor, would there be any downside to using a 40 amp, other than cost ?

[@ianbelletti6241]

You missed the fact that they can, on occasion, weld themselves shut. More common, however, is the fail open issues. Because there are contactors for other purposes, you also need to double check not only that the contacts have the right amperage rating but that your contactor has a 24v coil. The wrong coil will mean that the contactor will not close when the control voltage is applied.

[@audiophileman7047]

So in reality, a contactor is just a relay (electronic switch) that starts the AC unit or does it do something more?

[@publicmail2]

yes its a 24v relay no more.

[@audiophileman7047]

@@publicmail2 Relays are usually encased, so it was strange to see one open where bugs and junk can get into it. That's really a poor design, but we know it's cheaper to use something like that when they made the unit. Thanks! 👍

[@bnasty267]

@@audiophileman7047 One advantage of the open contactor design is to allow the technician to manually depress the 'switch' to check operation of the system (as Ben did here.) Some of the dead-simple AC units don't have any low-voltage circuitry in the compressor unit (besides the contactor), so there's no source of the ~24VAC besides the thermostat. Sure, the tech could carry a battery or whatever to temporarily engage the contactor, but manually engaging the switch can allow you to isolate the high voltage side as the problem assuming everything (fan and compressor) kick on. Then you know it's a thermostat wire, thermostat, 24VAC power transformer, or contactor problem.

[@audiophileman7047]

@@bnasty267 Good points, but can't they make one that has a button you can push outside an enclosure? If I can, I will sometimes use a jumper wire to open and close the circuit for relays I'm testing.

[@bnasty267]

@@audiophileman7047 Well, you definitely probably shouldn't try to jumper wire the HV side of an AC contactor. That is usually 240V and 20A+ with more like 60-80A inrush current. I guess the design shown in the video is a compromise that mostly covers it from bugs/debris, but still allows it to be opened. Most of the units with computer boards use a traditional relay mounted to the board or the inverter systems don't use a chunk-chunk switch at all.

[@drewbush6535]

Where do you buy contactors

[@Balticblue93]

Pick your favorite HVACR company to come out and do a planned maintenance and check your contactor, capacitor, clean both coils, and check your pressures and temperatures. I suggest looking for a small one man or small business to support versus big brand names that run commercials and advertisements because you will pay more for their overhead.

[@SmokiesDen]

Zoro, grainger, automationdirect, McMaster Carr, hvacr supply houses, electrical supply houses etc…

[@BenjaminSahlstrom]

Link in description! ;)

[@AngelRamos-kn9bx]

,,👍👍👍👍

[@publicmail2]

If I have a single pole contactor say 30 amp, I'll replace with a 40 or more double pole and parallel both together, then you have an 80 amp which will last the life of unit.

[@ScottAcy]

No. Single pole contactors are designed to allow current to flow through the crankcase heater so your refrigerant won't migrate into the oil. Stick to hiring professionals is the best advise.

[@publicmail2]

@@ScottAcy That's true in some cases, it's perfect to do it you would effectively have a single pole contactor with crankcase heat intact. It has to be wired correctly.

[@Jon-hx7pe]

ewww, nest!

[@CarmeloCapiche]

Should know! Don't tell me what I need to know! Are you vaxxed and boosted up or something? Ever watched the movie They Live??