I'm told that if the breaker is left on, there is some power consumption even if the AC is not operating. I'm not an HVAC tech, so cannot confirm this.
The winter cover came with the unit - I presume the manufacturer intended that it be used.
Central AC - How long should I wait after turning on breaker?
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The winter cover came with the unit - I presume the manufacturer intended that it be used.
^ Told by who? Generally, the control board uses same power until the thermostat issues the cooling signal, then the control board energizes a relay or transistor to activate the AC, no power used by it until then.
Read the owners manuals for the furnace and AC. Efficiency ratings in HVAC have been important for a long time, they would not leave something like this on the table as waste, when it hasn't been for decades of HVAC design.
Read the owners manuals for the furnace and AC. Efficiency ratings in HVAC have been important for a long time, they would not leave something like this on the table as waste, when it hasn't been for decades of HVAC design.
Only if it had to operate in the winter, like a computer room air conditioner. Then a crankcase heater might prevent compressor failure. (Incidentally, I once worked at a place that had a regular split AC system to cool the computer room. The compressor on it failed in the middle of winter. It had no crankcase heater. I think that is why it failed...).
Who is "they"?
I've never heard of this. If temperatures even remotely permit the use of AC, the unit is warm enough.
If you have a crankcase heater then yeah, energize it and wait 24 hours. My 2 ton York AC unit however does not have one, yours likely doesn’t either. Those heaters seem to be more of a thing on larger RTU’s (rooftop units, aka package units) and stuff that needs to be cool year round (walk in freezers/coolers) and heat pumps.
I'm an HVAC tech. There is no reason to turn the breaker off during the off season. Also no reason to wait to turn the unit on if you just turned the power on. As others have mentioned its not a heat pump so it doesn't have a crank case heater.
Just run it. You may not even have a heater installed within your system. I shut off the breaker during the winter months as well. My thinking, why keep energized if it won't be used for six months. I turn on the breaker and run it when it gets hot in the spring.
Google the wiring diagram of your AC's condenser unit and see if there is a compressor crankcase heater. If you don't have a heat pump, your compressor will not have a heater. Regards
I believe it is not common as well , but may be a habit one should get into.
most new thermostats come with an automatic switch over from heating to cooling if you are one who covers your outdoor condenser you may may run into the cooling cycle coming on when an unexpected warm day pops up in the early spring.
This feature can be turned off but if you happen to forget !
The reason i mention this is a neighbour two doors down one early spring afternoon when i was out for a walk had his COVERED outdoor unit running i could actually smell the heat and hot oil smell from the side walk, so i go to the door no one is home , i went to the disconnect outside the unit and turned it off. Later in the afternoon i go back and tell him what i did and he goes on to tell me about not remembering to stop the auto switch over setting . lucky for him no apparent damage was done ! but i am sure some life was sucked out of his system ?
Gee, someone besides me reads an owner's manual. 
)
)I did for my Lennox, but nobody bothered to read it I guess (post #8).Gee, someone besides me reads an owner's manual.
what does the breaker has to do with this? Are you talking about the PAG oil in the refrigerant? How does it know the state of your breaker? This is a serious question. Who is waiting for 24 hours?
My conventional split system Lennox didn't come with a crankcase heater, and the replacement compressor I put in didn't have one either, but it is ~25 years old R-22. Even if it had a crankcase heater, it's not needed at temps above 40F or so, it's there to prevent the oil from being pumped out of the compressor with the refrigerant when it's extremely cold (which would only be on a heat pump, 99.9% of A/C won't be running in A/C mode at 40 or below).
No it's not necessary. I do it because I just don't like the idea of something being energized outside during winter that is going to just sit there unused for six straight months.
For what it's worth, I heard this years ago. I went out with my Amp clamp and measured about a 70 Watt power draw while the compressor was off. Figured that was like leaving a 70 Watt light bulb on 24/7 from November until April. So I started turning off the condenser breaker when I knew there would be no more need for AC until spring. I cover the unit up too, to keep pecan tree and crepe myrtle leaves from falling through the top and turning to mulch in the bottom of the unit. When spring comes and I know I will be needing AC I turn it back on and put the cover away. It is a 3 ton R22 Goodman unit on it's 25 season. Still cools great.
I just checked the current draw with the breaker on and the thermostat off (not calling for cooling). There was no measurable current.
The clamp-on (which only goes down to 2 A) didn't register, so I disconnected the BK conductor and put a conventional meter in series - again, nothing, even on the 200 mA range.
Then I read the installation instructions that came with the AC system - a Lennox 13ACD-series unit. They say that IF the unit is equipped with a crankcase heater, it should be energized (i.e. breaker turned on) for 24 hours prior to start-up.
Given that there was no current measured, I presume the unit is not equipped with a crankcase heater - and therefore that I'm not saving any power by turning the breaker off for the winter.
But I suppose it's possible that there is a heater which is thermostatically controlled, and that it was drawing current earlier. I should have measured it yesterday when I first turned on the breaker.
But in any case, it's been just over 24 hours, so it should be good to go regardless.
Thanks, all, for the input.
The clamp-on (which only goes down to 2 A) didn't register, so I disconnected the BK conductor and put a conventional meter in series - again, nothing, even on the 200 mA range.
Then I read the installation instructions that came with the AC system - a Lennox 13ACD-series unit. They say that IF the unit is equipped with a crankcase heater, it should be energized (i.e. breaker turned on) for 24 hours prior to start-up.
Given that there was no current measured, I presume the unit is not equipped with a crankcase heater - and therefore that I'm not saving any power by turning the breaker off for the winter.
But I suppose it's possible that there is a heater which is thermostatically controlled, and that it was drawing current earlier. I should have measured it yesterday when I first turned on the breaker.
But in any case, it's been just over 24 hours, so it should be good to go regardless.
Thanks, all, for the input.
Did you ever rip out that small fuse box and install breakers?
My Amp-clamp will measure lower than that. It was measuring around .6 of an Amp. X 118 V on that side of the 236 VAC going into it, that's how I came up with 70 Watts. Pretty sure I did it when it was cold outside so it might have an internal thermal switch. I have not checked it when ambient temps were warm. It's also a lot older probably than yours. 1997. Anyway looks like you found your answer!
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