Central AC - How long should I wait after turning on breaker?

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Jul 7, 2014
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Winnipeg MB CA
We've pretty much gone from cold to hot here. Time to use the AC.

I just turned the breaker back on. Typically they say to wait 24 hours before running the AC, to allow the oil to warm up.

Any pros here who can confirm this is required?

Thanks!
 
I don't know what kind of system I have however when its time to turn it on I set it at 74 and let it cool. No wait time required for my central A/C system which is about 10 years old. I use the Nest thermostat too.
 
We've pretty much gone from cold to hot here. Time to use the AC.

I just turned the breaker back on. Typically they say to wait 24 hours before running the AC, to allow the oil to warm up.

Any pros here who can confirm this is required?

Thanks!

That's only if:

1)It is heating season

2)You have a heat pump

3)Heat pump is equipped with a crankcase heater

Crankcase heater is only needed when the compressor is going to be called into operation when it is colder outside than it is inside (and then it has to be a significant difference).

Not the case if you're running AC.

And heatpumps with scroll compressors don't even come with crankcase heaters anymore.
 
That's only if:

1)It is heating season

2)You have a heat pump

3)Heat pump is equipped with a crankcase heater
Brian, thanks. To answer your questions:

1. No, it's no longer heating season.

2. No, it's a conventional split system.

3. I don't think this would be found on a conventional system, would it?
 
Brian, thanks. To answer your questions:

1. No, it's no longer heating season.

2. No, it's a conventional split system.

3. I don't think this would be found on a conventional system, would it?
I have no idea what this topic is about. On a conventional split system (nothing else noteworthy about it) you don't have to wait at all but you don't have any reason to turn the breaker off either. The thermostat handles that fine, whether set to heat or cool.
 
I have no idea what this topic is about. On a conventional split system (nothing else noteworthy about it) you don't have to wait at all but you don't have any reason to turn the breaker off either. The thermostat handles that fine, whether set to heat or cool.
its common to turn off the breaker for the season
24hours is standard answer for the OP IIRC.
of course many compressors have no heater. so who knows.
 
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Here in FL with central ac/heat we can use both in a single day depending on time of year, not sure how a 24hr period wait could make sense, doesn't sound reasonable imo
 
its common to turn off the breaker for the season
24hours is standard answer for the OP IIRC.
of course many compressors have no heater. so who knows.
Thanks, that confirms what I've heard previously.

As far as turning off the breaker, the cooling season here is typically only late May or later until late August. I've heard that the cost of keeping the breaker on is about $5/month. I'll gladly flip the breaker off to save $40 or more annually.

As well, the compressor can burn out if the unit is run with the winter cover on. Having the breaker off ensures no one turns the unit on accidentally.
 
its common to turn off the breaker for the season
24hours is standard answer for the OP IIRC.
of course many compressors have no heater. so who knows.
No, it's not common at all to turn off the breaker on a system where there is no need to do so. Nobody does this unless misinformed by something they saw on the internet, or it is a less than typical system setup.

FWIW, I worked in the HVAC field but years ago, couldn't tell you all the bells and whistles that are out there today.

Bottom line is, this is not some uncharted territory. Read the owners manual for your unit. If it needs the breaker off or benefits at all, the manual will state that. If it needs a pre-heat, it will state that too.
 
Thanks, that confirms what I've heard previously.

As far as turning off the breaker, the cooling season here is typically only late May or later until late August. I've heard that the cost of keeping the breaker on is about $5/month. I'll gladly flip the breaker off to save $40 or more annually.

As well, the compressor can burn out if the unit is run with the winter cover on. Having the breaker off ensures no one turns the unit on accidentally.
There should be NO power consumed by it with the breaker on if there is no call for cooling, zero savings. Even if it's some fancy unit with its own microcontroller, should only consume very low mA which is less, probably much less as a %, than $1/year.

I'd appreciate it if you could link to a source of information to the contrary?

Winter cover? There's winter here, snow, ice, etc, no cover. Does the owner's manual state it needs one? It doesn't unless you live in an unusual climate where there are episodes where it snows overnight and ices it up, but then warms up so fast the next day that it might need to run before the ice melts off.

If it is accidentally turned on in winter, it won't run because it's colder than what the thermostat is set to. I suppose there is some kind of terrorist event where someone fiddles with the thermostat, but this is a very strange kind of theory, that someone would expect that to happen.

Just saying', I don't know about you but I can't recall a time in my life that it was cold out so heat was needed, and then (if I subscribed to having a cover over it) that I had some urge to turn the AC on while it was cold outside so it was covered. If you have children that might do this, I would mount the thermostat higher on the wall and/or consider a tamper proof box over it.

Whole topic makes no sense unless vital details have been omitted.
 
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Here in FL with central ac/heat we can use both in a single day depending on time of year, not sure how a 24hr period wait could make sense, doesn't sound reasonable imo
But you wouldn't be turning off the AC breaker in-between, would you?
 
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