# Generator+HVAC



## zulfie (Jun 14, 2021)

Hi,
Looking for some guidance please, want to get a generator to power a 5 ton AC unit and a few items like fridge, internet, some lights.

I want to add a Transfer Switch, however, the 5 ton AC's breaker is in the main panel next to the meter, which is on the outside of the house and the other circuits are in a sub panel in my garage.

Is it even possible to run the AC and the circuits to the xfer switch?

Thanks...


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## Browse Deweb (Jan 16, 2021)

zulfie said:


> Hi,
> Looking for some guidance please, want to get a generator to power a 5 ton AC unit and a few items like fridge, internet, some lights.
> 
> I want to add a Transfer Switch, however, the 5 ton AC's breaker is in the main panel next to the meter, which is on the outside of the house and the other circuits are in a sub panel in my garage.
> ...


Look at an interlock kit for your main panel. Usually the generator breaker goes in the top slot, so you may need to move some circuits further down the panel. You'll also need a soft start kit for an AC that large. Check out the MicroAir EasyStart 368. I have a 4-ton AC and my Honda EU7000is won't run it. You're going to need a large generator...probably in the 10-15kw range.


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## JJ Ranch (Apr 23, 2021)

What's your budget? You can make almost anything work with deep pockets. Generator by the utility entrance along with the transfer switch. Run the entire house on a generator.


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## ToolLover (Jan 13, 2020)

I think you will have to install a sub panel and put the breakers in it for the devices you want to power.
The process is easy, but requires a licensed electrician to do the work.


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## FlyFisher (Jun 30, 2018)

zulfie said:


> I want to add a Transfer Switch, however, the 5 ton AC's breaker is in the main panel next to the meter, which is on the outside of the house and the other circuits are in a sub panel in my garage.


If I am reading what you typed correctly - there are only 2 loads on your "main panel" (IE - "service entrance" panel). 1 - your AC, 2 - the feed to your interior "sub panel". 

Adding a transfer switch to this set up wouldn't be at all any different than a single panel - if you are doing a whole panel transfer switch**. Once you get the source (utility or generator) to the main panel everything down stream is the same circuitry as you have now. 

**There are transfer panels you can get that will isolate your key circuits and only transfer these circuits, as opposed to the whole panel. This is a totally different set up and I am assuming this is not what you are after - you are after a whole panel transfer switch.


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## zulfie (Jun 14, 2021)

Thanks for the input everyone, much appreciated. I should have clarified, the main panel not only feeds the sub panel, but the 2 ac units, pool, exterior gfci circuit and also another 60A panel that I mainly use for Christmas lights 🤣
@Browse Deweb, thanks for the info on the Easy Start, definitely something I should do regardless. 

Im here in Texas and with the ice storm and most likely rolling blackouts coming, wanted to get a generator to power the 5 ton AC unit and just a few critical circuit. 

My plan was to put the transfer switch next to the sub in the garage, add the few critical circuits (fridge, some lights) and them somehow figure out how to add the 5 ton AC unit to it. Would I have to run a line from the AC breaker on the exterior panel to the transfer switch? Definitely not trying to power the whole house. 

Thanks again, appreciate all of the input!!!


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## zulfie (Jun 14, 2021)

Browse Deweb said:


> Look at an interlock kit for your main panel. Usually the generator breaker goes in the top slot, so you may need to move some circuits further down the panel. You'll also need a soft start kit for an AC that large. Check out the MicroAir EasyStart 368. I have a 4-ton AC and my Honda EU7000is won't run it. You're going to need a large generator...probably in the 10-15kw range.


That's strange, a 4 ton even with 10 SEER should be 4kw and maybe up to 6500 on start up, shouldn't that Honda handle it? I could be missing something on the calculations.


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## Browse Deweb (Jan 16, 2021)

zulfie said:


> That's strange, a 4 ton even with 10 SEER should be 4kw and maybe up to 6500 on start up, shouldn't that Honda handle it? I could be missing something on the calculations.


It pulls 129 amps on startup (LRA) and runs at about 22 amps @ 240V. The Honda is running on natural gas, so it can only provide about 5kw continuously. Even if I had a soft starter on it, I wouldn't have any power available for other things. I don't want to run the Honda that hard during an outage.


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## JJ Ranch (Apr 23, 2021)

It really doesn't matter how many sub panels you have downstream of your utility entrance as long as you use a transfer switch *at *the utility entrance. If you don't want a generator capable of powering everything at one time you can manually switch off breakers for non-essentials. That's what I was doing when my EU7000is was the sole emergency power source, the Honda is wired into the house load center and doesn't power my garage and pump house/well.


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## iowagold (Jan 22, 2020)

zulfie said:


> Thanks for the input everyone, much appreciated. I should have clarified, the main panel not only feeds the sub panel, but the 2 ac units, pool, exterior gfci circuit and also another 60A panel that I mainly use for Christmas lights 🤣
> @Browse Deweb, thanks for the info on the Easy Start, definitely something I should do regardless.
> 
> Im here in Texas and with the ice storm and most likely rolling blackouts coming, wanted to get a generator to power the 5 ton AC unit and just a few critical circuit.
> ...


look in to portable room ac units for when you are on gen set.
way lower on the power required.
how many square feet is the house?


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## drmerdp (Apr 10, 2018)

I’m a big fan of the microaire soft starts. I have one on my 3.5 ton unit. 120LRA. No dimming lights, the the AC turns on, and it’s easier on the motor windings, potentially adding longevity To the compressor. My eu7000 can start the unit easily if I have my eu2000 paralleled with it. (Not recommended)…


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## jeb (Feb 16, 2021)

drmerdp said:


> I’m a big fan of the microaire soft starts. I have one on my 3.5 ton unit. 120LRA. No dimming lights, the the AC turns on, and it’s easier on the motor windings, potentially adding longevity To the compressor. My eu7000 can start the unit easily if I have my eu2000 paralleled with it. (Not recommended)…


Wow, how are you doing that with 240VAC? I thought the EU2000 is only a single phase. Would have thought that you'd have to have a larger inverter generator that had an L1 & L2 phase? Or are you just doing it on one phase...so you can load that side a little higher?


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## Browse Deweb (Jan 16, 2021)

jeb said:


> Wow, how are you doing that with 240VAC? I thought the EU2000 is only a single phase. Would have thought that you'd have to have a larger inverter generator that had an L1 & L2 phase? Or are you just doing it on one phase...so you can load that side a little higher?


Here's a video of a guy doing this:





The smaller generator reduces the loading on the larger generator by the looks of the displayed output.


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## iowagold (Jan 22, 2020)

yea the little gen is on the side that has the 120 volt stuff for the hvac fans.

i lock my hvac blowers to on when i am on gen set.
that helps!


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## San (Sep 22, 2021)

f


zulfie said:


> Hi,
> Looking for some guidance please, want to get a generator to power a 5 ton AC unit and a few items like fridge, internet, some lights.
> 
> I want to add a Transfer Switch, however, the 5 ton AC's breaker is in the main panel next to the meter, which is on the outside of the house and the other circuits are in a sub panel in my garage.
> ...


Instead of confusion you can through review sites.


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## Bulldogger (Feb 19, 2021)

I had decided against the expense of a manual service entrance transfer switch. But Ida made me reconsider. I could be in my current location longer AND I unexpectedly inherited a small amount of money, enough for this. I went ahead and bought an EZ Connect 200amp transfer switch. You have to get the models with the breaker to be "service entrance rated." The model I purchased is the EZC-M200, EZ-Connect with no inlet (200A) and 200A disconnect. I already had an inlet box and didn't think the way they have the plug on the side of the box is rain proof, like box I have. The switch is a large box, almost 2 feet long by about 14.5 inches wide. This is same company that makes Generlink. I purchased the switch from Home Depot but you can purchase it directly from them. Also, after looking at the wiring of my generator, it will be simple to just wire the generator it's 75amp breaker directly to the switch at a later point. Electrician is coming in the morning. Not sure when he will do it. I am guessing, since the red tag on the panel from the power company will have to be cut, that he will have to do some sort of planning and thus not do it tomorrow. This will allow me to ultimately get the full 27000 watts starting and 18000 watts running power out of my generator and power at least one of my central AC units.


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## drmerdp (Apr 10, 2018)

Bulldogger said:


> I had decided against the expense of a manual service entrance transfer switch. But Ida made me reconsider. I could be in my current location longer AND I unexpectedly inherited a small amount of money, enough for this. I went ahead and bought an EZ Connect 200amp transfer switch. You have to get the models with the breaker to be "service entrance rated." The model I purchased is the EZC-M200, EZ-Connect with no inlet (200A) and 200A disconnect. I already had an inlet box and didn't think the way they have the plug on the side of the box is rain proof, like box I have. The switch is a large box, almost 2 feet long by about 14.5 inches wide. This is same company that makes Generlink. I purchased the switch from Home Depot but you can purchase it directly from them. Also, after looking at the wiring of my generator, it will be simple to just wire the generator it's 75amp breaker directly to the switch at a later point. Electrician is coming in the morning. Not sure when he will do it. I am guessing, since the red tag on the panel from the power company will have to be cut, that he will have to do some sort of planning and thus not do it tomorrow. This will allow me to ultimately get the full 27000 watts starting and 18000 watts running power out of my generator and power at least one of my central AC units.
> View attachment 10170
> View attachment 10171


Looks good, simple and effective. So your plan is to hard wire a cord/cable from the generators 75amp breaker to the switch without a connector??


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## Bulldogger (Feb 19, 2021)

drmerdp said:


> Looks good, simple and effective. So your plan is to hard wire a cord/cable from the generators 75amp breaker to the switch without a connector??


 That was the plan. Electrician just left and shot that idea down. He didn't elaborate but strongly advised against wiring off the 75amp breaker. My house is bit on the larger size with a 4ton and 3.5 ton central air, upright freezer and separate refrigerator, washer and electric dryer, free standing ice maker, 6 wall mounted tv's, 10 ceiling fans, etc. You get the picture. He was cautious that I could easily overload the generator. He has to assume I'm stupid right? You never know what level of knowledge the client has or what their behavior will be. Also suggested I bury the cable and not use the soow cable I have because it would have been easier. I bought an soow cable because I knew I could resale it if anything changed and I expected I might not want to be locked in to 50 amps.

It's likely that I will at least add a 60 amp breaker to the generator and buy a bigger soow cable. There is some redundancy there, a cheap 75 amp Chinese made breaker followed by a cheap 60 amp breaker. At least that way the 75amp breaker is not the sole thing that is preventing the generator from overloading and catching fire. It would be different if I were using a circuit panel mounted 50 or 60 amp breaker to connect the generator. Then I'd still have two breakers preventing an overload. With the service entrance transfer panel, it's just going all into the house and the only breakers preventing the generator from overloading are the ones on it.


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## drmerdp (Apr 10, 2018)

I’d rather you don’t hardwire it either. Definitely can’t blame that electrician for airing on the side of caution. Lots of knuckleheads out there. 

I know you are eager to implement a setup that capitalizes on more of the generators capacity. But maybe it’s prudent to stick with the 50 amp connection and observe how things work out while planning for a more complete system.


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## jimshoe (Oct 2, 2021)

drmerdp said:


> I’d rather you don’t hardwire it either. Definitely can’t blame that electrician for airing on the side of caution. Lots of knuckleheads out there.
> 
> I know you are eager to implement a setup that capitalizes on more of the generators capacity. But maybe it’s prudent to stick with the 50 amp connection and observe how things work out while planning for a more complete system.


Here's a link. I just got done checking this info to verify is my gen can handle the AC.






Air conditioning and heat pump loads on a generator


Chart showing how many kw and amp an air conditioner & heat pump uses. Air conditioning and heat pump loads on a generator.



www.generatorjoe.net


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## Bulldogger (Feb 19, 2021)

drmerdp said:


> I’d rather you don’t hardwire it either. Definitely can’t blame that electrician for airing on the side of caution. Lots of knuckleheads out there.
> 
> I know you are eager to implement a setup that capitalizes on more of the generators capacity. But maybe it’s prudent to stick with the 50 amp connection and observe how things work out while planning for a more complete system.


 Those are my plans. Test first. I was never eager to get max watts out of generator. Never seemed logical to plan to run a portable generator full out. My plan to use two line for 15kW out of an 18kW running generator seems like ample power. I'm running propane. U.S carbs claims no power loss with their kits vs gasoline?


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## Bulldogger (Feb 19, 2021)

jimshoe said:


> Here's a link. I just got done checking this info to verify is my gen can handle the AC.
> 
> 
> 
> ...


 Good link. A 50 amp connection on these generators with the push button thermal breakers runs at 200% load for 60 seconds, 100 amps. That's long enough to start one of my ACs, my 4 ton.


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## iowagold (Jan 22, 2020)

hey dogger
do you have a meter setup yet for the gens?
they are a great idea to have inside by the main panel.
pm if you need details and build pix.
they are easy to setup.
if you have basic metal machine shop skills.


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## Bulldogger (Feb 19, 2021)

iowagold said:


> hey dogger
> do you have a meter setup yet for the gens?
> they are a great idea to have inside by the main panel.
> pm if you need details and build pix.
> ...


 Thanks! I will.


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## Bulldogger (Feb 19, 2021)

JJ Ranch said:


> What's your budget? You can make almost anything work with deep pockets. Generator by the utility entrance along with the transfer switch. Run the entire house on a generator.


 Yeah it's a bit expensive which is why I was reluctant. Transfer switch, $600, 50amp inlet box,$80 and labor quoted for install $800. That's for a manual switch.


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## DuncanJac (Dec 30, 2020)

Yes, it all depends on the budget. $800 for install is too much...
I think that you can find someone to connect your HVAC system for less money and less time. When I needed air conditioner installation in my house, I called the professionals because I didn't want to do a bad job myself. They didn't take long, and I paid nowhere near $800.
If you look online for cheaper options, I'm sure you'll find something. I wanted to save money too, and that's why I've spent a lot of time looking. You also need to make sure that the people you hire will do a good job because you don't want to do it again.


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## iowagold (Jan 22, 2020)

these days $120 per hour is the new norm for a good electrical guy.
all that insurance and cost of tools etc.
you get a couple of guys on a site the 800 happens fast!


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