The automatic switch would have worked great with your 2 smaller, less thirsty A/C units. When one A/C wants to start up, the system checks to see there is enough capacity at that time. If not the A/C unit is "shed" until it can safely be started. The 2 biggest advantages of the automatic switch & standby NG/LP generator are that: 1) it doesn't require using or storing or trying to go out & get gasoline when you need to run it 2) it is automatic & my wife can benefit from it running when I'm not at home. She would never be able to drag the portable generator out & hook it up & get it started & decide what circuits to feed if I were not home. The biggest disadvantage is cost. You also need a lockout system to prevent potentially backfeeding power up the line & killing a power company worker who is trying to get your power back on. I have heard of people with home generators being criminally charged for doing this, plus the inevitable $1M lawsuit.

Thanks for all the replies! My reason for running the #6 ground is that I already have it. If I didn't, I'd go with the #8 for sure. I know that code here does not require sch80, and my only reason to run 2" was ease of pulling the #6 conductors. If memory serves, the conduit fill calculator I checked specified 1" or 1 1/4" for 4 pieces of #6 and 2 of #12. That would indeed make termination easier. Maybe pulling the #6 through 1" or 1 1/4" won't be that difficult, I do not know. I have never pulled #6 through conduit before. I have not verified as of yet, but this generator was previously installed localy (same codes apply). I have yet to install the generator itself into the enclosure and reconnect the leads from the generator head. However, I was under the understanding that the critical thing on the ground is that it is not grounded except to be connected to the ground wire that will run back to the ground bar in the breaker panel? Ditto on the neutral. Am I not understanding something correctly, or am I missing something?

Hi, I am actually quite surprised at the issues you are having with your generator. To me 57Hz to 60Hz is a small difference. To me it seems that you have something else amiss in your wiring of the generator. Computer power supplies are mostly switch mode these days and will be able to adjust to the slightly different frequency. The thing which makes me suspicious is your fan just buzzing. A fan is not like hi-tech, it is just a motor. Why would it start buzzing? It seems that you have something else out of wack here and not just a matter of frequency. If the frequncy was wrong, it would still spin be it slightly slower perhaps. Granted the current may be a little higher, but at 5% difference (57Hz to 60Hz) I think it should be fine. Does your fridge run O.K. as does your lighting? Lighting (vanilla light bulbs anyway) should be the least sensitive to differences in power frequency and up to a point voltage. I have a Cummins Onan generator and everything works just fine on it. My hunch is as follows: 1) 57Hz to 60Hz is a minor issue 2) Something else which is a bigger issue is not right here 3) My guess would be the way the Generator is hooked up to the house, or you may have a generator which is not what you think it is. What is the model of that generator? 4) When the electricians took readings, did they check readings at the computer power outlet? I am trying to reconcile that they took readings, and confirmed that everything was O.K., when you are having these issues. My hunch here is that they took readings at the generator, and those were correct. However they did not take readings at the power outlets to your computer etc. They did not do this because hooking up the house was causing all these issues and they did not want to damage anything. So they checked the readings at the generator only, without hooking it up to the house. 5) Worth getting I think a second opinion from another electrician who has experience in backup power systems. One often confused area is the switching of neutrals, and ground bonding. Backup power systems installs are sort of rare, so if this is your electrician's first time install, then he may have confused the generator hook up at the transfer switch and how the neutral should be handled and how the generator should or should not be bonded to ground. I have included a PDF link which explains the issue. It is sort of tehcnical, but it is important to get it right. Hope this helps, Warmest regards, Mike. Here is a link that might be useful: AC Power Hookup

I see this thread is a few months old, but I'll throw in what I've found researching this very question. The generator manufacturers instructions will likely list a minimum clearance around the unit for maintenance and operational purposes, but not necessarily for safety. That's why they also will mention NFPA 37 "Installation and use of Stationary Combustion Engines and Gas Turbines", which I found at my local library. A key paragraph is 4.1.4 "Engines Located Outdoors" (2006 edition). It requires engines and their weatherproof housings to be 5' from openings in walls and also to be 5' from structures having combustible walls. Building codes would normally consider pretty much any wood frame construction to be combustible, even if it has a masonry veneer. The clearance may be reduced "where the following conditions exist." If the adjacent wall of the structure has a 1 hour fire rating, and if the weatherproof enclosure has been designed to contain a fire. The wording makes me think that both exceptions must be met before you can reduce the 5' minimum clearance. Its my understanding that Generac will not make the claim that their enclosures will contain a fire. Now that being said, I've yet to see any photographs of installations, including those from Generac or their dealers that show a generator offset that far from a wall. This may simply be a standard rarely enforced, or I may be fundamentally misunderstanding its application.