Automating a home generator

drvnbysound

Senior Member
Has anyone done this? To be more specific, say I have a generator which can be controlled (turned on/off) via electric start. I believe I could use the Elk to determine when power has failed (e.g. power removed from the transformer) and should be able to trigger the generator to auto-start after X amount of time of the power being out. That said, before the generator is turned on, I'd actually need to turn off the home's main breaker as to not back-feed the power lines (and obviously endanger anyone working on the line), and possibly other non-critical breakers of the home as to not overload the generator with appliances or devices that are not essential during an outage. Are there any controllable breakers, which could be operated to do this automatically?
 
I understand that there are obviously other ways to do this, such as having electric motors physically switch the breaker, but I was curious to find out if anyone else has done this and if so, how?
 
 
 
For safety reasons I would have a professional electrician install a automatic power transfer switch which can be wired to automatically start your generator. Assuming of course your generator is not a portable gasoline powered unit.
 
Generators that are designed as standby power for homes or commercial applications include mechanical transfer switches that prevent backfeeding to the utility.  For isolated or unattended locations this is generally the only option. 
 
If you are intending to install your system on your home and you or someone else will be around to manually flip a switch or two you can accomplish is easily. 
 
In my opinion the problem with automatic generators is that once they start they run until they either run out of fuel, the power returns or you shut them down.  Whole house standby generators suck a LOT of fuel, regardless of the load.
 
Myself I installed a separate emergency panel which has all the circuits I want active when I'm on generator power.  This emergency sub-panel has a special set of double pole breakers with a metal cam mechanism which prevents both 2P breakers from being on simultaneously. It's kind of like having two main circuit breakers, but only one can be one at a time.   During a power outage I flip the 2P breaker fed from my generator ON, which via the cam, turns OFF the regular power 2P breaker.  I hope this is not too convoluted of an explanation.  In my main main house panel there is a 2P 60 amp breaker which feeds the "normal" 2P breaker in the emergency panel.  The other 2P breaker is fed from my generator.  I'm retiired and so as a general rule someone is around when the power goes off.  This isn't automatic by any means, but it is SAFE and FOOLPROOF. 
 
Here's a reasonably priced subpanel with interlocked breakers rated at 60 amps.  http://www.lowes.com/pd_28277-296-QO48M60DSGP_0__?productId=3128391&cm_mmc=SCE_PLA-_-Electrical-_-LoadCentersBreakers-_-3128391+&"cagpspn=pla"
 
That panel would be more than adequate for a 6500 watt generator.  If you have a 10kw or bigger, you need to look at something with a higher rating.
 
Thanks for the replies... this wasn't necessarily for me (at least not right now). I had a friend who asked me about it - I figured I would find the best answers here. I think the service transfer switch is what I was looking for..
 
That said, I'm 99% sure the generator has been converted from gasoline to natural gas. So, as long as the supply doesn't run out it would continue to run as it's connected to a service line. The idea, similar to that of many enterprise buildings, was to not necessarily have a loss of power (assuming things are also on UPS)... where if power simply flickered the UPS would handle those issues, but if power were to go out for say, longer than 30 seconds or a minute, the generator could be set to automatically turn on. Before doing the ladder, the main breaker (or service transfer switch) would need to be operated as to not back feed the lines.
 
The idea was to have this automated... The person who asked me about this has business class server equipment (both servers and routers) which he would like to continue to be up and running (obviously network connection depends on the ISP, but there are local devices that use these machines as well), along with some other standard appliances (e.g. refrigerator) so things don't go bad if power were to be out for an extended length of time... Automated because it's possible for power outages to occur when no one is home... However, doing this properly and safely is obviously of concern as well, but I think the transfer switch is the answer I was looking for. 
 
You also need to put some thought into starting the genset.
 
How long do you crank it for?
How do you know it has started?
How many times do you attempt to start it?
Should you monitor the battery (wont start without it)?
 
I automated a large 1000kVa Generator a few years ago and these are just some of the simple things that had to be dealt with.  Fortunately there was a "black box" that handled most of it.
 
Mick
 
All of the ideas/thoughts/concepts mentioned here are already covered by a home standby generator and accompanying auto transfer switch. That includes automatic switching, isolating critical circuits so that only necessary circuits are powered when on genset power, etc. They also put out "cleaner" power (important for almost all appliances/electronics), do monitoring, do load shedding (to keep to many power consumers from overloading and shutting down the genset) and weekly exercise (numerous benefits). They aren't cheap, but they aren't as expensive (or, IMO as failure prone) as they were ten years ago. You can even get them as small as 8kW.
 
Disclaimer: I have had a 22kW standby genset for about five years. Since then, I've had POCO outages of a few minutes to four days. Thirty seconds after the outage starts, I've got full power via the genset. I can't say a standby genset is a necessity, but it is really, really nice to have when you need it.
 
You can probably do it but it is far from simple.  I put in a whole house generator last year and put my old manual generator up for sale.  You have to add to the list to include such things as warm up time before switching in the load, cool down time before shutting down, monitoring when utility power comes back on, waiting to make sure it is going to stay on, transferring the load back to the utility, handling very brief dropouts, frequency control, voltage control due to load variations.  Modern whole house generators also monitor for a wide variety of fault conditions(my includes 20 possible fault conditions).  It communicates to a wireless status console in my house to notify me of a fault and provides a display of what the fault is.
 
I should have added that I use my ELK/ISY controller setup to notify me when the generator turns on and when it shuts off.  I also monitors the fault indicator to tell me a fault has occurred.
 
The APC Universal Transfer Switch might be worth looking at, their higher end unit is around $500 bucks and is capable of controlling two different 'inputs'.  Very slick system.
 
...v
 
I've looked at the APC UTS last year when I was considering a Honda generator. My local Honda Power Tools dealer sold them and if you look on their website, they have some type of partnership with APC to re-sell this transfer switch. There were two issues with it that I did not like:
 
1) The APC UTS itself needs power to be able to switch over to backup source. If you lose utility and don't have a battery backup connected to the UTS itself, it becomes essentially becomes a manual transfer switch at that point.
 
2) With a manual generator like a Honda, you still need to go outside and start the generator. The APC UTS will monitor backup source and switch your circuits over to it only when it sees the generator is running (assuming utility is still dead). Honda did sell an automatic starter for one of their EU series generators at one point but I haven't been able to find much info on it and my Honda rep seemed to think it was discontinued.
 
I ultimately went with a Kohler whole house generator with their own automatic transfer switch. While we have not yet had a real power outage to test it, I have done several failover tests for friends and family and my whole house is back on within 10 seconds of losing power. Pretty slick.
 
You would be best off going with a generator and compatible automatic transfer switch. This covers you on building codes and insurance. Some sort of transfer switch, manual or auto transfer, is mandatory so that backfeeding is never a possibility. The newer transfer switches have load shed, increasing capability. Check out Generators Direct. A 20kw Briggs with auto transfer switch costs about $4,200 and a 10kw about $3,200.
 
For further control, an Elk Relay could be easily wired up to the manual start / stop switch on the generator it's self.  We have a 16kw Briggs with auto transfer using natural gas. I have considered this upgrade to control prolonged running if we are not home during a power failure. The natural gas costs about $30 per day for the generator to run powering the alarm and security DVR. I'll pay it and keep an eye on the place with my phone.
 
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