Generator PTO generator attachment to the Home.

[mjw]

If you really need a larger amperage connector you could always use Camlock connectors.
These are what is used on TV production trucks and such.
Great if you want to upgrade to 3 phase also.

The only good picture I can find is from a dealer on Ebay, so I will not post a link.
The connectors were in the $20 each range at this store (No affiliation, I have never bought these things, just used them)

What you end up with is a single color coded cable/connector for each leg (3 for 240 single phase).

If you decide to go with these and may ever rent a generator I suggest having a set of cables with bare ends on them as many generators just have screw down terminals.

Oh yeah you could just skip all this connector stuff and go to screw down terminals if it you want.

Just a thought for anyone trying to move lots of electrons.

Matt Wehland

 

[Chuck-KY]

Most generators are rated surge/continuos duty, 15/12 or so forth. I have a 15kw pto generator myself. It is rated 15kw(62 amps@240 volts) surge, but only 12kw(50 amps@240 volt) continuos duty, thus the 50 amp 4 wire receptacle. Make sure of your continuos duty rating of your 15kw generator is before you modify the manufacturer's user connection. Most 15kw generators are only rated for 12kw and a power factor of one for continuos duty

 

[ampsucker]

i think with most high quality generators, you'll find they are rated conservatively and may actually put out MORE than they claim. whereas, cheaper models are the opposite.

we just bought a new yamaha 4.5 kw continuous model rated for 37.5 amps continuous at 120 volts and 18.6 amps continuous into 240 volts. after break-in, i plugged as many resistive loads (heaters and lights) into the 120 volt receptacles to see what it would take to pop the NFBs (non fuse breakers) built into the generator output plate. i calculated i was running about 39 amps continuous for about 30 minutes and the engine didn't even sputter and none of the breakers opened. in fact, my extensions cords started to warm up to the touch, but the generator was able to put out more than what it said it could. this was running on propane, too, which can decrease the output up to 10% or so over gas.

the NFBs on the yamaha are rated for 18 amps each but obviously have some overhead built in. i suspect they are actually 20 amp breakers, but they actually say 18 amp on the faceplate. i thought that was odd as 18 is not a common size.

another thing about generator operation, especially off tractor pto, is the concept of balancing your loads on each leg and voltage control/rpm control of the tractor. a lot depends on the generator electronics.

you will need to carefully balance each leg to get the max power. it soulds like you have a meter built in to your system. we have done the same and that helps. then, you will want to consider shedding your delicate electronic loads or certain heavy loads as prevously posted depending on how well the tractor governor can maintain the generator speed under various loads and how much sine wave smoothing the generator can do with it's onboard electronics.

lastly, always remember to fuse the conductor, not the load. meaning, the size of the CABLE (existing or new ones you add when you install your transfer switches) determines the breaker size you need - NOT the size of the generator and NOT the size of the load. the generator should have it's own protection built in and individual circuits in the home should have their own protection. the ratings for load panels and transfer switches must be at least as large as the loads they carry, but you can size up as well as size up your cables to get lower voltage drop and make sure you can utilize every watt of power your generator can produce.

hope that helps and good luck!

amp

 

[Tom_Veatch]

THe manual transfer switch must match the amp rating of your service because it has to (potentially) handle that load as supplied from the grid. You may want a 100 amp transfer, but if you have a 200 amp service, you will get a 200 amp transfer switch to meet code.

Doesn't that depend on how the transfer switch is wired in? If the service feed is into the transfer switch, I'll agree since it's effectively taking the place of the main breaker. But, if you use the transfer switch to feed a subpanel and the connection to the main panel is through a breaker in the main panel, wouldn't the minimum size of the transfer switch be determined by the breaker in the main panel?

Example: A 60 amp breaker in the main panel feeding the transfer switch from the service side, the aux. generator feeding the transfer switch from the generator side, output from the transfer switch feeding a 60 amp subpanel that contains the circuits you want powered by the aux. generator. Under that scenario, wouldn't a 60 amp transfer switch meet the requirements?

EDIT: Sorry, just read the post you were responding to. Agree, if he's going to feed a 200 amp panel through the transfer switch direct from the service entrance, he'll need a 200 amp switch.

 

[JackMentink]

Actually what I was planning on doing was feeding the panel on the load side of the main breaker and making sure the power from the utility was shut off (shut off the 200 amp main breaker when i am using the generator). This would allow me to feed to the panel through a separate 60 amp breaker and appropriate sized 60 amp wire from the generator. Would not really need a transfer switch this way.

Just have to make sure generator was disconnected (or 60 AMP breaker was shut off prior to turning the utility power on or making sure the main 200 amp breaker was shut off before the generator was connected. Not totally fail safe butr if these simple rules were followed I believe it would work.

 

[RonMar]

Actually what I was planning on doing was feeding the panel on the load side of the main breaker and making sure the power from the utility was shut off (shut off the 200 amp main breaker when i am using the generator). This would allow me to feed to the panel through a separate 60 amp breaker and appropriate sized 60 amp wire from the generator. Would not really need a transfer switch this way.

Just have to make sure generator was disconnected (or 60 AMP breaker was shut off prior to turning the utility power on or making sure the main 200 amp breaker was shut off before the generator was connected. Not totally fail safe butr if these simple rules were followed I believe it would work.

That is what an interlocked panel does, with the addition of a sliding lock plate that will only allow one of the two breakers(main or generator backfeed) to be on at a time. In order to be legal, you need that sliding lock plate... You can get a lock plate kit for most panels that meet this safety requirement. The lock plate kit is about the most cost effective way of putting in a "legal" manual transfer switch that I have come across...

 

[ampsucker]

i agree with ron on this. you need an interlock. it is just too easy for someone to forget to shut off the main line feed or to accidentally turn it back on. you need a positive way to isolate the utility from the generator that can't be defeated without some serious effort.

linemen get killed and injured every year due to systems like what you are proposing despite the homeowner's best intentions.

i know it's tempting to do it this way, but it's not your life you are gambling with. it's somebody else's. then it's your financial future when they figure out what happened and you get charged with the code violation. or, imagine your utility company refusing to hook you back up. just not worth it IMHO.

google transfer switch interlock for some good options. i bought a reliance transfer switch from notherntool that can take a 60 amp generator feed and 100 amp line feed. costs about 150 bucks. and, you can change out the breakers. they just use cutler hammer type ch3 dipoles. i modified mine to take an 80 amp input and used number 4 thhn copper wire to make the short run from the utility pole to the well house. the whole thing feeds a sub panel in the house. and a small subpanel in the well house (18 bucks plus breakers at lowes) will feed the well and a few yard circuits so i'll have light in the generator shed and can charge the generator battery with top charger. i have about 100 bucks in cable and maybe another 300 in breakers and boxes but it is a good setup and safe.


amp

 

[SPYDERLK]

Actually what I was planning on doing was feeding the panel on the load side of the main breaker and making sure the power from the utility was shut off (shut off the 200 amp main breaker when i am using the generator). This would allow me to feed to the panel through a separate 60 amp breaker and appropriate sized 60 amp wire from the generator. Would not really need a transfer switch this way.

Just have to make sure generator was disconnected (or 60 AMP breaker was shut off prior to turning the utility power on or making sure the main 200 amp breaker was shut off before the generator was connected. Not totally fail safe butr if these simple rules were followed I believe it would work.

OK. Now im with you. I do the same thru an idle 50A breaker on my house panel that I keep brightly taped to offwhen not used. My experience with 50A 220 breakers is that they will sustain 70A load for at least 30 seconds before tripping. I dont think your steady state load conditions will exceed 50A normally and im sure the breaker would hold 62A for a couple minutes if the occasion arose. I would try your installation straight off the 50A output plug. Get your house running near its max draw and monitor the plug for heat. The whole generator will get warm over time, so you want to check the plug as soon as you start, and for about 5 minutes before the gen heat camouflages the effect. If the plug warms more than a few degrees under full load I would worry. That would suggest a need to clean the contacts, or ultimately hardwire if cleaning didnt do it.
larry

 

[trubl]

Ok here is what you do. Hook up the generator to your switch. If the breaker on the generator is only 50 amps, all you have to do is dont turn on all the stuf in your house. Like you said the generator has a meter on it and you can turn stuff on until you get close to 50 amps.
Some folks are just making this harder than it should be.