PTO generator at max torque or max HP?

[mini14]

I have 2 gennys, i hate to waste resources so i operate them load dependently one is a 5500 watt gas honda the other is a 1600 watt inverter chinese made throwaway that runs great. the inverter genny will run 8-10 hrs on 1 gal. just a few lights and power the fridge all day/night long, i rarely use the 5500 watt one to power the whole house minus the ac. it just eats too much fuel. i have many customers with 25kw whole house gennys that run all day/night long when know body is home. ideally i would get an 1800rpm 4 pole genny but they are crazy expensive

 

[5030]

Interesting thread. With my diesel standby, neither horsepower or torque really matters. What matters is the rpm the engine is turning the armature at, which in my case is 1800 rpm.

 

[workinonit]

Maybe not but what does "matter" is load, specifically, sizing the generator for your specific load. And even more specific is to make sure you have enough head room above normal loads to start any inductive loads you may be driving. Second is frequency. As you stated, the gen needs to run at rated speed or bad things happen. If those things are squared away, voltage should not be an issue.

 

[5030]

Usually the genny's engine is sized for maximum output amperage. As the load increases, the physical resistance to the rotating armature increases and the engine works harder to maintain the correct rpm. Most all of them can surpass rated output for a short time as in starting a large electric motor. I know when my screw compressor starts and the genny is running, I can hear it grunt for a second, when the inrush amperage is high. Same with the Quincy reciprocating compressor. Both have 8 horse capacitor start, induction run motors. In rush is about 3 times running amperage.

With an inverter it don't matter so long as the electronic frequency generation is capable of providing the correct amperage and frequency.

Most inverter genny's have multiple pole heads, as many as 9 or 10. I guess the cost of them (Inverters) kind of limit them for heavy use as every one I've seen are about 2500 watts or less. Never saw a 3 phase one either. All single phase.

Never got into the mechanics of either of them, inverter or conventional, so long as they work, I'm good with that.

 

[Sawyer Rob]

Honda makes/sells some bigger inverter generators...

SR

 

[Smokeydog]

Years ago I got a small digital led plug in volt meter. Keep plugged in over the coffee pot in the kitchen. Use to watch the voltage change from 108 to 118 @0600 on cold mornings. Lights brighten and refrigerator hum changed. Now have 3phase at the road and underground 1/2 mile at the house. Steady 121-122V. Significant decrease in power outages at first but now becoming more frequent I think from the tremendous building boom.

What is a good hertz gauge to monitor utility and generator power? I see one brand of pto generator that has AVR option. Is that better? Cleaner power? Over a Winco?

In running a mower with a newer diesel tractors and watching the rpm I can’t tell if the engine is governed. Hold a rpm with varying load. One does have auto throttle option. The older and gas tractors I could easily tell. The newer ones might too? Don’t operate stationary equipment any more.

 

[Sawyer Rob]

I'd bet there isn't a tractor made today, that doesn't have a governor.

In fact, I've never owned a tractor of ANY age that didn't have a governor!

SR

 

[California]

An aspect I haven't seen covered in this thread: That tractor was capable of its rated PTO output when it was new - 35 years ago in the 1980's. To expect that performance now it will as a minimum need the cooling system brought up to spec, ie radiator boiled and rodded. Also I would replace all the hoses. Lets assume the water pump is as good as new. And I would do a major 1,000 hour service - Torque the head, adjust the valves, drop the pan and clean the oil pickup etc. - before expecting that elderly tractor to withstand running at its rated hp, continuous.

And I would add the low oil / overheating shutdowns mentioned above.

I hope its not a hydrostatic PTO.

 

[5030]

An aspect I haven't seen covered in this thread: That tractor was capable of its rated PTO output when it was new - 35 years ago in the 1980's. To expect that performance now it will as a minimum need the cooling system brought up to spec, ie radiator boiled and rodded. Also I would replace all the hoses. Lets assume the water pump is as good as new. And I would do a major 1,000 hour service - Torque the head, adjust the valves, drop the pan and clean the oil pickup etc. - before expecting that elderly tractor to withstand running at its rated hp, continuous.

And I would add the low oil / overheating shutdowns mentioned above.

I hope its not a hydrostatic PTO.

Interesting comment. Just had my open station M9000 at the dealer for it's scheduled overhead adjustment and injector spray / pop test and when the tech got done he put it on the PTO dyno and it's making a shy bit over 10 horses more than what Kubota rates it at. I asked him about that and he said no 2 tractors in the same model / engine range will dyno the same. It has just a tad over 6000 meter hours on it. Excellent oil pressure, starts right up, no smoke unless I'm working it hard. I've always taken good care of it just like all my tractors. I expect it to go at least 10,000 hours with nothing needing rebuilt. It's a 2002 btw.

One of my farmer buddies has a 4020 JD Diesel and he's rolled over the hour meter on it. I don't believe he's done anything major to it either, just normal maintenance.

 

[5030]

Honda makes/sells some bigger inverter generators...

SR

Was not aware of that but then I'm not in the market for ANY new generator.