Powermate 5000 generator questions

[i6pwr]

I have a Coleman Powermate 5000 portable generator with the Robin engine. Found this on CL and while it was only $125...I later discovered it needed a new piston.

About $125 in parts it was back running again, still a bargain since now I know it's fresh inside. Unit starts and runs like a top, one thing I would like to know about this specific generator, is what should I expect for a "curve" of current from this thing?

Would it be linear up to it's max, or somewhat of a bell shape? Can I set it for 3600 at 1/2 load and expect it to hold that up to it's max or is it normal for it to drop off?

I have used it a few times to power some appliances last year but I feel it may be slightly out of whack. Carb is clean, governor is set to 3600 with about 1/4-1/2 load but it will drop to about 107 volts when about 3/4 load.

Does this sound normal or can I adjust the governor spring? I don't feel comfortable setting it to 3800 to allow ample voltage when loaded..should it not hold the speed give or take a a few RPM's?

Another idea is there an aftermarket voltage regulator that's under $150 or so that I can use inline with the generator to the main panel?

I plan on getting a Generlink after the first of the year just to keep everything simple instead of a gen-ready load panel....about the same $$$ when you add in breakers and such.

 

[flanso]

I have an older Coleman Powermate 5000 with a B&S. I plug a 110 volt electric clock with a sweep second hand into the generator. I adjust the generator's speed to the point where the electric clock's second hand is synchronized to the one on my watch.

 

[Al]

Get one of these. Plug it inside the house.

 

[JTK]

You should post the question over in the mower/small engine forum, but yes, it is common for the voltage to fluctuate on these based on the load you put on them. Most everything you plug in today has a power supply on it that will handle the highs and lows within reason. 107V is on the low end for 3/4 load, but it you set it up and load drops, output V's will go up. It's a balancing act.

Joel

 

[greenaccord02]

Something I do is use a UPS to buffer the current and normalize any peaks and peaks and dips for stuff like your computers, TVs etc. As far as refrigerators and stuff like that goes, their power supplies could care less about a little fluctuation.

 

[JHZR2]

Originally Posted By: flanso
I have an older Coleman Powermate 5000 with a B&S. I plug a 110 volt electric clock with a sweep second hand into the generator. I adjust the generator's speed to the point where the electric clock's second hand is synchronized to the one on my watch.


wont that set frequency, not voltage?

 

[QuadDriver]

I have an older maxa ER 5000/6250 powered by a 10hp techumseh.

It runs pretty stable at 60hz - THAT is what you set with engine RPM (3600rpm/60 seconds = 60hz)

your voltage flux is due to thus: your genset is 220v, as the load draws down the side of the coil you are using, the OTHER side is increasing. until you approach coil saturation, the genset will put out 220v net.

how to fix or alleviate: put a dummy plug in any 110v outlet that ties neutral to ground. warning, this may be (in fact will be) against NEC for separately derived systems if you are powering a part of a fuse panel (where the panel is grounded according to code).

this act will hold the voltage a little closer.

or: if you are driving high current 110v ac devices, see if they are 110/220v switchable and simply move the wire to make em run 220v (they will run better anyways)

or: use the twistlock to make a 220v sub panel and power an equal load from BOTH sides.

ps: motor, especially induction motors are VERY voltage sensitive.

DC stuff that uses a transformer is actually fairly voltage/frequency tolerant due to the VR and caps inside.

a lot of high quality stuff today are using rectifiers on the AC mains to produce HiV DC, then using inverters to produce 'pure' squarewave AC at a much higher frequency (about 4khz usually), then rectifying that to produce hyper clean DC. My plasma cutter is a good example - a hi-freq square wave inverter lets you cut serious metal from only 12-15amps of 110

Last solution: spend major coin to get an inverter genset like the honda EUxxxxis or the yamahas Exxxxis models. they present the proper voltage/frequency up to the capabilities of the motor.

 

[meep]

some beautiful posts here. bottom line, don't mess with RPM as that affects frequency more than voltage. these "jobsite" gensets provide basic power and a lot of it, but they are crude compared to most utility and inverter sources. you will find that at light load, the voltage can be high, 127+. You can run a dummy load to get the V down, at the cost of fuel burn, when it's too high.

btw, congrats on the purchase. that's a great deal, and the robyn engines I've known have been outstanding. wonder why it needed a new piston. ?

 

[QuadDriver]

if the clock gets the timing signal from the line (which the older ac motor clocks did) then it will work....

personally I prefer a freq counter that I use for rebuilding older stereos but his idea is great lo-tech - love it!

 

[punisher]

I have a genset pretty close to that, PM043500. It ranges 124V ~62hz to 118V~59hz loaded.

Ditto on the Kill-a-Watt, very useful.

How did that engine trash a piston? They are usually dead solid reliable.

 

[Slick17601]

I'm curious too what took out the piston. My Dad recently gave me an Echo 5500E that has at least 2,500 hours on it and the engine runs perfectly. It has that many hours that it literally wore out the throttle shaft in the carb. It took awhile to get the parts but I put in a new throttle shaft and it runs like new.

 

[i6pwr]

When I test ran it, it ran perfectly...very solid and quiet. I took it home and needed a flash to get the juice flowing so I wanted to let it run for about 10 min and change the oil.

After about 5 min I started to hear a very faint knock. After a few more min it became very pronounced...not a hard knock but I know what that dreaded sound is.

I drained the oil and cought some of the oil and noticed metallic flakes...very small. Refilled the oil and put a load on it...definately a rod knock.

Not sure what the clearance was off hand but definately out of spec on the main journal. Figure a new rod warranted a new piston so for about $250 total at least it's fresh....including the price of the generator.

I tried to call him back to see what the deal was....mainly to touch base and satisfy my curiousity....no answer..figured oh well, I ended up with the better deal....that's the risks of CL I guess.

Have to say, that's the easiest small engine (over 8HP)I have ever worked on, very well thought out.

I don't plan on using sensitive equipment with it, just the fridges, air handler, fireplace blower, lights, microwave....well pump if possible.

Pump is 575' down and I believe 1 HP.

Oh....forgot to mention, I can rewrite the swear word dictionary after trying to get the stator off the mainshaft.

 

[meep]

Originally Posted By: i6pwr


Oh....forgot to mention, I can rewrite the swear word dictionary after trying to get the stator off the mainshaft.

what did you have to go through for that?

 

[JTK]

Originally Posted By: i6pwr

Have to say, that's the easiest small engine (over 8HP)I have ever worked on, very well thought out.


That's good to know! I don't know much about them, other than they always looked well laid-out to me and have always been installed on hi dollar items.

Joel

 

[i6pwr]

Originally Posted By: meep

what did you have to go through for that?


I mentioned stator...I meant rotor...sorry

A carefully placed 2x4 on it's end, on the end of the rotor.

Some big, white-knuckle swings with a 3lb sledge and it finally popped off. The plastic end where the brushes rub is right there...one bad hit and you bought a rotor.

Just remember to keep the bolt threaded to keep the rotor from falling.

 

[JimPghPA]

If the load you are putting on that gen-set is 120 Volts and you are only using one of the two 120 volt sockets, than the maximum load you can put on it would be 1/2 of rated.

That unit puts out 240 AC. That is split into two 120 AC circuits. You can not tie those two together because they are out of phase. You can load each side of the 240 ( each 120 ) with anything up to 1/2 of the rated wattage of the generator. The only way to pull the rated wattage from that generator is to load each of the two 120 volt outputs with 1/2 the rated load, or load the 240 with rated, or a combination of part of the load on the 240, and the remainder fairly equally divided and applied to each of the 120. It is best to load both half's as equal as you can. If you put more than 1/2 the rated load on any of the 120 volt sides you are over loading the generator and can damage it. These generators are easily damaged because the circuit breaker is too slow to protect them.

On hot days it is best to de-rate the maximum continuous load to something like 80 percent of normal. It is also a good idea to plug a large box fan into it and blow the air from the box fan to aid the cooling of the engine and electrical section. Be sure that the direction of any added air flow is aiding and not fighting the existing air flow caused by the engine cooling fan built into the housing by the pull rope.

 

[01rangerxl]

Originally Posted By: i6pwr
When I test ran it, it ran perfectly...very solid and quiet. I took it home and needed a flash to get the juice flowing so I wanted to let it run for about 10 min and change the oil.

After about 5 min I started to hear a very faint knock. After a few more min it became very pronounced...not a hard knock but I know what that dreaded sound is.

I drained the oil and cought some of the oil and noticed metallic flakes...very small. Refilled the oil and put a load on it...definately a rod knock.

Not sure what the clearance was off hand but definately out of spec on the main journal. Figure a new rod warranted a new piston so for about $250 total at least it's fresh....including the price of the generator.

I tried to call him back to see what the deal was....mainly to touch base and satisfy my curiousity....no answer..figured oh well, I ended up with the better deal....that's the risks of CL I guess.

Have to say, that's the easiest small engine (over 8HP)I have ever worked on, very well thought out.

I don't plan on using sensitive equipment with it, just the fridges, air handler, fireplace blower, lights, microwave....well pump if possible.

Pump is 575' down and I believe 1 HP.

Oh....forgot to mention, I can rewrite the swear word dictionary after trying to get the stator off the mainshaft.

That is kind of an unusual failure for a Robin engine in my experience. Overall they seem to hold up about as well as Yamahas.

I have noticed lots of badly fouled spark plugs on Robin engines though, so keep an eye on that.