Micro CoGen.

Quote from: mobile_bob on November 24, 2012, 11:40:58 AM
how are you measuring the temp?

you state that it gets so hot you can't hold your hand on it?
if it is anywhere near 200plus degree's you will likely come away with a blister
if you even so much as touched it, let alone tried to hold your hand on it.

is it possible that the thermometer you are using is off a bit?

at about 140 F it is hard to keep your hand on something for any length of time.

just wondering thats all

bob g

I am measureing it with a infred heat themometer.  From what I have measured objects, I would say it is pretty accurate.  It is so hot you cant put your hand on it.  I will check with the motor rewinder and see what he says.  I am afraid if I let it run for any length of time it would cook it.  Its just strange that it is not making any non normal noises and seems to have proper out put.  I cannot test it to its full rated capacity of 8.5 because my engine starts bogging down.  I orginally had a 6kw Leroy somer on it and felt if I installed the 8.5 that it would be a able to handle a surge load a little better than my 6kw. although my full demand load is only around 4kw.

While we are on this subject. This gen has 3 coils. One is the exciter coil.  I asssume this regulates the voltage  or has something to do with it.  Then there is a primiary coil and a secondary coil.  Exactly what is the funcition of these coils and how do they work?

Quote from: mobile_bob on November 23, 2012, 05:41:00 PM
this is not by chance a 3phase head is it?

if it is, is it connected in delta?

if so he might have to reconnect it in wye to keep the circulating currents down,
this is caused by imbalance between phase coils, causing a circulating current.
that would heat the head up.

bob g

No, its not a 3 phase.   

It is a Leroy Somer 8.5 gen head.  There is no way he can spin it up to test it due to the way it connects to the engine.  I might have to trailer the whole thing to him as it is a light tower plant. It doesnt seem to be pulling the engine down and seems to have proper voltage on each branch of the 240.  I hooked up 4 1500 watt heaters )2 on each branch and dropped some but not alot (110v) But like you fellows said I dont think it should run 220-230 with no load on it.  It gets so hot at that temp you cant hold your hand on it and its winter time too.

I have a generator head I just had rewound.  With little or no load the gen head shows to be about 230 degreees.  The gen seems to have the proper voltage and out put under load.  I think this is too hot.  another gen I have runs about 160.  Any opinions. I am worried that under load for any length of time it might burn up the windings.

Thanks alot fellows for the information. "ask and you shall receive".  Again thanks.

Is there a web site or can any one give me any advice and information on hand winding a filed coil.  I have a Leroy-Somer 8.5 kw generator that has a burnt field coil.  No replacement part from Leroy-Somer.  Really dont want to replace it with a universal gen head.  What would I get into if I tried to hand wind it? Is it possible, any tips.  I took it to two electric motor rewinders and they said they couldnt do it.  I did drop it off at another rebuild shop in Cols. Oh. this morning.  The fellow who determines if they could do it or not and how much was not there today so I left it.  I am expecting the worst and may have to try and rewind it myself. I have seen some old timers do it but they are all gone to the great beyound.  I had one hand wind a 3hp air compressor motor for me over 30 years ago and it is still working better than new.

Thanks, that was what I was afraid of.

Just purchased a 8.5 kw gen head, sight unseen, fellow swore on his mothers grave that it was working when taken off (engine blew)  I have not mounted it yet as it is very labor intensive to mount it on my engine. But upon examening it very closely, I find one of the field windings that I am questioning.  It looks like it is burnt some what and looks like the insulation is sort of flaked off in places. (other windings are ok.  Is there a way to check it to see if it is shorted?  I think the book says 0.33 ohms of resistance.  Would that little of resistance show up on a ohm meter?  If I decide to use it, should I coat the windings with varnish or shellac or purchase a can of spray on winding insulation, and coat it good??

My pump is a 3/4 hp about 6yrs old. (well  depth is about 70ft with 55' 0f water) It is a submersible with capacator in the pump if it has one.  Read some where that starting elec motors that sometimes you can move up one size on your gen to aid in starting.   Remember my gen is handeling the total house load fine and once the pump kicks on, it is fine.  Going to talk to someone who sells Marathon gen heads and get his thought.  Engine does not seem to labor when running all the loads I put on it.  Just a blip, causing lights to dim for just a second.  If it doesnt hurt any thing might not bother with it.  Just worried at the right conditions existed that it might nause one of my freezers not to kick on if this all happened at the same time.

Quote from: hwew on August 19, 2012, 04:12:41 PM
Bring the rpm's up so you get 63 Hz, than give it a try.

The generator head might not have enough surge to handle your well pump.

6-Kw is not much to start the average submersable well pump. My well pump manufacture recomended that a generator needs to have at least 9000 watts surge for my well pump.

Henry   

I think you may have the right answer.  This gen does not have a AVR, only a capacator and I replaced it with no improvement.  My old gen I think had a 7kw surge and a 6kw run.  The well pump started fairley good with it, still dimed the lights some but I figured with thia Leroy Somer gen head which is about three times as large would do the same thing, but must not have quite enough surge.  Thats why I was thinking of getting the 8.5 kw gen head and put it on.  I really dont neeed any larger capacity at run,, as I am only pilling around 3.5 kw with every thing I run except the well pump.  I just dont know if the D850 engine will handle the additional surge.  The 8.5 kw is the same size physically, must be differnt windinings in the fields or rotor.























a

avr

This is a light plant and that might be part of the problem.  I have been told that the governor does not work like on most gen sets.  Most 6kw light plants have 4 1000wt bulbs and that leaves 2kw reserve.  I understand they just set the speed at 60hz with what ever load they have on them.  I have a volt meter and hz meter, I went down to my bulding awhile ago and fired the gen up and here are my readings.  At start up I have it set at about 132v and 61.3hz add one 1500 watt heater and reading is 127v. 60.3hz, 2 heaters 119v and 59.3hz (this is about what my house hold load is) 3 heaters 114v at 58.9hz, 4 heaters 104v and 57.7hz.  Gen does not get hot.  I can slightly incerase engine speed with 4 heaters on (6kw) and the hz and voltage comes right about where iit is supposed to be.  I dont see any way to adjust the sensitive to governor setting so it will pick up speed slightly when applying load.  Its just the surge of my well pump that I am worried about.  When I get time I will hook my meter up and see what the figure is when the well pump kicks on.  I imagine it is dropping to around 100v. but comes right back up.

The engine has been serviced, air, fuel filter ok, engine runs ok, no smoking, question is will it run the 8.5 kw gen head.  I know this is a non current engine.  I did see where they used this same engine on a Lincon welder with a 10 kw gen head.  My worry isntt getting the full 8.5 kw out of it, just lets say 3.5 kw load on it, will it take on a monentary surge better than gthe 6.kw, when the well pump kicks on.

I puurchased a Coleman light plant with a Kubota D850 engine and a Leroy Somer gen head.  It is rated at 6kw. continous.  I was going to use it to replace my 6.K gas gen set.  My house hold load is some where around 3000 to 3500 wat.  Lights, Fans, frezer. ref.  Without intermitt a 3/4 well pump (220)  Got it hooked up and everything works great except it really (almost puts lights out) drops the voltage for a few seconds when the well pump kicks on.  With my gas gen it dropped some but not this much. (I think governor kicked in)  I  have a chance to purchase a 8.5 Kw Leroy Somer gen head. I know that you usually figure 2 hp per kw.  But if I dont put any more of a continous load than on the 6.kw, would this engine handle the 8.5 and would this help in starting my well pump?  I have heard that for the most efficent use of your engine 80% load is what you should have on it. I notice when I was testing the gen that after putting 3 1500watt heaters that it started pulling it down and the 4 one voltage started dropping.  I would say that about 4500 watt is the max productive point.