Powerless in CT... Generator Issues... Please help!

[Freefall_Doug]

Thought I would throw this out there, maybe some one knows next to nothing about generators, which would be a lot more than me. If any of you have any ideas about the issue I am having with my generator I am all ears.

My town is 100% out of power, and I probably won't get it back on for many days.

I bought off craiglist a Multiquip 5000watt generator which is powered by a Robins/Wisconsin engine. The unit is pretty old and well used, it was a rental unit at one point.

Engine is running fine, it has auto idle, and appears to be in pretty good shape.

The generator itself has a 120 and 240v output.

It has a 3 prong twist lock but I switched it to a four prong twist lock to match my generator cord. I left the ground, G on the twist lock, unwired for now because the generator only had two hots, X & Y, and ground which really is a W nuetral as far as I know. When I measure with a multimeter across the twist lock X & Y, the two hots, I get 250V.

The generator is not running electrical loads well at all.

When I first had it running yesterday it fired the furnace for hot water, got the fridge running, well pump,. and all the other circuits on the transfer switch. It started out awesome and I was pretty stoked.

Then it had trouble putting out 120 for the furnace, fridge, etc. I can get it to power some CFL bulbs but I need to flip a few switches in the house to get it to output. For example if I turn the bathroom fan on the fan won't really start up, but it will cause the generator output to kick up and then the CFL's in the living room fire up. If I turn the fan switch off the CFL's in the living room go off.

If I try to start the fridge most of the lights turn off or dim.

The unit has no problems running the well pump though with is 240v, and the highest draw in the house. I can hear the generator change sounds when the load of the well pump is on it, it lugs a little but the well pump pressure keeps up, and it seems to be the only thing the generator is running well. Very strange since well pumps are something that generators often struggle with.

I thought maybe one of the two hots was running weak so I swaped them in my generator cable, x for y, maybe the hot running to the 120v circuits would then be the good output. No dice, still same thing.

I am a bit stumped. I really would like to get this going. My town is 100% out of power, and no new generators can be found in stock anywhere. I don't think I will have power for a few days. CT power infrastructure is in pretty bad shape.

Thanks!

 

[mrb]

whats on the other end of your generator cord? how is it connected to the house?

whats the model number of the generator? I have a feeling a 240v 3 pole (6-20 or 6-30) receptacle on a construction generator is not going to supply 120/240.

Does the generator have a 'max power' 120-120/240v switch?

the ground wire from the 3 pole receptacle you removed, where does it go? To the chassis or into the generator head?

I would not run this until we get the issue sorted out. You risk damaging appliances and electronics.

 

[Freefall_Doug]

The generator cord is wired in to a transfer switch. I am operating on the assumption that this is all correct, which makes sense because all items on the transfer switch operated correctly for the first glorious hour that the generator was properly powering everything in the house.

Not sure of the generator model number unfortunately.

The generator has a switch that says 120v when flipped up, and 120/240v max power when switched down.

The generator had a 3 prong twist lock. It has two hots and a nuetral, the 3 prong twist lock actually called the nuetral ground? It called it ground but I actually think it was the nuetral. I don't think generators started having the fourth connector, the common ground, until later on. The two hots on the original 3 prong were X and Y.

I went from a 3 connector to a four connector for the 240 outlet.

The generator wires inside are not color codes so bear with me.

The black wire in the generator cord is wired to y, it received one of the 120v hots.

The red wire in the generator cord is wired to x, it also received one of the 120v hots.

The green wire in the generator cord is wired to G, I did not hook up any wires inside the generator to the G on the 4 prong female. There was only three wires in the generator to start with.

The white wire in the generator cord is wired to the W, it received the wire that was orginal wired to the non hot prong inside the original twist lock three prong. So was this ground, or was this actual a nuetral which is being called "ground".

My hunch is with the brushes in the generator portion of the unit? If things were wired wrong why would everything have worked correctly for a period of time, and then things stopped working right. I think if the wiring was wrong it never would have worked right?

 

[mrb]

i cant really help more without the generator model number.

Some of these generators that have a 240v 3 pole twistlock cant output 120/240v on that connector. The ground wire you took off the old 3 pole receptacle -where did it go? Did it connect to the chassis, or did it go somewhere else?

once i re-read your original post and saw the part about turning on lights and things starting to work, you have no neutral and your 120v loads are connected in series. There is no neutral connection to a 0v center tap on the 240v winding. This is causing voltage swings on your 120v loads and you are running a high risk of damaging things.

try to get the generator model number -it has to be on there somewhere....

 

[Freefall_Doug]

I believe the ground wire in the 3 prong switch went back into the motor. I have to trace it again to make sure. There are more than 2 wires coming out of the generator housing.

Based on my readings with my mutlimeter I thought that there were two 120v windings that combined together to make the 250v output. When I measure between the X and W on the four prong I read a little less than 120. When I measure between the Y and W on the four prong I read a little less than 120. When I measure between the X and Y I read 250.

Thanks Mrb. I will search for the model number when I get back home. I appreciate the thoughts so far!

 

[mrb]

there will be 4 wires coming from the generator to the 120-120/240 switch. Then the receptacles will all be wired to that switch. You do have the switch in the 120/240 position right?

also post the model of the transfer switch on your house. Does it switch the neutral?

 

[Freefall_Doug]

I believe this is the model transfer switch.

http://www.gen-tran.com/eshop/10Expand.asp?ProductCode=20216V

Install manual.

http://www.gen-tran.com/assets/pdfs/vintageInstall.pdf

 

[Freefall_Doug]

Ok back home by the unit.

Model # is GRF-5RZ or MQ followed by the same.

All reading points to gentran transfer switches not switching nuetral.

 

[mrb]

Ok I got ahold of the manual and wiring diagram for that generator. You cannot get 120/240v from the wiring to the 240v receptacle. The ground wire just goes to the chassis and does not contact the neutral. If you understand wiring diagrams PM me your email address and ill send the doc to you. It is possible to get 120/240v output with a neutral but it requires a minor modification to the generator and you have to make sure you never have the 4 pole receptacle connected and the switch in 120v mode. You can make the mod but I assume no liability for you doing so.

 

[Freefall_Doug]

Mrb, thanks for the response.

I traced the wires and realized just that.

I found the two nuetrals for the 120 windings and rewired the 4 prong.

It is working like a charm now. I agree about not flipping the 120 switch. If you could send me the wiring diagram I would be in your debt!

I think I might take out the switch and all the other outputs to simplify.

The good news is the fridge and other items seem unscathed, the bad news is the oil burner seems dead as a door knob.

Ugh!

Thanks for all the replies.

 

[mrb]

if you tied the 'neutrals' together dont EVER flip the 120v switch. The switch connects 2 seperate windings in series in 240v mode and in parallel in 120v mode. One of the 'neutral' wires becomes a hot in 120v mode.

 

[mrb]

edit: the ground pin on your 4 wire receptacle should be bonded to the generator chassis.

 

[Freefall_Doug]

That is what I did, and that is why I will probably strip out the switch and all the other outlets.

I did wire up a ground to the previously unused G prong on the 4 prong twist lock.

Thanks for setting me on the path of nuetral problem, I never would have figured that out without your post!

 

[Freefall_Doug]

I can't win.

Last night generator was putting out great.

This morning it won't excite and put out power. No juice from either hot.

Guess it is going to be one of those weeks.

I never should have shut it off!

 

[Freefall_Doug]

OK, I think I have no firmly established myself as the village idiot.

So when I turned the generator off last night I didn't disconnect the load first.

All researching points to two thing... A: I am a *****. B: When you leave loads connected to a generator and turn it off it can demagnatize the genset.

I saw this gem on a google search:
http://www.endtimesreport.com/dead_gen.html

So I am going to have my neighbor drive his genset over after I make the contraption described.

I think if I "jump start" the first 120v coil I can then get the other one going and god willing I can hopefully get a working generator, again, by tonight.

 

[mrb]

ouch. never turn a generator off without disconnecting load. As the motor spins down the voltage drops and the frequency is all over the place. That can cause alot of damage to things with electronics in them.

 

[Freefall_Doug]

Yeah like I said, village idiot. I would have been way ahead of myself if I never picked up this genset!

Luckily nothing with fancy electronics was a load in the house, just light bulbs. And the furnace controls had already been fried during the nuetral fiasco, so nothing to with fancy electronics to damage... further.

Do you think I am on the right path with my assumption that I demagnatized the genset.

Nothing changed between last night and this morning, despite my smooth move. Initial multi meter testing don't point to any burnt out current paths.

 

[nehog]

...
Do you think I am on the right path with my assumption that I demagnatized the genset.

Yes, you are probably on the right track. No absolute promises however, only trying it will tell. Some sets you can even use a small battery to re-magnetize the unit, there are a bunch of writeups on the web on how to do it.

Do be *very* careful, if you do manage to 'restore' it, don't zap yourself when it starts putting out power.

 

[mrb]

the troubleshooting section of the manual for your generator lists the following as causes for 'Alternator fails to generate':
Shorted wiring
Burnt out armature field wiring
Brushes not making contact (i would check that first)
Burnt out AVR
Malfunction of voltmeter

In that this generator has a seperate excitation winding, i dont know if turning it off under load is going to demagnetize it. This is where my expertise ends.

you still need to PM me your email address so i can send you the manual.

 

[Freefall_Doug]

Mrb, MultiQuip actually emailed me a copy. I guess the read my email last night, and I missed it until today. The gentleman there in the tech document section was able to guess the model based on the description, I am pretty impressed.

I wasn't able to "flash" the generator to get it working again.

I ended up getting a new Briggs and Straton 5kw generator when the local hardware store got a few pallets in. It is way less beefy than the MultiQuip, but it puts out power.

Rebuilding the MultiQuip is going to be a winter project for me! I really like how heavy duty it is, all the features it has, minus the no power option!

The BS came with a nuetral bond, that thanks to generator number 1 and mrb I knew wouldn't work with my transfer switch. I was able to turn it in to a floating ground, and switch the plug to my 4 prong twist lock because it had a 4 prong of a different type.

Now I am purring away with power again.

Friend is coming over to check the control until on the burner.

Maybe I will be back on my feet soon, I bet sooner than that power company gets their stuff in order!

Thanks All!

 

[mrb]

glad to hear youre back up and running

 

[Freefall_Doug]

Thanks mrb.

Control unit on the burner is burnt.

Good news is that it isn't a fancy high eff. burner with fancy digital controls. My friend thinks the part is only going to run 100-200.

Once I get grid power back is there any inspecting I should do in the panel to check for further issues? I assume other than the oil burner control unit I didn't do any perm damadge, as the new generator is powering everything else OK.

 

[Milton Shaw]

There was a thread on here about how to reflash a generator, using a plugin electric drill. Plug it into generator, and turn chuck by hand and it would generate enough current to reflash and when the drill starts turning by itself you are fixed. Haven't tried it but sounds like it would work. As small brush motors can be a generator if turned by hand.

 

[Frank The Plumber]

This was well worth the read. Bumping it to give others a chance to read it. Thanks.