Power Equipment Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter #1
Hey guys! I have a Lima 10kw alternator generator mounted on a trailer, a mobile power unit. It was working fine one day, i had a few things on to keep it under load as a do every month or so and when i came back i had lost voltage output. When i pulled the fuses (They are fuses for the voltage regulator i believe 5 amp) one had blown. I replaced it again and immediately blew. So i looked inside with the voltage regulator and found one of the ice cub relays was rusty and looked like it had water in it.

So i just ordered another one, well two, replaced it, replaced fuse, now it blew both (identical relays swapped wire to terminal exactly) so i swapped the other one as well so there are two new relays. Blew both fuses again. So i figured maybe the new relays were drawing more power so i swapped in 10 amps. blew both of them, decided i wanted to burn the thing down trying to solve the problem, swapped in a 20 amps, was running fine for about 30 seconds, with load on it, ac compressor, blower etc. then i lost voltage on the gauge, and smoke started coming out by the voltage regulator but the alternator windinds are located directly below it too. The voltage regulator and wires going to it didnt feel warm, so what did i do to it?

I can order another 10kw regulator from China and wire it in, but i dont know if that's the problem, i think the alternator may be damaged, what should i check first? I know i obviously damaged it and it wasnt the smartest thing to do but at the time it seemed logical haha
 

·
Banned
Joined
·
380 Posts
Assuming the engine is not loading up under lite load, Ohm the exciter stator, from the reg F+ and F- wires and check for a short to ground. If all is OK replace the Voltage reg.
Never replace fuses with a larger size, that is a Disaster in the making and you can hose up want was good prior, no matter the equipment.
Lima's are tough old girls, but over sizing fuses is a big no, no, even with them.
Hope this helps,

Kenneth
 

·
Registered
Joined
·
19 Posts
Discussion Starter #3
Thank you, upsizing the fuse was my last resort thinking maybe the different brand 8 pin relays required more power.

So i should cut the F+ and F- wire, then test resistance between each one between that and the frame o the alternator? I apologize i know nothing about generators, i dont know that the ice cube relays go to anything related to it but i did noticed one had water in it and was rusted so i assumed that was the root cause.
 

·
Banned
Joined
·
380 Posts
The following is assuming you do not have a Lima Mac/R machine.

Remove the F+ & F- wires from the reg and with your Ohm meter read the excitation field circuit F+ thru the stator and back via the F-. I don't know the spec off hand but on a 63V excitation circuit it should be somewhere between 9 an 50 Ohms. If that is OK, hook up to either one with one lead of your ohm meter, with the other lead hooked to the barrel, AKA outer case. That should infinity. If you have a Megger it should read > than 2 meg Ohm at 600Vdc
Hope this helps,

Kenneth
 

·
Registered
Joined
·
19 Posts
Discussion Starter #5
Here are a couple of older pictures of where the voltage regulator sits i took the last time i had it apart.

http://imageshack.us/a/img152/8531/sam0458e.jpg

http://imageshack.us/a/img35/5535/sam0459s.jpg

It's a Lima 250, 12 lead, single phase 10kw

Here is the manual for it

http://www.marathonelectric.com/generators/docs/manuals/SB364.pdf

And i attached an image of the data plate, its power by a 3 cylinder continental gas motor.

I really appreciate you taking your time to look into this for me, i dont know anything about generators but i'm confident i could fix it if i just knew what i destroyed :)
 

Attachments

·
Banned
Joined
·
380 Posts
It's not a Mac/r. That reg is a std Basler, number APR 63-4 that is still in the parts chain. They are sold at many quality dealers and Distributors.
Davidson Sales in Fla would be my first choice, but depending on where you live may dictate who you have to buy from. Davidson can tell you who if so. You can look it up via the info above, and many other regs will work on that machine, but they have to be wired in correctly.
One other thing, that reg like most others can have (or not)a voltage trim pot (adjustment) be sure it works correctly or the voltage can be either very low or high if it's set wrong or defective.

Kenneth
 

·
Registered
Joined
·
19 Posts
Discussion Starter #7
Thanks! Do you think that the regulator burned up or i burned up the regulator and that's all it is? I'm not sure where the smoke came from, it just came out of that general area, it was a definite electrical burning smell. I will check it out the next chance i get, hopefully tomorrow. Those are the two ice cube relays i replaced, one definitely had water in and it and was rusted, i have no idea how it got in there as its a covered unit but i replaced them both just to eliminate that possibility

This is a unit i have used regularly and works reliably other than the ammeter terminal vibrating loose during the hurricane but has work hours fine since i fixed it. Its very strange.
 

·
Banned
Joined
·
380 Posts
That price is rich. Wait and contact a dealer. The water got into the relays do to the relays being mounted upside down. The H2O was condensation build up. No Relay/s are ever supposed to be mounted that way. If you want to leave them that way drill a small hole for the condo to drain out. Test the field circuit before you buy anything, test, do not guess. Look up bench testing a Basler APR 63-4 as you can test it with a 100 watt light blub on the F+ an F- leads while supplying it 240Vac from a wall outlet, or by using a Variac and a transformer. Those regs are tough with the proper fuses, but now w/o having it in front of me, I can't say if you smoked it or not.

Never guess, always test, cheaper in the short or long run every time.

Kenneth
 

·
Registered
Joined
·
19 Posts
Discussion Starter #12
Thanks Kenneth! i will try to pull it out and check it all out tomorrow, good idea about drilling the relay i will do that with the new ones too
 

·
Banned
Joined
·
380 Posts
Yes the Marathon reg will work, it is a 63-4 in open config, wires the same ect. Read and follow the instructions, but like I said above, test everything first don't just guess and throw money at it. By the way that Marathon reg, is made by Basler as well.
63 is the max continuous voltage and the 4 stands for max continuous amp, those are not forcing numbers which are much higher but for a very short time frame.

Kenneth
 

·
Registered
Joined
·
19 Posts
Discussion Starter #14
Hey Kenneth, i finally got around to checking out the voltage regulator. Removing the F+, and F- wires connecting them together i got 29 ohms. Checking from both the F+ and F- wires to the case of the alternator i got between 10-40 ohms. I am guessing this indicates a short somewhere. What should i check first to try to narrow down the problem?
 

·
Banned
Joined
·
380 Posts
Hey Kenneth, i finally got around to checking out the voltage regulator. Removing the F+, and F- wires connecting them together i got 29 ohms. Checking from both the F+ and F- wires to the case of the alternator i got between 10-40 ohms. I am guessing this indicates a short somewhere. What should i check first to try to narrow down the problem?
29 ohms is a OK reading for the exciter stator, but you should read infinity**, from either F+ or F- to any ground when they are both unhooked from the reg.

Trace the exciter wiring (F+ an F-) all the way to the stator and back.

A exciter stator, or it's wiring, having issues will blow a regulator very, very quickly, as the fuses are for the primary(voltage sensing) side only.

** infinity on a std ohm meter. If using a Megger set at 600Vdc the lowest reading should be 2 meg ohms, anything lower, dry the unit per specs and re-meg. If the reading is still lower than 2 meg, the component being tested needs to be re-wound and re-dipped(VIP). All this assuming you are working on a 600Vac unit of less. For 1Kv or higher components the specs or totally different.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #16
Thanks! I do have the regulator unhooked and i have continuity through both the F+ and F - terminals. I have pretty much written it off at this point. I just ordered another 10,000 watch cheepo generator for now, Duromax or something, and i am thinking about pulling the generator from the trailer setup and replacing with the smaller one.

I'm not sure if you have any interested but for taking the time to help me with all of this you are welcome to have the Lima alternator and great running 3 cylinder continental gas engine for free if you would like. I will pull it out and put it on a pallet when i get the chance. I have decided this repair is beyond the time and effort i want to spend with my limited/lack of knowledge on the internals of these
 

·
Banned
Joined
·
380 Posts
Thanks for the offer, where is the unit located at?
 

·
Registered
Joined
·
19 Posts
Discussion Starter #18
I'm in Felton, DE. I did measure the F+, again and it seems like it may not be making contact. It's an auto range finding multimeter and it kept jumping from Ohms to Kohms to Mohms, but F- definitely made contact at about 20-30 ohms.
 

·
Banned
Joined
·
380 Posts
That is saying there is a problem. I'd check the Field wiring complete before condemning it. It might be something as simple as just one wire was rubbing and burnt threw. The other thing it could be is if the rear bearing went out and dropped the rotor, but you should have herd something long before that happened. Just trace the F+ & F- all the way down, you might get lucky. Lima's are tough old girls and do not give it up very easy.

De. is a little far from Alabama, but again I thank you for the offer.
 
1 - 19 of 19 Posts
Top