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Onan Generators

Protection of Downstream Loads


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  #11  
Old 01-11-2018, 10:46:27 PM
rmchambers rmchambers is offline
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Default Re: Protection of Downstream Loads

I have a 3600W Trace/Xantrex inverter and 8 golf cart batteries. I run the loads I want to run from this. (at night it's quiet) the entire output from the generator goes into this device when I fire it up. The inverter will send power through to the loads and charge the batteries up, if the generator stops or gets wiggy, the inverter will drop off the power and work like a UPS and feed the loads.
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  #12  
Old 01-12-2018, 06:46:01 AM
armandh armandh is offline
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Default Re: Protection of Downstream Loads

Yes you can blow stuff up with a generator

my late friend Tom had one that did this until I fixed it.
Mr "drier outlet back-feed" gave me his old "problem" generator when
he went to a 200A transfer switch and twice as big in generator size.
gave = I paid the $75 late fees on the trailer title transfer and for the new plates.

the problem; it was running out of governor spring under heavy load.
rather than move the working end closer to the pivot
he tightened the adjustment end, but when the load came off,
HZ and V went through the roof, and fritzed goodies. [induction regulated]

I went to a longer softer spring that, after some trial and error, held 60 HZ
from a light load through breaker opening overload without hunting.
and learned a lot about mechanical inverse feed back!

positive feed back [over center spring] or
inverse feed back [above the tangent spring]
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Last edited by armandh; 01-12-2018 at 07:19:10 AM.
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  #13  
Old 01-12-2018, 07:23:42 AM
motion motion is offline
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Default Re: Protection of Downstream Loads

Thanks for all of the replies. Mine is set up for 208v, three phase, 4wire. As other have said it's not super important but would be nice (belts and suspenders). It's something that I'll think about.
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  #14  
Old 01-12-2018, 10:17:36 AM
Leon N. Leon N. is offline
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Default Re: Protection of Downstream Loads

With all due respect did you really say this? "the problem; it was running out of governor spring under heavy load."!

What kind of a machine was that? And to try and correct the problem the way mentioned. Wow! Not a good idea. Sounds like it was not set up properly to begin with.
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  #15  
Old 01-12-2018, 01:32:54 PM
Vanman Vanman is offline
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Default Re: Protection of Downstream Loads

My 6-1/2 kw Kohler came with what looked like a piece of wire twisted around to make a "spring" for the governor. It would go from over 63 cycles to less than 58 when a 5 kw lamp was thrown on the line.

I did pretty much the same thing. Found a suitable spring and adjusted it until it would just not hunt. Problem solved.
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Old 01-12-2018, 03:17:19 PM
Newoldstock Newoldstock is offline
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Default Re: Protection of Downstream Loads

Quote:
Originally Posted by Vanman View Post
My 6-1/2 kw Kohler came with what looked like a piece of wire twisted around to make a "spring" for the governor. It would go from over 63 cycles to less than 58 when a 5 kw lamp was thrown on the line.

I did pretty much the same thing. Found a suitable spring and adjusted it until it would just not hunt. Problem solved.
Moving the spring closer to the fulcrum of the governor arm will increase sensitivity.
If the engine starts to hunt it is too sensitive and a different choice of spring might help.

Long springs have a more constant tension rate short ones are more progressive ( the shorter less likely to hunt the longer ones more )

A dash pot from a different carb might also help with hunting., but this will slow load responds time.

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  #17  
Old 01-12-2018, 07:04:59 PM
Vanman Vanman is offline
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Default Re: Protection of Downstream Loads

Yes, indeed not having access to factory parts I selected a fairly long spring to ensure that I would be able to adjust the sensitivity to be as sensitive as possible, ie just less than continuous hunting. It works great.
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Old 01-13-2018, 08:05:09 AM
armandh armandh is offline
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Default Re: Protection of Downstream Loads

same thing

a 7.2 KW K-582 powered 1800 rpm generator
1964 vintage and no knowing how many amateur repairs.

when the load went on the spring pulled the throttle open until it fully collapsed
way short of full open throttle, it was probably NOT OEM

finding the right spring at the right angle to give quick response with out hunting
through out the load range took a bit of experimentation.

Quote
Moving the spring closer to the fulcrum of the governor arm will increase sensitivity. if you don't move the other end to the original tangent
If the engine starts to hunt it is too sensitive and a different choice of spring might help.
but if the spring is within the governors ability to pull the throttle closed changing the angle of the fixed end changes sensitivity as well

less inverse feed back = more sensitivity and likely-hood to hunt

as you move the fixed end of the spring above the arc the first part of the governor pull has greater mechanical advantage
photo less/more sensitivity
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__________________
.
by using this free advise, you, your heirs, etc
absolve, save, and hold harmless the advisor.
CAVEAT EMPTOR
YMMV

Last edited by armandh; 01-13-2018 at 12:58:24 PM.
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