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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: chuckd on April 03, 2010, 02:26:30 PM

Title: Kohler inverter?
Post by: chuckd on April 03, 2010, 02:26:30 PM
Two topics here, one has to do with trying to figure out all the systems in my Liberty Prevost, and the other is the leak source on the heat exchanger.

In playing with some switches on the console that houses the ac unit, one was labeled inverter - off- kohler/shore, so I switched to inverter and some ac circuits came on, and a fairly large blower noise of some sort came from one of the bays, it was the bay next to the gen set and it sounded like it was coming from a fairly large enclosure with Kohler on the outside.  Did Kohler ever make an inverter? 

Second part, I took off the grates from the heat exchanger and can see that it is oxidized and there is water stains on the wood around it.  I am going to have to cut the under sink bottom shelf out to get at it, but it looks like it will all exposed when I do that.  That will be Monday's
project.  Why do I think that heat exchanger will be unobtainium?

Chuckd
Stillwater Mn
Title: Re: Kohler inverter?
Post by: robertglines1 on April 03, 2010, 03:32:46 PM
From what I understand the Kohler power is auto start 12v dc output to recharge your house batt that feed your inverter..
Title: Re: Kohler inverter?
Post by: edroelle on April 03, 2010, 04:47:52 PM
I am guessing, but this is what it sounds like to me -

The switch turns the inverter off, and activates a solenoid to run the coach off the Kohler generator or shore power.  Otherwise, the coach is running on inverter power.

Ed Roelle
Flint, MI


Title: Re: Kohler inverter?
Post by: chuckd on April 04, 2010, 12:54:39 PM
Okay upon further evaluation, it is not coming from the Kohler box, but right next to it, is a Honeywell DC-AC (inverter) device.  I have Marine Corps ears and fine detail about where sound is coming from is lost on me.  But now I know whats what, and Bob you are probably correct the 12 volts are coming from the Kohler device.

Chuckd
1979 Prevost Shorty
Stillwater Mn
Title: Re: Kohler inverter?
Post by: chuckd on April 04, 2010, 02:39:47 PM
Found it!  Honeywell sold this device to Redi-line and they still manufacture the device.  It is a DC motor that outputs 115Volts AC.  Perhaps a candidate in the future for a "real inverter, but who knows, it may just run and run.

Chuckd
Prevost shorty
Stillwater Mn
Title: Re: Kohler inverter?
Post by: Handyjim on April 04, 2010, 07:26:35 PM
I  believe it's a rotary inverter (actually a generator turned by a 12 (or 24) volt DC motor.) Some years  ago,  I was offered one by a guy who built up emergency equipment for fire departments. IIRC, he said it was, at that time, a cheaper way to get higher output than solid state inverters, which at the time were very expensive.  He said the quality of the power output was quite good.  Sounds like you might have a keeper!
Title: Re: Kohler inverter?
Post by: Damn Yankee on April 05, 2010, 06:03:08 AM
I just removed one of those from my bus since there was no need for it with 2 - 2500 watt inverters now installed. It is 3000 w 24 v belt driven generator and was labeled as an MG set?. Was probably a good source of clean over the road power in it's day and still is if you don't want inverters or run the gen set while traveling. Here is a picture of mine when it was in the bus.
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi734.photobucket.com%2Falbums%2Fww347%2FMichigander_Bob%2FMy%2520Bus%2520Conversion%2FP1010180.jpg&hash=98e3cfecbfe9c876cfbfe630865eb44dd604ff52)
Title: Re: Kohler inverter?
Post by: robertglines1 on April 05, 2010, 06:37:26 AM
Thanks for info ;I have learned more today and food for thought...Bob 63 and learn every day
Title: Re: Kohler inverter?
Post by: Depewtee on April 05, 2010, 06:01:49 PM
I too have questions about some of the components on my new-to-me bus, 1981 Prevost Liberty.  Here are a few pictures of items related to this thread.

Chuck D. - Is this what your Kohler "box" in the bay adjacent the genset looks like?.
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi215.photobucket.com%2Falbums%2Fcc210%2Fdepewtee%2FPrevostMarch2010067.jpg&hash=2b866868878476829f591978dd627e12faf6b6cb)


(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi215.photobucket.com%2Falbums%2Fcc210%2Fdepewtee%2FPrevostMarch2010068.jpg&hash=bb3db382a1cdede1bcbd624b3bc032f77a6f0833)


(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi215.photobucket.com%2Falbums%2Fcc210%2Fdepewtee%2FPrevostMarch2010069.jpg&hash=27edc08e706c9742b9c498c6d816272955f36bec)

Chuck D. - Is this what was making the humming sound?
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi215.photobucket.com%2Falbums%2Fcc210%2Fdepewtee%2FPrevostMarch2010063.jpg&hash=0a6f71f52a9c48d045dc7c3a2ad1d9c0b5ddaa74)

Any thoughts on these Honeywell inverters? 
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi215.photobucket.com%2Falbums%2Fcc210%2Fdepewtee%2FPrevostMarch2010064.jpg&hash=c5f8e65ce71755d9e141c3cfdef0e918b70edefd)


(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi215.photobucket.com%2Falbums%2Fcc210%2Fdepewtee%2FPrevostMarch2010066.jpg&hash=db0cec68887fa96e84b789d8c1ffec3d7bc4de71)

I have no idea how these operate.  I flip the switches to "on" and nothing happens.
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi215.photobucket.com%2Falbums%2Fcc210%2Fdepewtee%2FPrevostMarch2010065.jpg&hash=0edb6f04702e65b807625e08292cf0661fbe04c7)

Brian S.
Title: Re: Kohler inverter?
Post by: chuckd on April 05, 2010, 06:10:16 PM
Brian:

Still not sure exactly what the Kohler does, but I think it is the source of DC power to the dc to ac inverters.  Redi-Line generators is the new source for the Honeywell generators.  They have two models, the largest is 1600 watts which is the size that these inverters look like.

chuckd
Title: Re: Kohler inverter?
Post by: belfert on April 05, 2010, 06:24:44 PM
Wouldn't an inverter of this type be fairly inefficient?  You esentially are turning a motor with DC power that then turns an AC generator.
Title: Re: Kohler inverter?
Post by: JackConrad on April 06, 2010, 05:59:17 AM
Quote from: belfert on April 05, 2010, 06:24:44 PM
Wouldn't an inverter of this type be fairly inefficient?  You esentially are turning a motor with DC power that then turns an AC generator.

We had these on our ambulances back in the late 70s & early 80's. They were rarely used and because of the amount of 12 volt power required, were only used when the engine was running. These rescues had HUGE Leece-Neville alternators. The motor on the inverter was about the size of a starter. IIRC, they  produced a very "clean" sine wave power.  Jack
Title: Re: Kohler inverter?
Post by: Sean on April 06, 2010, 09:12:38 AM
30-40 years ago, inverter technology was still pretty rough around the edges.  Remember, microprocessors were new devices in the 70's, and even silicon power controls were new.  Back then, inverters were all discrete controls and had very coarse stair steps -- what today we call "modified sine."  Even the MSW inverters were pretty inefficient.

If you needed clean sine-wave power, you needed to use an MG (motor/generator) set such as the ones being discussed here.  For example, very large MG sets were common in critical data center backup systems -- in addition to providing very clean power from the UPS batteries, by having a very heavy flywheel between the motor and generator, they allowed enough time for the banks of contactors to switch from grid to batteries and back without a hiccup.

DC to AC MG sets have been obsoleted by modern microprocessor-controlled inverter technology and super-fast SCR controls.  Inverters, of course, still produce stair-step output.  But you can build one with whatever step granularity is required for the application, and let toroidal transformers and filter caps smooth it out.

As has been noted, these MG units require a good deal of power to get started, and they are inefficient compared to inverters.  Also, they require maintenance, as they of course have bearings, armatures, and in some case brushes.

-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)