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Onan Err 27 PMA Sense Lost

Yahoo Message Number: 97363
Hi - Just thought I'd put this out under another subject so it's easy for folks to read what the problem is. Genset starts then dies about 5 seconds later and blinks out error code 27. PMA sense lost. Unable to sense PMA frequency. Any suggestions would be greatly appreciated. Thanks.
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Best - Scott

2006 Allure 430 40' #31349

(Bus-Stead Lemon) My Allure Page http://www.muniac.com/Allure%20Page.html

Re: Onan Err 27 PMA Sense Lost

Reply #1 –
Yahoo Message Number: 97364
Sounds like either the gen isnt producing power or it isn't able to sense the frequency of the voltage .

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"Scott scott@... [Country-Coach-Owners]" wrote:

Hi - Just thought I'd put this out under another subject so it's easy for folks to read what the problem is. Genset starts then dies about 5 seconds later and blinks out error code 27. PMA sense lost. Unable to sense PMA frequency. Any suggestions would be greatly appreciated. Thanks.
--

Best - Scott

2006 Allure 430 40' #31349

(Bus-Stead Lemon) My Allure Page http://www.muniac.com/Allure%20Page.html

Re: Onan Err 27 PMA Sense Lost

Reply #2 –
Yahoo Message Number: 97400
Scott,

I had about the same identical problem you had at 2000 hours on my 12.5KW QD.

Seemed simple at first. Onan manual says: code 27

inverter lost PMA sensing

1 check wires between stator and inverter for loose or bad connection

2 ohm stator there are 3 pairs of wires check t1-1 and t2-1
t2-1 and t3-1
t1-1 and t3-1
t2-2 and t1-2
t3-2 and t2-2
t1-2 and t2-3

.997-1.219 ohms at 70*

if winding open replace stator

3 replace control board

Only 2 things can be bad. Control board or the stator.
EXCEPT, if the bearing at the stator has gone bad, and the shaft turns out of round, scores the stator wiring, and causes an intermittent symptoms while trouble shooting.
Finally just pulled the housing apart, pulled the stator, which had a few scored windings, and a frozen end bearing.

Replaced stator, end bearing and was good to go.
Called ONAN and they recommend checking the bearing play every 2 - 3 years. No way to lube it, just have to replace it if crummy.

Luck,
Bob

Re: Onan Err 27 PMA Sense Lost

Reply #3 –
Yahoo Message Number: 97401
Is the gen connected to silverleaf? I had problems on my 08 and I shut the chassis switch off and forced silverleaf to re-boot. problem solved. Not sure on an 06 but figured I would throw out the suggestion. It may help someone someday

Re: Onan Err 27 PMA Sense Lost

Reply #4 –
Yahoo Message Number: 97415
Bob - My inverter/converter assembly was shot. I did the repairs myself and am now back on-line. When the write-up is done, I'll post the link to it. Tough repair!

Best - Scott

2006 Allure 430 40' #31349

(Bus-Stead Lemon) My Allure Page http://www.muniac.com/Allure%20Page.html

Re: Onan Err 27 PMA Sense Lost

Reply #5 –
Yahoo Message Number: 97417
Scott,

Cool, I can relate to the tough part. I got so fed up with spending time on the phone with Onan. The parts guys kept sending me new boards to plug in, and replace what they thought were factory defective replacement parts.
Any how, I used a fork lift to remove the gen set completely, and just tore down the stator housing until I could at last see the problem. I let Onan know, and they said "Oh yeah, that happens sometimes. The end bearing goes bad and creates an intermittent fault. Wish they had mentioned that a week earlier.

Glad yours was less annoying. I look forward to seeing the write up on line.

Luck,
Bob

Re: Onan Err 27 PMA Sense Lost

Reply #6 –
Yahoo Message Number: 97440
Bob - Service and support is everything which is rapidly becoming a lost art in today's times. My chronicle is here: http://www.muniac.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=547#Post547 Even the fellows down at Engines, Inc. have expressed some frustration dealing with Onan. The one fellow I dealt with goes all the way back to when Onan was a stand alone company. A lot has changed since then.
Many of the old schoolers have moved on leaving their jobs to younger less experienced people with much less depth. Many of those youngsters haven't had a dab of grease on their hands of know anything about a field service situation. If the situation isn't found on their computer prompter, they are lost.

Your genset must be slightly different than my smaller 8K unit. On my unit, the bearing that supports the rotor is the rear main bearing of the engine. The last small item I need to fix is the hours meter. I just noticed it isn't ticking off run time. There's always something I guess.

Best - Scott

2006 Allure 430 40' #31349

(Bus-Stead Lemon) My Allure Page http://www.muniac.com/Allure%20Page.html