Go Back   iRV2 Forums > iRV2.com COMMUNITY FORUMS > Vintage RV's
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
 
Thread Tools Search this Thread Display Modes
 
Old 11-21-2012, 08:28 PM   #29
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by Dave78Chief View Post
Here is the troubleshooting manual for the "NP" series Generac generator:
http://gen-parts.com/Manuals/Y78800.pdf

Circuit diagram is on pdf page 41. Physical connection diagram is on pdf page 42. From what I see and what has been said, if all connections/wires are ok then like others have said, the voltage regulator is bad.

BTW - the high voltage is most likely overdriving the ATS sense circuit which is the source of the buzzing. You really need to disconnect the generator at the ATS switch until you get this voltage issue resolved. Wire in a light bulb to act as a load on the gen until fixed. The high voltage can damage other things like the MW, converter, ATS, etc.

Dave
Funny but that buzzing was never there until I found and repaired that remote gen start wire. I barely use the gen at all except to keep it working just in case I need it. I don't think it has run any more then 30 min since that buzzing started
__________________

__________________
Bilito is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 11-22-2012, 07:44 AM   #30
Senior Member
 
Dave78Chief's Avatar
 
Join Date: Jun 2009
Posts: 1,513
May be no way of to determine if that wire is associated or not from here. Looking at the drawng on pdf page 41, can you indicate which wire you repaired? The only thing besides the voltage regulator that I can think of that would cause the symptoms you have is if the start up boost current remained energized in the run mode. BTW, you can always unplug the remote panel to see if the problem disappears.

Dave
__________________

__________________
Dave in Virginia
1978 Winnebago Chieftain
Dodge M400 - 440-3
Classic Winnebago Site: http://www.classicwinnebagos.com/forum/index.php
Dave78Chief is offline   Reply With Quote
Old 11-22-2012, 08:03 AM   #31
Senior Member
 
Rick Long's Avatar
 
Fleetwood Owners Club
Solo Rvers Club
Join Date: Dec 2007
Location: Some Place
Posts: 1,161
Send a message via Yahoo to Rick Long
Voltage regulator in the generator. Look for a diagnostics page from your generator manufacture. If your's is an Onan, here is a good one...

Troubleshooting/Cross-Reference Guides | Flight Systems
__________________
1999 Fleetwood Bounder 32H
Many Places Full Time
No Dog * No Cat * No Co-Pilot
Rick Long is offline   Reply With Quote
Old 11-22-2012, 08:34 PM   #32
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by Dave78Chief View Post
May be no way of to determine if that wire is associated or not from here. Looking at the drawng on pdf page 41, can you indicate which wire you repaired? The only thing besides the voltage regulator that I can think of that would cause the symptoms you have is if the start up boost current remained energized in the run mode. BTW, you can always unplug the remote panel to see if the problem disappears.

Dave
It was the yellow wire which would be number two on the diagram
__________________
Bilito is offline   Reply With Quote
Old 11-22-2012, 08:45 PM   #33
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by Rick Long View Post
Voltage regulator in the generator. Look for a diagnostics page from your generator manufacture. If your's is an Onan, here is a good one...

Troubleshooting/Cross-Reference Guides | Flight Systems
Mine is a Generac and if anyone can find a source for me for one of those improved replacement VR at a reasonable cost and by reasonable I mean less then 125 buicks, I am running out of money.

Every time I fix one thing it seems to always lead to another and they are all 50 bucks here, 75 bucks there, and suddenly it adds up fast to thou.

My Generac VR part number is a 74074

I am tied up with a bathroom remodel at my sister in laws until Monday, but I will check here every night. The two new CB were around 40 bucks plus 5 bucks for a pack of shrink wrap connectors to make them work. I found this voltage problem after I changed the breakers.

You know that I have not checked to see what the DC voltage output is, guess that will have to wait until tuesday.

This Generac sure is fast starting, smooth running and fairly quiet unit.
__________________
Bilito is offline   Reply With Quote
Old 11-22-2012, 08:58 PM   #34
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by Dave78Chief View Post
Here is the troubleshooting manual for the "NP" series Generac generator:
http://gen-parts.com/Manuals/Y78800.pdf

Circuit diagram is on pdf page 41. Physical connection diagram is on pdf page 42. From what I see and what has been said, if all connections/wires are ok then like others have said, the voltage regulator is bad.

BTW - the high voltage is most likely overdriving the ATS sense circuit which is the source of the buzzing. You really need to disconnect the generator at the ATS switch until you get this voltage issue resolved. Wire in a light bulb to act as a load on the gen until fixed. The high voltage can damage other things like the MW, converter, ATS, etc.

Dave
Wow thanks for the trouble shooting manual
Got a question,
On test #28, it says to see fig 45 and test wires 11 and 22 for an open or shorted condition.
Please tell me exactly how I do that with my simple digital mutimeter.
Like which probe goes where and what should I see.
What does open look like and what does shorted look like when I am sticking my probes in there on a running unit or do you do it with the unit off.
__________________
Bilito is offline   Reply With Quote
Old 11-22-2012, 11:07 PM   #35
Senior Member
 
Ford Super Duty Owner
Join Date: Jan 2011
Location: Kitts Hill, OH
Posts: 1,863
I would check the volts with a decent load and see where you are. You might be surprised at what you might have.
__________________
(RVM#26) THE U-RV 94 F-700/24 foot U-haul box home built RV
Mekanic is offline   Reply With Quote
Old 11-23-2012, 06:51 AM   #36
Senior Member
 
clyon51's Avatar
 
Monaco Owners Club
Join Date: Mar 2012
Location: Arizona West RV Park, Yuma, Az
Posts: 4,116
Quote:
Originally Posted by Bilito View Post
Mine is a Generac and if anyone can find a source for me for one of those improved replacement VR at a reasonable cost and by reasonable I mean less then 125 buicks, I am running out of money.

My Generac VR part number is a 74074

Ok, here is one for $99. The original part # was 74074, later it was changed to 83048. The 83049 (below) is identical except it has cooling fins on the back and is a bit thicker. So you may need longer screws, probably worth it to save $50.

83049 Generac Regulator

This link is for the 83048, which shows it's the replacement for the 74074. I'm sure if you have any questions, these folks can fix you up.

Generac 83048 Voltage Regulator
__________________
John & Clare Lyon
2007 43.5' Monaco Dynasty Palace III (All Electric)
Towd: 2011 Chevy Equinox
clyon51 is online now   Reply With Quote
Old 11-23-2012, 04:59 PM   #37
Senior Member
 
Jim_HiTek's Avatar
 
Join Date: Nov 2011
Location: Full time RV'er
Posts: 1,656
Quote:
Originally Posted by Bilito View Post
Snip...

On test #28, it says to see fig 45 and test wires 11 and 22 for an open or shorted condition.
Please tell me exactly how I do that with my simple digital mutimeter.
Like which probe goes where and what should I see.
What does open look like and what does shorted look like when I am sticking my probes in there on a running unit or do you do it with the unit off.
A test for an open or short is done with the Ohms setting of your multimeter. There would be a notation of which color probe you use for with wire if there was polarization (like if there was a diode in there) in the manual. So, don't worry about probe color if there isn't.

Ohms (resistance) testing should be done with NO voltage on the wires so I always test with the voltmeter part first.
__________________
'02 Winnebago Journey DL, DSDP, 36' of fun.

Visit my RV Travel & Repair Blog at : http://chaos.goblinbox.com
Jim_HiTek is offline   Reply With Quote
Old 11-24-2012, 09:00 AM   #38
Senior Member
 
Dave78Chief's Avatar
 
Join Date: Jun 2009
Posts: 1,513
Quote:
On test #28, it says to see fig 45 and test wires 11 and 22 for an open or shorted condition.
Please tell me exactly how I do that with my simple digital mutimeter.
In this case you are trying to verify the stator sense wires, 11S a 22S on pdf page 42, are not open or shorted to something else (insulation rubbed off shorting them out). Given the number of wiring interconnection points, to do that with an ohm meter, you basically have to disconnect wires as described in Test 26.

In order to generate the rated amperage, this generator has to 2 power windings that are connected together in parallel at the CB1 (11 and 33) and at the ground point (22 and 44). The VR monitors the voltage acoss both windings via 11S and 22S (the 2 wires being checked in Test 28). It then adjusts the rotor field voltage (0 and 4) in order to maintain the adjusted output. For this unit, the VR is supposed to stop voltage generation if the output voltage exceeds 4% of the adjustment point. If adjusted for 124VAC, it will shutoff if voltage exceeds 129VAC. Appears something has gone bad in the VR such that it thinks 165VAC = say 120VAC.

Dave
__________________
Dave in Virginia
1978 Winnebago Chieftain
Dodge M400 - 440-3
Classic Winnebago Site: http://www.classicwinnebagos.com/forum/index.php
Dave78Chief is offline   Reply With Quote
Old 11-26-2012, 08:46 AM   #39
Junior Member
 
Join Date: Nov 2012
Posts: 19
Quote:
Originally Posted by Dave78Chief View Post
Appears something has gone bad in the VR such that it thinks 165VAC = say 120VAC.
The VR probably knows that 165V=165V, but it can't throttle down the output. This is a very common type of VR failure. There is an electronic switch in the VR (like a transistor, but probably an IGBT or MOSFET) and it has failed shorted, which is a very common failure mode. When the VR tries to "turn off" current to the exciter windings, it tells the electronic switch to open, but since it's shorted, nothing happens. Fixing the VR or replacing it are the only options.
__________________

__________________
Sportscoach is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 10:04 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.