| Author | Message | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 528 Registered: 3-2007 Posted From: 71.53.155.14  Rating: N/A |
I have an Onan 12.0 diesel. Model Is 12.0 MDJC-3CR/2268 T. Now,I am getting a little over 100 volts and I need to know what rpm to set the governor, Then where to set the voltage at[resistor] I don't know where it is to set either. Thanks I do have a manual but it doesnt tell all. gomer | ||
| wrench (Metricwrench)
Registered Member Username: Metricwrench Post Number: 26 Registered: 9-2006 Posted From: 76.101.105.177 Rating: N/A |
Normaly this should be a 1800 RPM, no load frequency at 60-61, voltage should be 120-125-VAC. wrench | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 1125 Registered: 12-2000 Posted From: 74.4.53.29  Rating: N/A |
I think that if you set the RPM to achieve 60-61 Hz, the voltage should be in the acceptable range (if there are no component problems) and the RPM will be close to 1800. Jack | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 878 Registered: 8-2006 Posted From: 64.55.111.6 Rating: N/A |
I think Jack's right, Wrench is too! Set the rpm for 1800, the voltage will be 120, and the frequency will be 60, trust the three of us. If you don't have a tach, set the governor for a no-load voltage of 120, and the speed and frequency will fall in line! Don't mess with the resistor, especially if it hasn't been messed with! If you have 1800 RPM, you WILL have 60 Hz, and you will have 120 Volts unless the resistor has been messed with. Changing speed changes the output voltage as well as the frequency, so it is not correct to adjust the resistor to increase the output voltage without knowing either the speed is exactly 1800 RPM, or the frequency is 60Hz. G | ||
| Dan West (Utahclaimjumper)
Registered Member Username: Utahclaimjumper Post Number: 190 Registered: 1-2005 Posted From: 208.66.38.60 Rating: N/A |
Marv, I just recently did this, check the voltage at an out let useing a simple VOM and adjust the speed to 120 volts, done deal.>>>Dan | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 529 Registered: 3-2007 Posted From: 71.53.155.14 Rating: N/A |
I just got back in from sweating most of my hair out and found; Gen running at 1500 rpm,adjusted to 1700{?} and it was only 110v. Readjusted to 1800 and that was still 110. Put one of two heat pumps on and dropped to 105v. Started sprinkling so I left it alone. Water and electricity don't mix very well. Will try again Monday and see what is up. Gomer | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 809 Registered: 7-2006 Posted From: 75.209.72.10 Rating: N/A |
Gomer....thanx for bringing this subject up...I am a bit gun shy about asking electrical questions, for reasons most of us on this board probably understand....   I have a 6.5 Onan...old one...runs well and seems to do it's job, but would like to "check it".. I note that at different altitudes, it runs differently, as most engines do....but is it putting out what it should at the rpms that should be? Ideas accepted....(no, I'm not an expert in electricity, no I don't know a lot about many things); yes, I understand English, yes, I understand safety, yes I have reasonable knowledge of electrical systems and yes I can take constructive criticism.....please... Thanx to all. RCB RCB | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 1126 Registered: 12-2000 Posted From: 74.4.53.29 Rating: N/A |
RCB, I purchased a small volt/frequency meter at Camping World that plugs into a standard outlet. I can plug it into the outlet I installed in the generator compartment and watch it as I adjust the generator or I can plug it into an outlet inside the bus to monitor generator output. Jack | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 882 Registered: 8-2006 Posted From: 64.55.111.6 Rating: N/A |
Gomer, One thought is for you to plug your meter into your house and read the voltage. I'm asking this for a check on your voltmeter. We don't know if your tach is correct either, so Jack's advice above is really good. Frequency and speed ALWAYS GO EXACTLY TOGETHER, you change the speed, the frequency will change, period. Proper voltage does need proper speed, but it can be adjusted AFTER the speed is right. Speed of AC motors is calculated by the formula: Hz X 120/ # of poles. Yours is a 4 pole, and we run on 60 HZ, so 7200/4=1800. So, a frequency meter will validate your tachometer reading, house (shore) power will validate your voltmeter, and might help you catch your tail instead of chasing it! I'm having a problem with 110 Volts at both 1700 and 1800 rpm, so please check to make sure you are running at exactly 1800 rpm, and tell us what the meter reads, in the bus, and on shore power! Chuck, A frequency meter is the quick way, set the speed for 60 Hz. A voltmeter is next best, set the speed to get 120 Volts with no load. Wouldn't hurt to check the meter on shore first either, it should read between 118-120 Volts. Unless there is a component failure, proper speed should produce proper voltage. G | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 884 Registered: 8-2006 Posted From: 64.55.111.6 Rating: N/A |
Gomer, You aren't using a "Wiggy" are you? (As you can see, its an hour and 15 minutes later, and I just thought of this.) It would explain the voltage problem... Stay dry, G | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 816 Registered: 7-2006 Posted From: 75.209.46.106 Rating: N/A |
Jack...I checked online re the volt/frequency meter at CW, but found only the cigarette lighter plug-in thing and another battery meter which had not much description to it. Possible to take a pic..or note a Model number? The others I have found on the web are pro devices George...any recommendations? Volt meters I got....frequency I don't got. Thanx. RCB | ||
| joe padberg (Joemc7ab)
Registered Member Username: Joemc7ab Post Number: 355 Registered: 6-2004 Posted From: 66.38.159.33 Rating: N/A |
Chuck The gadget being talked about 8 posts lower is the thinghy you are looking for (frequency meter) That along with a decent volt Ohm Meter is about all you will need. Off course things like DC and AC fundamentals you can learn here by just asking the questions. Joe. | ||
| Jim Gibson (River_rat)
Registered Member Username: River_rat Post Number: 112 Registered: 1-2009 Posted From: 75.95.96.192 Rating: N/A |
I just put a post last week on a genny setting tool. You can buy a device called a Kill A Watt for $20 bucks from several places (there is link on the other post) and this little device reads frequency. Just plug it into aan outlet and read frequency, then adjust your govenor to hit 60-61 hertz. Thats number one. Once you have that set, you are at 1800 rpm. If you are not getting 120V, there are a couple of pots on the regulator board that will set the 120V without changing the speed/frequency. You need 60 cycles, its pretty impostant. Thesr is a great forum that has some really good onan people - called SmokStak and they can be great at this stuff. Just went through it on my 7.5kw and that little meter was great, and it does a bunch of other stuff. Jim | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1638 Registered: 12-2000 Posted From: 76.69.141.254  Rating: N/A |
Here's the link: http://www.newegg.com/Product/Product.aspx?Item=N82E16882715001&Tpk=kill%20a%20watt I'll be ordering mine momentarily. happy coaching! buswarrior |