MEP 804A questions

Thanks guys. I think I am going to have to get one to work with and figure it out. If it won't make voltage to run the pump without problems, I will have to find a transformer. I know an electric motor shop guy who says he can help me with that if I need to go that way. Mike

I dont know where in New Mexico you are, but there is one in AZ listed in the classifieds.

https://www.steelsoldiers.com/showthread.php?186812-MEP-805B-on-M200A1-trailer

Finally found a low-time 804b. Runs fine, makes power. I am still trying to figure out the voltage output. I have moved the terminal board to the 208-416 setting. With the voltage knob turned all the way up, I am getting 409 volts. From what I have learned here and from GMG specs for this generator the possible voltage range is 395-480 volts. I think I need at least 465-470 to run my pump motor. There is a voltage range adjustment on the voltage regulator behind the control panel but it looks like it has been painted to lock the adjustment. Can I use this to adjust the voltage to get into the range I need without causing problems somewhere, and if so, how? Mike

Remember please, on this unit there is an INTERIOR voltage decision that has to be made as well the link board, when I say interior, I am directing you to the control box settings inside/behind the fold down front display panel, this ALSO has to be set to the higher range voltage for everything to sync up. This should solve your voltage issues.

Caution please don't get hung up on rather or not your making 460 or 480 your pump will not care .. the neutral voltage will be 265/277 respectively to 460/480 or the Square root of of 3 divided into your 460/480 or whatever your line to line voltage turns out to be, this is where you see the 240/416 combination so often shown. NOTE: 240 is not a sum of 120 and 120 single phase as it is sometimes proffered.

In 3 phase voltage situations the Sq of 3 is 1.732 [rounded] this is why the sum of the 120 voltages make it 208 line to line and not 240. The caution here in this sequence if you turn up your L-L voltage to reach 240 you are also making near 138 neutral voltage and your 120 equipment will very likely go "poof" and all the smoke comes out of all your crap that is plugged in... let us know please ?? BEST: mac/mc

Thanks mac/mc. This well is in a remote location and is the only need for power. I don't have to worry about burning anything else up with L-N voltage. After reading the motor manual again, it says that voltage at the motor needs to be within 10% of nameplate voltage at the pump. Even considering voltage loss in 1,000' of 10ga pump cable I could probably get by with something less than 460v. But if I decrease the voltage I may increase the amperage too much which might not be good for the motor.

I thought there should be a way to increase the generator voltage. From what you are telling me, the voltage range adjustment on the regulator should do it. But when I looked behind the control panel I got intimidated by how much is back there and how complicated it looks. The voltage range adjustment is a fragile looking thing and it looks like it has been sealed to keep somebody like me from messing with it. I will give it a try. Thanks again, Mike

Tweaked the voltage range adjustment maybe 1/8 turn. Now the voltage can be adjusted to at least 480. Hooked up an old 5hp motor with no load on it, everything seems fine. Will try to pull it up to the well tomorrow. By the way, as mac/mc warned, the single phase voltages are not usable. The convenience receptacle measures 138v at 465v L-L. Thanks to everyone who has posted to this thread to help me out. After we use it to pump for a while I should have some figures on fuel consumption. Thanks again. Mike

FYI for anybody interested-We have about 40 hrs. on the machine now. 464-465 volts, 5 hp 3 phase pump draws 7.8 amps. Load meter shows 40%. Fuel consumption is around 0.7 gallons/hour maybe a little less. Generator is lightly loaded, you can barely notice when the pump starts. Elevation is about 5200'. Don't know if that makes a difference in fuel consumption on a turbocharged engine or not. So far the 804b is great solution to our problem. Mike

These new electronic controlled genny's, you dont hardly notice the change of load..ever. Even going for 0 load to 33kw on a 30kw was just an ever so subtle change of tone. You will be very happy.

Mike I will scatter shoot here, first to the applicability of an 804A/B. either will work just fine for your needs. In reality the 803 would work well also. The 803 will make 480 Volts just fine, but near if not ALL the logic will need to be redone or made to work with the 480 output.. That effort in its self V. using the 804 may lend you to using the 804, don't give the "Stby" any thought, your application is fine and will only need fuel and normal servicing issues. The Voltage regulator will work as it is , but the "RANGE" will need to be increased to take it beyond the normal settings for 416 +/- up into the 480 area will however need the broader increase so you can focus on the 460-480 desired voltage.. we do it all the time not a problem..Again I wouldn't dismiss the 803 but with the knowledge it will take some work effort to get it into the 480 area. Again I know from experience this can be done as I built up a unit for our City here locally to run the sewer lift station it just comes down to your comfort level and no rocket Science is needed..
If i can help you i will try and be more responsive to your questions or needs .. As a broad overview for the 803 at 480 we just gutted the controls in total, and went with a whole new package featuring remote and full Auto Start, way more details than the general readers/users might care to read or find out about..
Regards: mac/mc

Mac, his post was 2019. But still good to see you are alive and kickin!!

Happens to me all the time!

I was going to start another thread with this post but since this one has been revived I will put it here. First, thanks for the responses and the help. Our 804B has been working great for our application. The radiator developed a small leak at the seam where the tank is soldered to the core. My radiator repair guy told me it looked like excess pressure caused the leak and I should check the thermostat. I decided to replace the thermostat as a precaution. I needed it in a hurry so I didn't want to order online. Our local green John Deere dealer had the thermostat and the gaskets in stock. The John Deere part no for the thermostat is M811034 and the parts guy crossed it from the Yanmar no. that I found in the technical manual here. Deere uses Yanmar engines in a lot of their smaller equipment. The price wasn't even too bad. Most of you probably already knew about John Deere as a source for these engine parts but it was new to me.