Needing a starter switch for MEP 805A

[Bplas]

Hello,
im looking for a start switch for a MEP 805A and I’m assuming that it’s bad because when returned to run the low voltage light comes on but not if held in the start position.

 

[Guyfang]

Wrong.

1. Do you have the quad circuit MWO on your set?
2. If you have the MWO, have you tested FU-2?
3. Did you hold the S1 switch in the start position long enough?
4. If you have the MWO, and the fuse is good, and you held the S1 up long enough, then perhaps your A1 is bad?

 

[Bplas]

Thanks,
the fuse was blown, I will have to do a load check tomorrow but everything is working as it should be for now.
should I be concerned about the fuse being blown? If so what thoughts do you have as to why?
the unit has 27 hours on it since complete overhaul in 2011.
thanks again
bplas

 

[Guyfang]

I hope you did not simply jump the fuse and try testing the gen set. Buy several fuses, in case you need them for trouble shooting. The fuse is there in case the A1 ( AC volt regulator) is bad, in the over volt way. So yes, it could be a problem. FIRST get a new fuse to put in it, THEN try it out.

 

[Bplas]

Well maybe 20 years ago I might have tried to jump the fuse but I’m WAY past that point in my life, do it right the first time or don’t do it at all because it will surely come back to bite me in the butt. I’m going to put it under a 65-75% load later today and see what happens but if the fuse blows we will test the regulator to see if it works but the TM doesn’t show where line 137 is so I’m going to have to find a schematic. I know it’s on k3 over/underload relay.

 

[Guyfang]

Well maybe 20 years ago I might have tried to jump the fuse but I’m WAY past that point in my life, do it right the first time or don’t do it at all because it will surely come back to bite me in the butt. I’m going to put it under a 65-75% load later today and see what happens but if the fuse blows we will test the regulator to see if it works but the TM doesn’t show where line 137 is so I’m going to have to find a schematic. I know it’s on k3 over/underload relay.

First the fuse. Then start it with no load. Run it a few hours with no load, just to see if it will run a while, and to check for leaks. What is "line 137"? Dont worry about load till we see if its a runner.

 

[Bplas]

Ok, I ran her for 2+ hours yesterday without a load and everything was fine she purred like a kitten but my gut tells me that once we put it under a load that the fuse will blow.
the wire I was talking about was from the TM on how to check the under/over voltage relay, it is wire 137a and 141a on the voltage regulator and after I reread the TM instructions it made sense but I haven’t done the test.
so what would you like to have me do next?

 

[Guyfang]

Put it on load. The amount of load can not influence the A1 in this respect. The FU-2 fuse would have blown on start up if the A1 had a problem. The K5, (over volt, under volt) relay can not be your problem, fuse wise. So simply put it on load and give it a try. What type load are you thinking of using? Keep in mind, the 120 volt outlet is not advisable for load testing.

 

[Bplas]

I was going to put a 3 phase 5.5 ton AC unit that has a 35,000 or a 55,000 btu heater built into it.
in my life what works one day won’t the next so I will go out and start it again this morning and see if it blows the fuse today and if not then we will hook up the AC unit and put it under the load test. I will let you know how it goes.

 

[Bplas]

Well I apparently need A1, as soon as I let off the switch the under voltage light came on, bummer, but at least with your help we found the problem, thanks guyfang!
where can I find one of these rascals?

 

[Guyfang]

Stop. The light came on, did the voltage drop off, on the AC volt meter? If there is still AC volts on the meter, then it could be a relay, or even the A2, (fault indicator).

EDIT. No I am tripping. If the fuse blows, it has to be the A1.

EDIT-2. I read the post again. Check if the fuse is blown. Then we can take another step.

 

[Bplas]

GF, were both tripping if that helps, I went out and started it again and the light was on so I shut it off and removed the fuse and checked it and it was fine so I reinstalled it and started it again and this time it worked fine so I shut it off and then started again and it was fine so I did it three more times and it was fine, who’s on drugs, I’m going to go back out and try it again and if it works fine I will put it under a load test and see what happens. Welcome to my life GF, I will keep you posted.

 

[Guyfang]

What's important here is that the fuse didn't blow. See if you can repeat the fault. Then notice what happens. IF, the the fault happens again, look at the volt meter to see if you lose AC volts. If the fault reoccurs, and the vot meter reads the right AC voltage, then problem is not the fuse, not the A1. It has to be a relay, or the fault indicator.

 

[Bplas]

Ok, well will see what happens if and when it occurs again and look at the voltage to see if I has remained the same.
i went out and put it under a load test and it didn’t have any problem but it was only a 25-30% load so tomorrow I will try to load it up as much as I can and then see what happens if anything. Right now it didn’t even change RPM’s so it wasn’t much of a load. There is a problem with The hertz gauge and it doesn’t register properly so I’m not sure how close to I am to 60htz but for now let’s hope I’m reasonably close. We will wait and see what tomorrow brings us. Thanks again for your help so far GF.

 

[Guyfang]

Describe "dosnt register properly" for the hertz meter. Do you have a multi meter? If it dosnt have a frequency mode, you might need to get one.

 

[155mm]

I use an external voltage hz gauge as a backup that i plug in to convenience plug. Its not precise, but works to verify



AC Multimeter 6in1 Combo Meter Voltage 110V 220V Current 100A Power Factor KWH Frequency Multifuction Tester https://www.amazon.com/dp/B01LXY6GT5/ref=cm_sw_r_cp_tai_qeu1DbNCQ1KVQ

 

[Bplas]

The gauge has moisture in it and the needle goes to the 11o’clock position and stops (hangs up), hadn’t even crossed my mind about using the multimeter, thanks. (Chemo brain).
i think I will try that and put both of the AC units on the generator and see how it handles the load today as long as I can get it set up at 60 hertz.

 

[Bplas]

155mm, Would you be able to put the wire directly to the gauge to get the Hz?

 

[155mm]

I wouldnt,, i would use conv plug, or load lugs. I prefer conv plug, it has juice all the time

 

[Bplas]

Ok, great. Thanks.