PU 802

[Towbarman]

I have a PU 802 generator. Looking for the 2 wires off the voltage regulator to use to magnetism the exciter. The interrupter does not stay on when you hit the switch. The needle moves just a little when the master switch is turned to run for 2-3 seconds and the interrupter little goes out when you switch it up and down

 

[Ray70]

If you go up to the top of the page and go into the TM tab, scroll to the generator section and get the TM for an MEP-804A , the schematic will show you which wires you are asking for.
I wouldn't use the PU-802 reference to find info on the generator itself, go with MEP-804A ( I assume you have a trailer mounted 15Kw 804A?)

 

[Towbarman]

Ray70
Yes it is trailer mounted. Yes looking through the PU 802 reference really sucks. I've been working on this thing for a while now. Almost 70 hrs. Boss ain't happen. Thanks again. Towbarman Out.

 

[Guyfang]

I have a PU 802 generator. Looking for the 2 wires off the voltage regulator to use to magnetism the exciter. The interrupter does not stay on when you hit the switch. The needle moves just a little when the master switch is turned to run for 2-3 seconds and the interrupter little goes out when you switch it up and down

1. No you do not have a PU802 Generator set. You have a:
2 ½ TON TRAILER MOUNTED, 15 kW, 50/60 Hz
PU-802 (NSN: 6115-01-317-213 (EIC: N/A)
PU-802A (NSN: 6115-01-565-1576) (EIC: N/A)

2. PU means Power Unit. A power unit is a combination of a trailer and a generator set.

3. You need to tell us if its a MEP-804A or an MEP-804B model. The TM#s for both can be found here:

Generator and Electrical TM's

Find TM's for MEP and other generators in this forum. MEP-002A, MEP-003A, exc. - No posting of threads

www.steelsoldiers.com

I have a PU 802 generator. Looking for the 2 wires off the voltage regulator to use to magnetism the exciter. The interrupter does not stay on when you hit the switch. The needle moves just a little when the master switch is turned to run for 2-3 seconds and the interrupter little goes out when you switch it up and down

1. Is the Quad Mod installed on this gen set? See picture below, (Fuse Mod 804A) and if it has the Mod, is the fuse good.

2. You need to give us a bit more info. The main gen gets its initial Excitation from S1. Are you getting initial excitation?

3. By interrupter you mean S5, AC interrupter switch? What needle are you talking about?

4. By Master switch, do you mean the S1? The rest of the comment is, kinda hard to follow. Please describe it better.

 

[Towbarman]

Guyfang
I was looking at my work order and it states that it is a PU802. That's what's on the data plate also, but on the Generator it self does show it as a MEP804B.
It does have the new Quad Mod. installed. The fuse is good, replaced it with another that I did check twice. The test I was going to do to check the excitor was taking the F- and the F+ wires, touch them to my jumper wires that is clamp to a separate 12 battery. Touch them for about 10-12 seconds to magnetize the exciter. The interrupter is the S5, AC interrupter switch. The needle is from the Frequency meter. That moves a tiny bit when the S1 master switch is turned to run position and held it for 2 seconds. Once release the needle goes to 0. The interrupter light does not stay on when the toggle switch is pushed up. Once you push it upwards you see the light and once release it goes out/off. I was to the point that my issue is the voltage regular, which was replaces earlier in the service.

 

[Guyfang]

We are both right. The trailer and gen set are a PU set. But the MEP-804A is the problem. Most folks in the Forum are not familiar with the PU-802.

Below are the schematics. In the norm, even if the A5 is dead, the initial excitation comes from the S1 switch. On start up, you do need to hold S1 up longer then normal to get the exciter to light off. Often folks do not hold the S1 up long enough. And if you continue to hold the S1 up for say 20 seconds, the main gen should light off. Even with a bad A5. Because the S1 provides the 24 VDC to the exciter. When you let go the S1, the AC voltage falls off.

Dont worry about the S5 and the output yet. First find out if the set will make voltage.