PU-406/M searching for info and parts.

[Guus]

Hello i am new here i hope i am in the right thread.

I have a old generator ( PU-406/M ) without nametags or schematics.

The things i am searching for are :

- The technical manual TM5-6115-321-12
- All the schematics .
- What was the factory color ?
- Hydraulic governor parts .

I like to keep it as original as possible .

Thanks in advance.

 

[Guyfang]

Hello i am new here i hope i am in the right thread.

I have a old generator ( PU-406/M ) without nametags or schematics.

The things i am searching for are :

- The technical manual TM5-6115-321-12
- All the schematics .
- What was the factory color ?
- Hydraulic governor parts .

I like to keep it as original as possible .

Thanks in advance.

We need to start at the beginning here. A long time ago, there was a TM that covered the PU, (Power Units) and PP, (Power Plant) generator/Trailer set ups. I am guessing you checked TM 5-6115-365-13, for your set, PU-406-M. Much later the Army created the PU-406-B/M. Same set up, just newer gen set. So I will ask you, what is writen on the Gen set data plate? What model number, NSN for the gen set. Because the TM 5-6115-321-12 has been gone a LOOOOOOOOOOOG time. Some of these PU sets were modified without changing data plates. So look at the gen set first.

When these sets came out, they were OD Green.

Since you are asking about the Hyd governing system, this has to be a Precise Power set.

I may have the 321-12, have to look in my junk.

 

[Guyfang]

I do not have the TM for the origenal set. Will ask someone I know in CECOM if he may have it, but I would not bet money on it.

 

[Guus]

Acording to the data of Detroit Diesel the engine is from 1968

The problem is the data plate is missing .

 

[Guyfang]

can you post a few pictures?

 

[Guus]

Something like these ?

 

[Guyfang]

Baby, these pictures bring back a lot of old memories. Where did you get this set. Is it fitted with the hyd actuator? It looks like the 45 KW 52300, but could also be the 30 KW. They looked the same, and had the same control panel.

The AC volt regulator should be located in the upper left side of the control cube. The Over/ Under box, (over volt/under freq relay should be in the top, middle of he control cube. There were several safety relays in the cube also. The day tank was in the left rear of the set. The over speed switch, located at the rear of the engine. A real centrifugal switch. If you have time, some shots of inside. If it is indeed a 45 KW, I can, with maybe a schnapps or two, still remember where all the components are.

 

[Guus]

There is only one identification plate and this is it :


There is a switch named Emergency Switch what is it for ?
And there is a switch on the inside of the door of the control cube , what does it do there is no text next to it ?

 

[Guyfang]

The "Emergency Switch". The switch under the red switch guard. There are a few safety circuits in the set. When they turn on, you can not put out power, or keep the set running. They are there to protect the gen set from killing someone, or destroying itself. BUT, In a war time environment, sometimes safety takes second place to survival. If the gen set will not run, your Missile System will not function. If the missile system will not function, the bad guys will kill you. So the option is there to engage the emergency switch, and walk away for the gen set. It will run until it uses all its fuel, or destroys itself.

This is the 30 KW. I did not have a lot of experience with this model. But attached is your picture, with numbers written next to the sides.
1. Frequency Transducer. Converts 120 VAC signal to DC, and powers the Hertz Meter.
2.Safety relay. Not sure what.
3. LMU. Load Measuring Unit. Measures the load output, for Parallel operations.
4. This is probably a 500 Ohm resister, for the Air Box Solenoid circuit. When you shut the set off, the Air box should close up, and let no more air into the engine. It is also in the safety circuit. If a safety tells the gen set to shut down, then the Air box shuts off air and stops the engine.
5.The electric governor.
6. This is the AC Volt Regulator.
7. The black things on the box may be relays, or may be electrical tubes covered by aluminum tube covers. If so, this is part of the AC Volt Reg.
8. This is the Thermal Watt Converter. It collects AC signals, converts them to DC signals, to be read by the Percent of load meter and Power meter.

I can not see the switch you asked about, but most of the old sets had a manual excitation switch, to light off the main gen in case it did not happen automatically.

The two pots, (rheostats) on the left side could be to adjust the Over/Under box.

Since the numbers did not get copied, the #1 is the line that5 goes to the left. The #2 is the line in the bottom left corner. And so on, in a CCW fashion.

 

[Guus]

Thanks for the info , the only thing I figured out so far was the governor control.

On the outside of the control cube are 5 switches :

1- (S4) emergency switch , does not stay in one position (broken ?)
2- (S3) overvoltage relay reset .
3- (S6) paralel switch
4- (S9) electric governor .
5- (S8 ) flash field .

The switch i meant is S7 on this picture. ( center top )

 

[Guyfang]

This is just a guess, but it could be to switch from 50 to 60 hertz.

I have asked two old farts if hey may have this TM. Both said no, but would ask around. How about shots of the inside of the set, when the light is right. Please keep in mind, its been almost 47-48 years since I saw this set last.

 

[Guyfang]

I got about half a mind to get in my car and come visit. Its not far to you. But right now, that is not an option.

 

[Guus]

I am happy with all the information I can get about the generator.




I am trying to get the wire harness in order, someone has played with terminal blocks.......
There are no wires to the heater but the red light comes on when you switch on the heater .

 

[Guyfang]

Oil bath air filter. We always put used oil in it, because it was a waste of money to put new oil in it. Sometimes, like in summer, we had to use a putty knife to get the oil out. It was almost as hard as soft ice cream.

The battery charging generator, was a beast. Heavy, and a pain in the butt to replace. There should be a DC Volt Regulator someplace on the set also.

So far, no luck finding anyone with the TM's.

If you ever get the beast running, for goodness sake, ground it. And NEVER open the the right rear door when its running, unless you are REAL careful. All the things that will kill you, are behind that door.

 

[Guus]

My previous reaction has disappeared , strange ??

Again the same answer :

There is brand new oil in the air filter , done by the previous owner.

The voltage regulator is mounted on springs besides the oil drain.

The first thing i did was grounding the machine.....

All the things that will kill you, are behind that door

The thing that sounds like he wants to kill you is behind the front two doors....
It is a 3 cylinder but it sounds like a V12 And the acceleration is WOW

 

[Guyfang]

Yes, that baby can ROAR! When we sometimes were working on the Hyd. actuator, and had it disconnected, we kept a clip board handy, and took off the air intake hose. If the engine ran away, we slapped the clipboard onto the air intake to kill the engine.

 

[Guus]

On Saturday I let it run without switching on the generator section.

Manually keeping the speed right is quite difficult.
I have let it run for an hour to test the cooling system to see if it was leak-proof the thermostat in the bottom of the radiator was rusted through , i have made a plate to close the hole in the bottom of the radiator.
The louvres in front of the radiator are manual now .

After an hour the block was still lukewarm with the louvres closed.

Doesn't a Detroit give off that much heat?
I had it running between about half and three quarters of the throttle.

Yes, the neighbors love me

 

[pjwest03]

Diesels in general don't heat up unless they have good load on them or the cooling system is really bad. They like to work.

2 cycle Detroit's are one of the most efficient ways available to turn diesel fuel into noise. They always sound like they're running twice as fast as they really are. Cylinders are firing every stroke. I always thought Detroit powered items were the best choice for life after an apocalypse due to the basic simplicity. The parts interchange between different series engines and different cylinder counts is astounding compared to other manufactures. They are extremely modular as they scale up. With just a bit of care they can live a good long time.

 

[Guyfang]

On Saturday I let it run without switching on the generator section.

Manually keeping the speed right is quite difficult.
I have let it run for an hour to test the cooling system to see if it was leak-proof the thermostat in the bottom of the radiator was rusted through , i have made a plate to close the hole in the bottom of the radiator.
The louvres in front of the radiator are manual now .

After an hour the block was still lukewarm with the louvres closed.

Doesn't a Detroit give off that much heat?
I had it running between about half and three quarters of the throttle.

Yes, the neighbors love me

I always love to hear the Detroit Diesel run!!

How are you holding the RPM steady? Since this is precise set, you use the throttle cable to start it,but when the gov turns on, the Hyd Act takes over. If you are not using the Gov, simply lock down the throttle cable.

 

[Guus]

If you are not using the Gov, simply lock down the throttle cable.

I had disconnected the governor and kept the rpm by hand.
The Detroit slowly creeps up in speed even if the throttle stays in the same spot...