MEP -003 intermittent voltage on L1:L3 ....

[Kahles56]

I have intermittent voltage on 240 single phase voltage on L1:L0, I have full voltage on L3:L0, maybe a little over voltage , 138 volts.

On L1/L0 I will get a same reading as L3:L0 for about a 0.5 second them there is no reading at all I have jab quite hard on the posts to get voltage on L1:

Any ideas , I have not been to this site in over 5 years and threads are different , I remember something about this problem but no luck in search.

Any help appreciated .
Ken

 

[Mr4btTahoe]

I have intermittent voltage on 240 single phase voltage on L1:L0, I have full voltage on L3:L0, maybe a little over voltage , 138 volts.

On L1/L0 I will get a same reading as L3:L0 for about a 0.5 second them there is no reading at all I have jab quite hard on the posts to get voltage on L1:

Any ideas , I have not been to this site in over 5 years and threads are different , I remember something about this problem but no luck in search.

Any help appreciated .
Ken

Have you tried cleaning the posts with a small wire brush? Might just be corrosion considering you get a voltage reading if you jab the pose hard enough.

Sent from my SM-A515U using Tapatalk

 

[Chainbreaker]

As a troubleshooting starting point... with the generator shut down I would rotate the AC reconnection switch several times because the contacts can oxidize and not make reliable contact and you will not always get voltage output at load terminals. If you have not ever done this before just grab the switch and rock it back and forth until it breaks loose, you will feel a strong spring like action until it breaks free as you rock it left to right. If it won't turn don't go crazy and put vice grips on it as you run the risk of breaking it. If its stuck, you will have have to take the side panel off and just loosen the wafer switch nuts on the screws going through the wafer switch just enough to get it to break free. Then use contact cleaner sprayed on the contact arms between the wafers and work it back & forth several time to lubricate & clean contacts.

Also, while side panel is off do a visual inspection. I would put a screw driver on every wire terminal screw on the transformers & reactor just to make sure every wire termination is tight.

 

[Guyfang]

Total agree with Chainbreaker.

If that doesn't help. Pull the top cover. Measure from the OUTPUT side of the L1 terminal on the CB1 relay, to Ground/LO. see if it is a steady voltage. Then do the same thing to in INPUT side of the CB1. To make sure its not a K1 problem.

Also check that your L1 terminal is tight and or not damaged. The nuts are a very soft material. Often folks over tighten them. The threads strip out and the nuts do not make a good connection. Check the terminals from the CB1 input and out put also.

 

[Kahles56]

Total agree with Chainbreaker.

If that doesn't help. Pull the top cover. Measure from the OUTPUT side of the L1 terminal on the CB1 relay, to Ground/LO. see if it is a steady voltage. Then do the same thing to in INPUT side of the CB1. To make sure its not a K1 problem.

Also check that your L1 terminal is tight and or not damaged. The nuts are a very soft material. Often folks over tighten them. The threads strip out and the nuts do not make a good connection. Check the terminals from the CB1 input and out put also.

Just got home ,
tried to move the phase switch / (AC reconnection switch) locked up solid , I
will have to take off the cover and loosen the wafer switch nuts and spray as you stated.
Something to do tomorrow as I am running out of light this afternoon.

One thing at a time to get this back to running correctly.
I am doing the easy stuff first then go into the systems if easy does not work.

Just put new batteries in it as the old ones (5 Years) were on very last legs and would just turn over the starter after 24 hours of charge.

I was reading in the manual that if the voltage was off on L1:L0, L3:0 that the AC regulator might have to be replaced/repaired.

If I ever do so I will never Not do a monthly run on this machine.
To much can go wrong in to short of time.

Looks like this is going to be a couple of weeks project to get the genset right, I hope I will out pace the weather.
Never the less I need to do this as we loose electric more so in the summer than in the winter.

The good thing is it got me off my dead a$$ to get this ready for the ASK Kit that I have for it as well as building a trailer for it so I can move it when necessary.

I will keep all informed as to outcome on progress as it proceeds.

One other question, will PB-Blaster use on the wafer switch be a problem?




Thank you for your help

 

[Guyfang]

One step at a time. One step. you are on the right track.

 

[Chainbreaker]

...One other question, will PB-Blaster use on the wafer switch be a problem?

Thank you for your help

I would recommend using a product that is specifically designed for cleaning & lubricating electrical contacts. There is a product called "Deoxit" or the "CRC", both contact cleaners work well but I prefer Deoxit. You should be able to find one or the other at a Home Depot or order online if you can wait.

 

[Kahles56]

OK,
I have a (alz moment ) here on my part.
I was doing some more research and letting the cold and rain go away while waiting for the CRC to help loosen up the 3 phase switch.
While I was checking a couple of items with my meter inside the control box and I realized that I did not have the meter set on AC , but had left it on DC voltage when I was checking L3 /L0, L1/L0, L3/L1.

( Lessons Learned here for every one. )

So I started up the unit per manual , set the rpms set the phase switch on control box
checked all breakers, set the voltage and hertz and finally checked the output lugs for correct voltage .
Low and behold the voltage is on each lug as required at the required voltage.
# phase selector switch still will not move.
I will be checking load later this afternoon as soon as I clean up my load cell, an old air-handler with 5- 2/kw heaters with a squirrel cage blower.
If this unit will take/ give 10 Kw I will decide on removing Switch or leave well enough alone.

Not happy here having cried wolf here on the unit.

Never the less I thank you for all input in tracking the voltage problem down.

On second thought I think I will be going through the complete unit and making sure that the wiring is correct and clean and checking out that dam switch.

 

[Guyfang]

You would not be the first to do this. Aint gonna be the last. Lesson learned. And a cheap one at that!

 

[Chainbreaker]

...If I ever do so I will never Not do a monthly run on this machine.
To much can go wrong in to short of time...

I would recommend at a minimum to run your genset quarterly to keep the fuel flowing through the system so it does not gum up the works (Injection pump in particular). Also you want to give it a workout under a ~75% or better load for an hour or so to get it hot enough to drive out any critters and heat the oil up to drive off any moisture that collects within the engine.

I've been running my gensets every 90 days and that seems to be working out well. I do keep my gensets on battery maintainers. It's better to find out about a problem before an outage occurs than going out to fire it up during an outage in the dark and wondering why it won't start or produce power.

So, if you let is sit for too long... "too much can go wrong in too long a time"

 

[Kahles56]

Will do and have done today:
cleaned the filters out, got as much trash , rust etc. out as possible, ran some new fuel in the unit with biocide and cleaner,
and ran it over an hour to heat it up.
Results of initial shake out: all fuel lines weeping and hard as a rock, put a wrench on all fittings to see if loose . Fittings not loose.
So...... fuel lines shot. I really expected better than 30 years out of the hoses . (yea right)

Did some research on fuel lines based upon the 003 parts numbers.
Results: The fuel lines as specified per MIL Spec. (MIL-DTL-8795) are especially suited for medium pressure hydraulic fluids, engine oils, fuels and coolant fluids. Medium pressure hose is used for applications with operating pressures up to 3000 PSI, and having a temperature range of -65°F to +250°F. See MIL-DTL-8794 for specific temperature ranges. Medium pressure lines as specified are utilized in high vibration machines ( aircraft, generators , etc.)
This explains the cost associated with the fuel lines, they were specified for vibration not pressure. -5 lines are about $10-12/ft. not including the fittings which are ~ $10-13 per each, SOME companies charge in excess of $20 per each on fittings and do not carry all of the types that you may need.

I have found surplus hoses with fittings for the filters at $20 each which they state are used.
Based upon the companies that I researched I can build new MIL Spec hoses with new fittings for same cost or close to and they will not be hard as a rock.

I have not tried to dissemble the hoses that I have , the hoses appear to have reusable fittings. Can anyone concur on this observation from past experience. I do not want to ruin a fitting until I know what type it is. I will have to do more research on the fitting assembly, I think it requires a mandrel to put together and might require a mandrel to take apart.
If the fittings are in fact reusable then I am looking at just purchasing the hose , ~ $10/ft., maybe less as I do not have to have CERTIFIED paperwork which reduces the cost of the hose. So I would be looking at max $ 200 for new Mil Spec hosing including a new aux hose.

I have read on other posts that some persons have used a lesser grade hose and the grade hose has stood up fairly well. I just do not want to wake up with a deteriorated hose from vibration in the middle of the night , I would rather go back with new spec hosing.

Thoughts, flames , whatever .

 

[Guyfang]

Will do and have done today:
cleaned the filters out, got as much trash , rust etc. out as possible, ran some new fuel in the unit with biocide and cleaner,
and ran it over an hour to heat it up.
Results of initial shake out: all fuel lines weeping and hard as a rock, put a wrench on all fittings to see if loose . Fittings not loose.
So...... fuel lines shot. I really expected better than 30 years out of the hoses . (yea right)
Yea right!

Did some research on fuel lines based upon the 003 parts numbers.
Results: The fuel lines as specified per MIL Spec. (MIL-DTL-8795) are especially suited for medium pressure hydraulic fluids, engine oils, fuels and coolant fluids. Medium pressure hose is used for applications with operating pressures up to 3000 PSI, and having a temperature range of -65°F to +250°F. See MIL-DTL-8794 for specific temperature ranges. Medium pressure lines as specified are utilized in high vibration machines ( aircraft, generators , etc.)
This explains the cost associated with the fuel lines, they were specified for vibration not pressure. -5 lines are about $10-12/ft. not including the fittings which are ~ $10-13 per each, SOME companies charge in excess of $20 per each on fittings and do not carry all of the types that you may need. (What we did is about what you propose. We always took a Aux fuel line, and cut it up, to make new lines if we could not order new ones.)

I have found surplus hoses with fittings for the filters at $20 each which they state are used.
Based upon the companies that I researched I can build new MIL Spec hoses with new fittings for same cost or close to and they will not be hard as a rock.

I have not tried to dissemble the hoses that I have , the hoses appear to have reusable fittings. Can anyone concur on this observation from past experience. (Indeed, the fittings are reusable. We at first did not have a mandrel, so we just took a fuel line adapter, screwed it in, and cranked on it. Then the fittings screw right out. Put them in the same way.) I do not want to ruin a fitting until I know what type it is. I will have to do more research on the fitting assembly, I think it requires a mandrel to put together and might require a mandrel to take apart.
If the fittings are in fact reusable then I am looking at just purchasing the hose , ~ $10/ft., maybe less as I do not have to have CERTIFIED paperwork which reduces the cost of the hose. So I would be looking at max $ 200 for new Mil Spec hosing including a new aux hose.

I have read on other posts that some persons have used a lesser grade hose and the grade hose has stood up fairly well. I just do not want to wake up with a deteriorated hose from vibration in the middle of the night , I would rather go back with new spec hosing.

Fitting, Hose NSN: 4730-00-842-2201 Part # MS24587-5

Tech data below

	THREAD CLASS	3B 1ST END
	MAXIMUM OPERATING TEMP	200 DEG FAHRENHEIT SINGLE RESPONSE
	END ITEM IDENTIFICATION	GRUMMAN A-10 ACFT
	CONNECTION STYLE	GRIPPING NIPPLE (NOSE) 2ND END
	CONNECTION STYLE	SWIVEL NUT, FLARE (TUBE) STYLE 3 OPTIONAL END 1ST END
	CONNECTION TYPE	THREADED EXTERNAL HOSE GRIPPING 2ND END
	CONNECTION TYPE	THREADED INTERNAL TUBE 1ST END
	MAXIMUM OPERATING PRESSURE	3000 POUNDS PER SQUARE INCH SINGLE RESPONSE
	NOMINAL THREAD SIZE	0 1/2 INCHES 1ST END
	SEAT ANGLE	37 DEGREES 1ST END
	NOMINAL INSIDE DIAMETER HOSE ACCOMMODATED	0 1/4 INCHES 2ND END
	NOMINAL OUTSIDE DIAMETER HOSE ACCOMMODATED	0 29/50 INCHES 2ND END
	NOMINAL OUTSIDE DIAMETER TUBE ACCOMMODATED	0 39/125 INCHES 1ST END
	NOMINAL OVERALL LENGTH	1 24/25 INCHES
	MATERIAL	ALUMINUM SOCKET
	MATERIAL	STEEL NIPPLE
	MATERIAL	STEEL NUT
	PROPRIETARY CHARACTERISTICS	PACS
	SURFACE TREATMENT	CADMIUM OVERALL
	THREAD SERIES DESIGNATOR	UNJF 1ST END
	FURNISHED ITEMS AND QUANTITY	1 HOSE COUPLING NUT
	SPECIFICATION/STANDARD DATA	96906-MS24587 GOVERNMENT STANDARD

There are 3 alternate NSN's and 21 alternate part numbers if you want to know them, I will look them up. There are 12 each of these fitting on the set.

Thoughts, flames , whatever .

Open to see comments and data.

 

[Kahles56]

Open to see comments and data.

Guyfang, Thanks for the reply on my questions pertaining to fuel hosing.
I am glad I was on the right track pertaining to replacement of the old hose and rebuilding the old fittings.

I have read many of your old posts dating back 5-6 years and always find a little something that I can use and utilize on these old pieces of American iron.
also I am very happy that I gave you a good laugh , laughing is good for all of us.

Ken

 

[Guyfang]

We all need to laugh a little bit more right now.

 

[Kahles56]

Well,
I have finally taken some time to work on the MEP- 003 3 phase /single phase 120 switch/220 switch.
Pulled the control box today so I did not /do not have to stand on my head to take the switch out of the control box.
It took me about 1/2 hour to disconnect and remove the bolts and remove the console.
It took 2 hours to take pictures of the wires connected to the switch and label them to get them back into the right position as well as shifting the switch around so get it out of the console, an extra 1/4 in of room would have made what looked like a easy project into an easy project.

I got the switch out. Pictures will follow at later time If any one is thinking about doing this.
Anyhow , this is what I have discovered.

A. there is a spring on the inside of the cover plate which sticks due to corrosion just behind the cover plate
B. all of the contactors are sticky and grimy due to age and need to be cleaned
C. this switch requires time to take apart as well as numerous pictures to assure correct assembly.
D. do not do this with children or tv or wife around as you need to take many pictures and notes on paper to assure reassembly.


This is a very complicated switch but still easy enough to clean /repair for the average person if notes and pictures are taken.
Notes below represent what I did today with the switch for the day and general notes for the day.
I plan to continue tomorrow and write up where I am at with the switch at end of day.

Notes: for taking switch out, read completely before starting and follow as you are working on switch.
1. mark top side of switch and make note of switch position
2. remove the Bakeolite nob,
3. remove small cross pin that fits in the inside of the nob that is pinned to the metal shaft, you may have to break the cross pin and nock out remainder after you get the switch out.
4. remove 4 bolts from front side of switch on cabinet
5. remove 2 bolts from back of switch on back of cabinet
6. get a hollow ground screwdriver to remove screws from switch, you might need small wrenches , it depends on which you have
7. now take as many pictures as necessary to remember how the switch is wired, remove wires from switch remove switch from cabinet.
This is a good time to drive or drill out the remainder of the cross pin.
8. With switch standing vertical remove the 2 nuts holding the top part of the switch together
9. Pop the cover off holding the nob shaft with a vice grip locked on shaft and up tight to cover plate, this will help you to take pictures of underside of cover plate for correct location of the rotating device and for pictures.
10. remove cover plate-( Be careful of cover plate as it has a dielectric wafer you do not want to brake.)
11. Clean cover plate and spring assembly with contact cleaner- do not take spring assembly apart as I do not know if it can be taken apart
12. Grease spring and cover plate with dielectric grease. place off to side
13. remove small sliding washer from center of switch which is actually a lock to lock position of switch- take pictures before removing
14. remove 2 nuts on the side shafts,
15. remove 2 spacers

to be continued........

 

[dependable]

I'd never advise taking switch apart or un doing wires. If you do, and get it back together, your a more patient man than me. As stated above, switch can be freed up just by loosening plate, not removing.

As also previously stated, good to check tightness of all the screws attaching wires.

I bought a 003 once with a recently replaced connector switch, work apparently done at depot. They did not even get it right, after many a frustrating hour, ended up finding a good used recconection box to get unit working.

Unless an ASK equipped unit, I find taking fuel tank off and removing side panel is a little easier than removing recconection box. Probably need to clean the tank anyway.

As to original problem, it is also good to check cannon plugs are tight. I wish you luck and patience in reassembly.

 

[Guyfang]

Why mark the wires? There is a wonderful wire diagram in the -34 TM. Clearly shows what wire goes where, for what switch. As there are two different types of the switch.

 

[Kahles56]

To all,
I Just spent 6 hours taking a switch apart and putting it back together again.
I must tell you that the switch is a very well thought out device which commands respect to the designer of record.

that said I must modify my notes that I posted last night.

Alpha Notes
E. Before you think about doing this , Drink a 5th of JD or whatever suits your taste
F. After recovery from the 5th , drink another 5th.

Numeric notes:
13.a Do not try to move u-bracket which is encapculated buy standoffat this time
13b. spray whole switch with contact cleaner
13c. note direction u bracket is in , take picture
13d.
after cleaning take a 1.5 in or so 1/4 in extensionand place crosswise on U Bracket
13.c mark one side of u-bracket so you know absolute location in relation th the outside long posts studs .
13d. take a vice grip and clamp to 1/4 In extension and turn 90 degrees one way then back to original location, now do same thing except other way and back .If the u- Bracket will not move go to next step.
13e. losen the nuts on side shafts about 2-3 turns no more .
13f. take softblow hammer and tap switch to lossen wafers
13g. spray switch with cleaner between wafers
13h. retighten nuts
13I go back and do 13c. and 13d.
13j. if switch turns loosen nuts again and spray with electrical lub.
13k. retighen nuts
13L. replace the lock device , wafer and spring back on switch and try to move switch by taking a pare og vicegrips and some leather to protect the shaft. remember the switch only has 3 positions and only rotates 180 degrees.


Guyfang,
my hat is off in respect to you for working on these generators for these many years and keeping them running for the safety of the country.

I should have taken to heart what you said about this switch. it is not really designed to be taken apart and cleaned . Replaced yes not cleaned.

To all,
pictures will be forth coming later this week or next of the procedures 1-13L.

1-13L should take care of a majority of all the switches out there.

Removal of the switch allows one to change out the 120 volt plug very easily, remove and replace rusted screws and nuts and clean the interior of debris with a air hose as well as turn a screw an every electrical connector .

I will not post the teardown of the switch past 13L due to the complexity, I had another switch that I tore down and put back together as practice to find what could and could not be accomplished, the internals of the switch are many and you almost need a fixture to accomplish the procedure.
You need a sheet of plywood and a bead sheet to cover ply as the parts cover a 4x8 peace of plywood when broken down.

 

[Guyfang]

Yes sir! Man, I would rather clean an outhouse then take that baby apart. And I love puzzles. Good job!!

After I retired from the Army, I went to trade school here to become an electrician. We had a school field trip to a BOSCH factory. We visited a shop where they assembled switches like that one. And a shop that wound electric motors. The first thing you notice, is no men. Hundreds of lady's, but not one man. The guy who was showing us around, told us that the reason for that is men do NOT have the concentration to do that kind of job 8 hours a day.

 

[Kahles56]

Guyfang,
I want to confirm something with you on this switch

-34, Pg. 6-16, Change 7, Table 6-5 ,
shows the switch, when in position 2 , the first layer of contacts all have continuity with each other , if one contact does not have or show continuity with the other two contacts , then the switch has rotated to far in rotation or a contact may be burned.
So taking it one step further , if one rotated the switch to the correct position so the first layer of contacts have continuity with each other then one could select position 2 and check all layers for continuity on the contacts layer by layer?
Then do position 1 and then do position 3 to check for burned or non continuity where each layer shows 2 or more x's

Am I correct in my read of table 6-5?