MEP-003a No voltage

[juddspaintballs]

I started and ran several times today. No voltage and frequency drops off shortly after starting (and flashing). Over 300v if terminal 17 is off of the VR. Are we thinking bad VR now?

 

[jamawieb]

Sounds like the VR to me.

 

[Chainbreaker]

Ref Post 52:

...I went on to test the VR with terminal 17 disconnected. I suddenly had 175v AC at the convenience outlet and the AC voltmeter on the generator read nearly 300v. So, I put the terminal back in place and started the generator again. 240v AC on the generator's voltmeter, 120v AC at the convenience outlet, and 120v on both L1 and L2 when read against L0. 60.05 Hz on the Fluke and in the 60 Hz range on the generator's gauge. I stopped and started it several times with the same results. ... Or maybe it's a dreaded intermittent problem.

Ref Post 60:

The plot thickens. I went out and started it again. Frequency went right to 60 and remained. Voltage went over 300 on the gauge. As I walked down to the garage to get the Fluke, I heard the tone of the motor change a couple of times like it slightly loaded, and then went back to normal. Nothing is hooked up to this generator, by the way. When I made it back, I had no frequency or voltage. The convenience outlet read 0.43v.

It sure seems like it's pointing to an intermittent problem with the VR seemingly working properly at times. I had a similar problem with voltage intermittently shooting high until it consistently shot high and stayed there. Turned out to be a broken winding lead coming out of Transformer T1 if I'm recalling correctly (or maybe it was T2?). It was the one that is mounted inside the control panel box at the top left side back area. The small transformer winding wire (that attaches to the screw terminal that has a wiring harness ring terminal attached) apparently was making intermittent contact until it finally opened up enough to fail consistently causing high voltage of something like 175 VAC. It was a lacquered wire that comes out from beneath the kraft paper protecting the windings on that transformer and soldered to back of flat screw terminal on that transformer. From looking at the schematic T1 & T2 transformer do provide input voltages (reference voltage?) to the VR. If the isolation dampeners on your control panel box are going bad (visible shake movement) it can result in a LOT of vibration that can take its toll on any small wires like those used in transformer windings leads within that cabinet. So I would go over and inspect every wire on those transformers as well as others inside the control panel.

 

[Guyfang]

I would check the wires and T1 and T2 because its cheap. But I might be sending a PM to someone about a new VR also.

 

[Guyfang]

The K3 has two terminals, A1 and A2. They are for the starter Sol.

the other two wires are X1 and X2. Those two wires are to close the K3. One of the wires goes through a TB, and ends up at S1.

The two wires with yellow terminals, were A1 and A2. They definitely had something to do with start problems. I want to look at the schematics in the morning. It's 01:30 here.

Had this been X1 and X2, I would have said, yeah, this might have an impact on the excitation, because of TB4-10. If the wires didn't make good contact, or were off of the terminal and touching ground, yeah.

 

[juddspaintballs]

Thanks, guys. I've placed an order for a new AC VR. I also placed an order for a NOS stator so I can fix my DC charging system. I'll let you know if the VR fixes things when it comes in. In the mean time, I'll check the T1 and T2 wires just to be sure.

 

[Triple Jim]

The regulator will be on the way to you tomorrow morning. I had to build one for you, but I got it together and tested last night, and the conformal coating is drying now.

 

[juddspaintballs]

Excellent! I wasn't expecting you to be done with it so soon.

 

[juddspaintballs]

Thank you to Triple Jim for shipping the regulator very quickly. I received it today and installed it.

No luck. I'm not upset I bought a VR from him at all. It was in the future plans anyways. If I remove terminal 17 on this VR as well, voltage goes above 300 on the gauge. If I install terminal 17, I get no voltage (0.4x volts AC). Crap.


I'm all ears. I don't even know where to go from here other than throw money at a linear reactor and hope for the best.

 

[Ray70]

As an option I have a couple parts machines ( MEP-002A's) I just bought, if you want, I can help with a linear reactor, CVT1 or even an AC reconnect box, if you want to either swap it out and test or buy and replace anything.
I'm open to letting you borrow parts to test with ( just pay for shipping ) , then if you find the problem and want to keep anything I'll sell you whatever you need.

 

[juddspaintballs]

Thank you for the offer, Ray. I did order a linear reactor today. If that doesn't work, I'll take you up on it.

 

[jamawieb]

Thank you to Triple Jim for shipping the regulator very quickly. I received it today and installed it.

No luck. I'm not upset I bought a VR from him at all. It was in the future plans anyways. If I remove terminal 17 on this VR as well, voltage goes above 300 on the gauge. If I install terminal 17, I get no voltage (0.4x volts AC). Crap.


I'm all ears. I don't even know where to go from here other than throw money at a linear reactor and hope for the best.

Did T1 and T2 test good?

 

[juddspaintballs]

I didn't see a procedure for testing them. I did a visual inspection of both and I couldn't find any disconnected little red wires in the transformers from the backs of the screw terminals.

 

[Guyfang]

This was in the -12 TM.

(14) Transformer (T1) (see figure 4-33). Tag and

disconnect five leads to transformer T1. Using an ohmmeter
check primary winding by measuring resistance
from terminal H1 to H2. Resistance should be 18.6
ohms ± 1.86 ohms. Check secondary winding by measuring
resistance from terminal X1 to X3. Resistance should
be 1.6 ohms ± .16 ohms. If either of the windings do not
show the proper resistance. replace transformer.


(15) Transformer (T2) (see figure 4-33). Tag and
disconnect four leads to transformer T2. Check primary
winding by measuring resistance from terminal H1 to H2.
Resistance should be 155 ohms ± 15.5 ohms. Check secondary
winding by measuring resistance from terminal Xl
to X2. Resistance should be 18.8 ohms ± 1.88 ohms. If
either of the windings do not show the proper resistance,
replace transformer.

 

[Guyfang]

As an option I have a couple parts machines ( MEP-002A's) I just bought, if you want, I can help with a linear reactor, CVT1 or even an AC reconnect box, if you want to either swap it out and test or buy and replace anything.
I'm open to letting you borrow parts to test with ( just pay for shipping ) , then if you find the problem and want to keep anything I'll sell you whatever you need.

This is a good idea!

Keep in mind, that the 002A and 003A output boxes are NOT the same. There are some differences. 98% of the components ARE the same. Also the CT's are wound different. By that I mean the output wires are supposed to go through the CT's For the 003A, a different amount of times then the 002A. Please look, and count. I dont remember the numbers, and I have to leave soon for a few hours.

Also the adjustment of R2 in the output box would need to be re done. I am fairly sure, the 002A box will KINDA work, in the 003A. BUT, the CB1 in the 002A box will kick off at 5KW, so if its used in the 003A, you need to keep that in mind.

 

[juddspaintballs]

I'll try to get to testing the transformers on Thursday when I get home. Are the T1 and T2 transformers the same between MEP-002a's and MEP-003a's in case I need to take Ray70 up on his offer?

 

[jamawieb]

I'll try to get to testing the transformers on Thursday when I get home. Are the T1 and T2 transformers the same between MEP-002a's and MEP-003a's in case I need to take Ray70 up on his offer?

Yes

 

[Chainbreaker]

...Are the T1 and T2 transformers the same between MEP-002a's and MEP-003a's in case I need to take Ray70 up on his offer?

Yes, they are the same and are available new and used. T1 is a 5 lead and T2 is the 4 lead one. PN's are in the -24P TM.

 

[Triple Jim]

My money is on a bad CVT1. Without going back to read all the posts in this thread, did you measure all the windings in it and compare to the values in the TM?

 

[Ray70]

I thought CVT1 as well, but he tested it and said it checked out OK, unless it has an intermittent problem? Guyfang is correct in that the windings through the CT assy. will be 3 wraps Vs 4 wraps, but testing with one from a 002A as-is will still work testing purposes.