MEP-803a overload circuit

[TNriverjet]

I will to unhook everything and take a look at connections on the K8. I did have a mouse nest under the transformer (since cleaned out), so I will check out the K8 to be sure there is no corrosion. I will also count wraps of wire. The -24 TM states 4 wraps. Mine appeared to have more wraps that that. Are the doubled and the count needs to be divided by 2?

 

[Haoleb]

It looks like the CT is wound properly. Two wires going through each CT 4 times, looks like about 8 loops of wire on there.

 

[jamawieb]

There is a connection board located under the old rat nest, make sure all those connections are tight and not corroded. Rat urine will cause serious corrosion. I had an 802a that had 1 loose connection on that board, that caused a O/L and almost melted the connector. Also spray the AM/VM switch on the front panel while turning it and make sure all those connections are tight. On the reconnection switch, make sure you are spraying from the bottom, sides and not just from the top.

 

[Guyfang]

Take the time to unscrew the CT, and check that Mr. and Mrs. mouse did not remove some of the wire insulation from your load wires, or the TB below, to renovate their condo. It's a PITA, but there could be your problem.

Do not, unless you really have to, remove the 6 wires attached to the front of the CT. The studs can and will break off, sometime very easy.

I would say that the load wires look about right, but if you can check the wire numbers against the wire diagram, it will not be a bad thing. In fact, you have no idea what happened to this machine before you got it. That's why, if I disconnect ANY wires from ANY component, I would NOT mark the wires, or components. I WOULD get the wire diagrams out, and replace the wiring IAW the wire diagram. In theorie, your problem could be something miswired. If you reattach wires in the same order that you took them off, and don't check the wire diagram, you simply compound the problem. For me, everything in the gen set is suspect, until I che checked it out, or have seen the set work right.

When you rotate the S8, (and for that matter, S6), how does the switch feel? Smooth? Or hard, gritty? The S8 and S6 are of a switch type that allow dust and dirt to enter the switches, over long time periods.

I cant tell from the picture, but does your set have the quad circuit fuse, mounted next to the A1, AC volt regulator?

Oh, please take the time to remove the negative battery terminal before unhooking stuff, working with metal tools or hunting for Easter eggs. To the right of S6 for instance is MT4, (ammeter shunt) if you drop a wrench on it, you will be seeing spots before your eyes for a while. Safety First.

 

[Dwnorton1]

For me, everything in the gen set is suspect, until I che checked it out, or have seen the set work right.

Fully concur.

 

[TNriverjet]

When you rotate the S8, (and for that matter, S6), how does the switch feel? Smooth? Or hard, gritty? The S8 and S6 are of a switch type that allow dust and dirt to enter the switches, over long time periods.
I cant tell from the picture, but does your set have the quad circuit fuse, mounted next to the A1, AC volt regulator?
Oh, please take the time to remove the negative battery terminal before unhooking stuff, working with metal tools or hunting for Easter eggs. To the right of S6 for instance is MT4, (ammeter shunt) if you drop a wrench on it, you will be seeing spots before your eyes for a while. Safety First.

The switches feel smooth with positive engagement. I've sprayed them both with electrical contact cleaner. This flashes off pretty quickly and dries things out. I plan to pick up some "Deoxit" today which also has some some lubricating qualities.

I do have the quad circuit fuse added. See photos below. I should add this is a low hour (8 hrs, now has 15hrs) unit refurbished by Oregon RSMS in 2010. I do however agree that it still could be wired incorrectly.



Here re are a few more pics of connections, etc



Some of the stuff behind the front panel looks new. Thanks on the battery disconnect suggestion. I was under the impression shutting off the dead crank switch disconnected power. Yes, I know what "a&&"uming will get me...

 

[jamawieb]

I still think you have a dirty connection causing the problem but you can also de-solder the burden resistors and check them with and ohm meter. They are part of the control circuitry but I've never had any go bad to show O/L. I've had a couple go bad that would set off the short circuit malfunction but not the overload.

 

[TNriverjet]

I still think you have a dirty connection causing the problem but you can also de-solder the burden resistors and check them with and ohm meter. They are part of the control circuitry but I've never had any go bad to show O/L. I've had a couple go bad that would set off the short circuit malfunction but not the overload.

I did a bunch of disconnect/clean/reconnect on the K1 and TB3 yesterday. I also used a can of Deoxit D5 on both rotating switches while working them back and forth. Deoxit doesn't flash off as quickly as E/C cleaner, so I've let it sit overnight to "dry out" a bit. I plan to hook up a load and test later today. The connections on TB3 were a bit dirty, but tight and everything basically wiped off. I still used some emery cloth lightly on the base and connectors to make sure.

 

[TNriverjet]

I ran a load test again Wed. It tripped the overload on anything over 50% (took 10-15 min), so something has improved. I was able to run 50% or less for over an hour before I had to shut down. I plan to dig deeper on cleaning and tightening connections. The load board is my next target. The lugs look brand new, so I'm wondering if all connections behind are good.

 

[Guyfang]

Can you get a clamp on Amp meter? One that holds the highest reading? Then load it up, and measure each leg. See just what Amperage you are, drawing.

Is any carbon comming out of the exhaust? Does the exhaust smell funny. A bit oily, or like diesel? If so, load it to 30-40% and let it run 1-2 hours.

 

[TNriverjet]

I had some time last weekend to tighten load lug connections on rear of the load center. I was finally able to run it tonight for 1.5 hours at just under 50% load. Some may enjoy a short video.

https://www.youtube.com/watch?v=9XtO4TD2i10

 

[Guyfang]

Now, can you step it up just a little bit? See if it will work.

 

[Dwnorton1]

Sounds nice. We can start the baking cookies while load testing 803 club. I was doing night OPS in my pic. 42FLA with all burners on 34amps during cycles on burners.

 

[Guyfang]

Looks like a bunch of UFO's

 

[Dwnorton1]

Looks like a bunch of UFO's

More Okla UFO's

 

[CT-Mike]

Do you have a ground rod driven and connected when you are testing this using the stove? If not, I would highly recommend doing so to prevent possible serious injury or death. Just my $0.03 (adjusted for inflation).

 

[CT-Mike]

Also remember as mentioned above the the heater elements in the stove are purely resistive, ie: pF = 1.0. These gensets are rated for a pF of 0.8, so you need to divide your indicated load by 0.8 to get true load.

 

[Dwnorton1]

Mike thanks for looking out for us. I would not consider running a load test without having unit and distribution grounded. That is very good advise. Ground fault with no path could result in very bad day. Also had neutral bonded to ground at gen. By my calcs the 42fla at 1PF is pretty close to max capacity of an 803. Might be able to squeeze 7 more amps inductive before approaching 125%. Didn't try it, but could probably get by with it. Would not believe the carbon sparkles that came out exhaust.

http://www.youtube.com/watch?v=q5b4vMBjjxQ

 

[TNriverjet]

Do you have a ground rod driven and connected when you are testing this using the stove? If not, I would highly recommend doing so to prevent possible serious injury or death. Just my $0.03 (adjusted for inflation).

I do have an 8' ground rod near my load test area. I also have the neutral and ground bonded at the genset as is required for a stand alone system.

 

[Guyfang]

Mike thanks for looking out for us. I would not consider running a load test without having unit and distribution grounded. That is very good advise. Ground fault with no path could result in very bad day. Also had neutral bonded to ground at gen. By my calcs the 42fla at 1PF is pretty close to max capacity of an 803. Might be able to squeeze 7 more amps inductive before approaching 125%. Didn't try it, but could probably get by with it. Would not believe the carbon sparkles that came out exhaust.

http://www.youtube.com/watch?v=q5b4vMBjjxQ

Oh yes I would believe the carbon sparks! We set the woods on fire behind my shop in Kaiserslautern!!