2X MEP-802A Dead on Arrival... won't crank... Crank Relays Dead

[heavyzee]

The one i was working on, now runs, and runs STRONG! Had to play replace a few connectors on the fuel pump, and fixed the relay.

Now i am getting a short circuit/ overload light (depending on how the MEP feels) - i assuming its the far left relay in the electronics - i will dissassemble it today.

Not getting any power to the output lugs, but am getting power in(120v) to the GFCI (i think this is busted, as it wont reset - any fix ideas here?)

Still waiting on a new crank relay for the other machine, and need to build or find some sort of load tester

 

[Guyfang]

The one i was working on, now runs, and runs STRONG! Had to play replace a few connectors on the fuel pump, and fixed the relay.

Now i am getting a short circuit/ overload light (depending on how the MEP feels) - i assuming its the far left relay in the electronics - i will dissassemble it today.

With the load turn on? Or no load.

Here is a good trick. Turn off the lights, or do this when it's dark. Start up the set, with the control panel open. Watch for a spark. Lots of times, it's the wires on the Burden resistors are mounted on a plate. It's all the way to the left, bottom of the control panel

Not getting any power to the output lugs, but am getting power in(120v) to the GFCI (i think this is busted, as it wont reset - any fix ideas here?)

Did you press the reset button? Not the button on the panel. Open the control panel door, and find the reset button on the side of the CB3. If you have no output on the lugs, and you have pushed the S5 up, then your K1 is not energizing. Look at the TM for the test procedure. Remember me saying they get water in them?

Still waiting on a new crank relay for the other machine, and need to build or find some sort of load tester

a

 

[heavyzee]

No load, nada, nothing.

I have tried the inside reset button CB3, not sure if faulty or what, doesnt seem to have a grab when reset or anything

a

 

[Bmxenbrett]

Check it with your volt meter.

 

[Guyfang]

Start the set. Follow the wires from CB3 back to the terminal board in the control panel. Measure at those two terminals for 120 volts. If you have 120 volts, and have reset the CB3 and still have no voltage at the 120 volt outlet, the the GFI is bad.

 

[heavyzee]

CB3 is bad for sure. we have 120v at the terminals. replacement on the way

On to the next big hurdle... The Short Circuit Overload Relay was full of water... pulled it apart, and whoosh agua...
NSN # 5945-01-366-2726 Part# 19230

ebay has two... unknown working order... blah...

 

[m32825]

I used to buy '80s arcade games and get them working again (Tempest, Stargate, Robotron). Some of the boards, especially for Williams games, could be swapped out of a common chassis to change the game. By the time I got them, these boards had been tossed on a shelf in a warehouse for a decade or so. They were covered with all kinds of dust and grime. Standard recovery procedure was to blow off the easy stuff then go after it with a garden hose and tooth brush. Afterwards, blow it off and let it dry thoroughly in the sun before plugging it in. I mention this because the level of electronics in the design seems similar, it may be fine if you clean it up and dry it out.

-- Carl

 

[Guyfang]

Please keep in mind, this part fits in the entire TQG family, 5KW to 60 KW. So when you search, don't just search under 802 or 803A.

 

[heavyzee]

ok, stole the short circuit relay from generator set 2 - looked better inside (though still full of water)

Also installed a new GFCI that came in...

V5 Veristor is broken, so need to order a few of them, figure ill get some other needed parts with the order from Mouser for the V68MA3B Veristors

For other gen set i am going to need a diode for the start switch, i couldn't find the PN for that one in the TM MEP-802A-TM9-6115-641-24P

anyone have the part number for diode CR4 on the schematic?

 

[Daybreak]

Howdy,
Start switch diode assembly 88-22418-1
View attachment 75902LV_REVD.pdf

 

[kloppk]

...

Anyone have the part number for diode cr4 on the schematic?

1n5406

It's item # 21 in the Control Panel and Box Assembly figure in the -24P TM

 

[heavyzee]

1n5406

It's item # 21 in the Control Panel and Box Assembly figure in the -24P TM

yes it is... i misread the diagram, and was looking at #33 as the start switch... DOH!

 

[Guyfang]

A fella could spend his whole life improving these books.

 

[heavyzee]

took delivery of varistors, diodes, and a few new capacitors im going to use to try and fix one of the short circuit relays with.

I have consolidated the "good"(dried and cleaned) short circuit relay to the known runner, and am planning on installing the replacement varistor tonight.... hopefully this gives me 1 running power producing gen set....

 

[Guyfang]

It also gives you a way to system check components. VERY handy.

 

[Bmxenbrett]

I had a bad diode on a set a while back. No power to start switch. Read the numbers on the diode and orderd it online. I had to buy 10 so if you need one pay shipping and $1 il send you one.

 

[heavyzee]

Replaced - V5 - Have continuity across it (testing wires)
Replaced CB3 - continuity through
Swapped over unknown Short circuit relay from other non-working gen set

Will not turn over now
Shows low fuel fault - reset it over and over
No more short circuit or overload fault (yay?)
Fuel pumps run
tried battle switch no bueno (check continuity across switch, and working properly)
Heater relay works (clicks)
Can close power interrupter relay (clicks)
power at S1, and power leaving S1 through 7 when turned to start. power not reaching crank relay to initiate starter....


dead crank switch does turn engine over, as does jumping the crank relay, and jumping power to the relay to actuate it

im going to try and read the schematic again tomorrow... too tired to look at that anymore...

question, on the relays K15 for example.... when A and B are energized, 1+7, 2+8, and 3 +9 are in contact, when a and b are non energized 1+4, 2+5, and 3+6 are in contact?

 

[Guyfang]

Open up the front panel, see if fuel level switch is working properly. Take it out, and test FL1 and FL2. That's were the signal comes from to trigger the low fuel relay. When it shuts down for low fuel, It will not allow you to start the engine,BUT will allow you to use S10. If the FL is good, the swap out your relay, with another.

 

[heavyzee]

This is on hold till i get my forklift picked up tomorrow. 2 gen sets are front to front, with little to no access to front panel...

 

[heavyzee]

forklift in, gen sets removed from trailer. Pretty sure the issue with the low fuel is someone had cut the connectors off and now the 4 wires between the Fuel Pump Float Switch and the fuel float module are crimped togethor. unfortuntally i dont know which wires are which coming off the float switch, just 2 red and 2 black, and they are hooked to red-1 red-2 black-3 black-4... seems wrong, but havent messed with it tooo much.

If i disconnect the fuel float module, the gen set runs great. After replacing the GFCI, i now have power at the convenience recpticle. I hooked up a 220v range to the set, with no power being generated through the lugs.

After switching the AC circuit interruptor closed, i see the rnage gets power when i hold the switch in the closed position, but will not stay on??