802a help

[jjb2001]

I just bought one of these to power two ice eaters for waterfowl hunting. Everything worked fine for awhile and now it started throwing an over load fault while running 3 motors So I unplugged one motor and now it throws a short circuit fault after about an hr of run time.
Here is how it’s wired. And after reading about grounding the genset I have the ground rods and wire to do that. It is currently not grounded. I will rectify that when I get to the genset. Im away at work for the next couple days so I’m not at the genset til then.
R/

 

[Ray70]

Are they 120V single phase motors? How do you have the generator AC select switch set? are you in 120 / 240V mode, switch behind the control panel in the right hand position?
And are you hooked up to L1 L3 and L0?
Or are you running in 120V only mode with wires on L3 L0 and ground with the AC select switch straight up?
And... do you have the ground bonding bar in the lower right corner of the terminal board attached or removed?
This info will start leading us in the right direction.

 

[jjb2001]

Single phase 120 motors. L1 and l3 are hot and lo is neutral I bieleve. I’d have to check on the grounding bar. I’m running it as i bought it. It worked flawlessly until I hooked 4 1hp motors to it. I started them individually and waited for them to ramp up before starting the next one. When the last one was started the generator load was at 120% then calmed down to 90%. Ran for about ten min and the overload tripped. So I backed off to two motors and it ran a week straight with no issues. Then it started the short circuit fault.

 

[kloppk]

Get the set properly grounded first as Ray indicated.

An overload occurs when the set "thinks" it sees a load of 425% on any output leg.

Poor contact inside the AM/VM switch and the Voltage/Phase reconnection switch can cause false Overload and Short Circuit faults.
With the set OFF I'd suggest...
Exercise the AM/VM switch thru it's settings a number of times and then return it to the original position.
It's recommended you spray some Deoxit contact cleaner into the switch before exercising it.
Do the same for the Voltage/Phase reconnection switch. You'll need to remove the top cover to get to the switch to spray Deoxit in it.
Exercise the Voltage/Phase reconnection switch thru it's positions a few times and return it to the original position.

Then start the set and see if you get any Overload or Short Circuit faults or if the problem has cleared.

If you still get Overload or Short Circuit faults then you'll need to take some AC voltage readings across 3 resistors to narrow down where the problem is.
With the gauge panel open you'll see a board on the far left on the back wall.
Picture of the board with the resistors on it below.
You'll need to set your hand held meter to AC volts and connect it across the the two terminals on R10.
Start the generator and put a load on both the L1 & L3 output legs.
The AC voltage should be less than 5.6 volts AC.
Repeat this for R11 & R12. All readings should be less than 5.6 volts AC.
5.6 volts AC corresponds to a load of 100%.
0 volts AC corresponds to a load of 0%
7.5 volts AC corresponds to a load of 133%

 

[Ray70]

So, just like Kurt explained, the first thing I would do is exercise and clean both of the switches ( well... second thing after getting the set grounded properly )
Also, are you sure your motor loads are fairly balanced between L1 and L3?

Another thing I would try is setting the machine to the 120V setting and putting all your hots on L3.
Part of the problem might be a grossly unbalanced load, so if you are running in 240V mode and all your load is on one hot leg, you will only get 1/2 your rated output before it trips off.

 

[jjb2001]

I’m not sure that all my loads are on the same leg. As I’m using an outlet to power the motors. I have two outlets. And last time they were plugged in was by my nephew. If I’m pulling all of the same leg I’ll change it to pull off both. I think I might try running on 110v and not splitting 240 in the breaker box. Just run both leads to l3 to put power to both sides of the breaker box. I get home tonight and will start digging into this. Thanks for the help.

 

[Ray70]

Guess it all depends how your outlets are wired, but most likely each outlet is powered off a different leg. If you have 1 motor on each outlet you are probably good, but 2 motors on the same outlet means you are loading only 1 leg.
Either way the 120V powering L3 only is a better choice for what you are doing, but exercising the switches and verifying voltage across your burden resistors is still just as important.

 

[jjb2001]

So I have 2.36 volts across R10 r11 r12. With about 30% load on the load gauge. And 0 volts across all three with no load.

I switched the generator over to 120 single phase grounded the generator. The generator and everything worked fine for about 30 min then the short circuit light came on. I reset everything and as soon as I applied a load it short circuit faults. With the ac switch closed everything is fine and the short circuit light won’t come on as soon as I flip a breaker in the breaker box to turn on a motor it fails.

 

[jjb2001]

I thought maybe my 5 conductor 6 awg cable I ran maybe got nicked but that wouldn’t explain why it worked for 30 min then shut off. It’s almost like it works when cold then as it warms up it’s starts failing.

 

[uniquify]

How long is your power cable?

 

[jjb2001]

500 ft. I have 2 hot conductors 2 neutral and one ground.

 

[uniquify]

Does the power cord get warm during use?

 

[jjb2001]

No

 

[kloppk]

The voltages at the burden resistors look good.
The K8 Overload / Short Circuit module monitors these 3 voltages to determine if there is either an overload or short circuit condition.
Overload starts to occur if any one of the 3 voltages is 7.5 volts AC or higher (133% rated load).
Short Circuit occurs when the AC voltage is any of the 3 voltages are 23.9 volts AC or higher.

Since you describe it happening when the set gets warm ~30 minutes with load applied it may be K8 module may be faulty.
Also if one of the burden resistors R10, R11 or R12 is going bad and "opens up" after it warms up would trip an short circuit fault.
Other things I can think of is if some connection is loose in the current transformer, S6, S8 R10, R11, R12, K8 wiring is loose and is opening up causing the fault.

 

[Light in the Dark]

If you need a new K8 I have a couple listed in the classifieds here: https://www.steelsoldiers.com/threa...elay-88-21141-5945-01-366-2726-120-ea.197053/

 

[jjb2001]

The voltages at the burden resistors look good.
The K8 Overload / Short Circuit module monitors these 3 voltages to determine if there is either an overload or short circuit condition.
Overload starts to occur if any one of the 3 voltages is 7.5 volts AC or higher (133% rated load).
Short Circuit occurs when the AC voltage is any of the 3 voltages are 23.9 volts AC or higher.

Since you describe it happening when the set gets warm ~30 minutes with load applied it may be K8 module may be faulty.
Also if one of the burden resistors R10, R11 or R12 is going bad and "opens up" after it warms up would trip an short circuit fault.
Other things I can think of is if some connection is loose in the current transformer, S6, S8 R10, R11, R12, K8 wiring is loose and is opening up causing the fault.

It reminds me of a coil for a spark plug. Works fine cold but warms up and fails. I’m headed back to the set this morning with daylight this time and try to investigate further. I’ll take pics this time.

 

[jjb2001]

I just went and started it. As soon as you apply a load it short circuit faults now.

 

[kloppk]

Does the engine bog down indicating a heavy load before it throws the fault?

With the set OFF you could try measuring the resistance of the 3 resistors. They should be 7.5 ohms.

 

[jjb2001]

If you need a new K8 I have a couple listed in the classifieds here: https://www.steelsoldiers.com/threa...elay-88-21141-5945-01-366-2726-120-ea.197053/

I would take one. How do I pay for it?

 

[jjb2001]

Does the engine bog down indicating a heavy load before it throws the fault?

With the set OFF you could try measuring the resistance of the 3 resistors. They should be 7.5 ohms.

No it does not big down. It was 12 degrees this morning and the genset fired right up. I waited ten min and hit the ac close circuit. As soon as I hit the toggle switch it went into short circuit fault. I have a gas 5000w generator running the motors now and it is doing fine. So Im pretty sure the problem is with the generator not the electric motors.