Community Forums

toolster · 07-23-2015, 04:24 PM

With shore power connected I have power to most outlets, fridge and partially the microwave. No a/c water heater or microwave heating. The
power display shows 50amp and will not change and does not show the amps being used.(I have only 20amp shore power connected). If I start the genny everything becomes normal, everything works and the power display changes to 'gen' and shows the amps being used. Anybody have any ideas ?

ImagineIF · 07-23-2015, 04:53 PM

Based on your brief description you probably have a bad 15/20A 120V to 50A 240 adapter. My guess is the 20A feed is only getting to one of the two power wires in the 50A plug.

toolster · 07-23-2015, 05:52 PM

That sounds reasonable as its the heavy use items that are not working. it would also explain why the genny would still power everything as that produces 50 amp. Any idea where this adapter may be located ?

ImagineIF · 07-23-2015, 06:45 PM

I am assuming your RV has a 50A 240 V shore power plug. The only way to plug it into a 20A circuit is with s short adapter cable. That adapter cable would be the problem.

You also say your power display shows 50A. What is this display? The EMS systems I'm aware of turn off some breakers when you have less than 50A. These determine 50A by measuring voltage between the 2 hot leads in the 240V input power. It,'s impossible to read 240V from a 20A 120V outlet.

toolster · 07-23-2015, 07:05 PM

Just switched the adapter to a new one and didn't make a difference so its not that. The EMS normally shows 30amp when I'm plugged in in my barn, and 5-6 amp draw, now it shows nothing being used although the fridge is on and the battery float charger is working.

toolster · 07-23-2015, 07:31 PM

Somebody suggested the my transfer switch is stuck in the generator position, is this possible and still allow some power to come in to power the fridge and wall outlets. If so how do I unstick it ?

jacwjames · 07-23-2015, 08:22 PM

If you are getting shore power using a 20 amp plug and then when you start the generator everything works tells me your transfer switch is working. When the generator is running it sends a signal to the EMS system and it takes priority and everything will run.

If you are not seeing any amps on the display the EMS thinks it is plugged into a 50 amp circuit, it does not show amps when plugged into 50 amps.

It sounds like your EMS system isn't working right. The first thing to do is try to reset it. I do not know how yours is wired or configured but mine is near the main 120 volt panel in a brown enclosure. Unplug the shore power and do not run generator. Take off the cover plate, there should be a circuit board located near the breakers that wires run to, this is the EMS circuit board. On the back side should be able to see a ~5 amp automotive type fuse, take it out for ~10 minutes. This is suppose to reset the EMS.

If that doesn't work then you have bigger problems.

My EMS system completely stopped working last December and I had to replace the board and upgrade to a newer version. I contacted M&M Electronics, they can help you trouble shoot the system if it is Intellitec.

Call
419-965-2662.

ImagineIF · 07-23-2015, 08:27 PM

If the transfer switch was stuck you'd have nothing. It is possible the transfer switch has on set of contactor's that aren't making a good connection.

If you have a multimeter check the power. Check it at the entrance breaker or transfer switch or power panel breaker, which ever is easiest. The voltage flow is in the order I listed. Both power feeds should measure 120V to ground or neutral.

falconman · 07-23-2015, 09:50 PM

I would check for power on both legs of the shore power at the ATS. Maybe the SP cord or plug itself is defective.

toolster · 07-24-2015, 02:18 PM

Thanks everybody, I followed your suggestions and found the problem, the 50amp plug had been replaced by the previous owner and the wire not secured in the plug resulting in them coming loose. Rewired the plug correctly and all is now working fine.

ShapeShifter · 07-24-2015, 02:33 PM

EDIT: sorry, I didn't see the "it's fixed" post until after making the post below. I guess it's moot now.

I'm with jacwjames on this one. From the OP's description, it sounds like he has an Intellitec EMS.

toolster: If it says Intellitec under the Amps display, do the reset jacwjames mentions. Rather than open up the cover to the EMS, which is also the cover of the breaker panel, you should be able to find the fuse that powers the EMS and pull that - it might be a bit easier. On my coach, it's in the closet, near the breaker panel, labeled F18 EMS (OPT)

I've had mine "get lost" in the past, and the classic symptom is that it is stuck on one particular shore power type, and if any load shed LEDs to the right of the Amps display are off, nothing will bring them on. This sounds like what you're reporting, except that turning on the generator apparently overrides the display, I didn't try that when mine was stuck.

As was mentioned, it looks for there to be 240 volts across the two hot leads, and if it's there, it says it's 50A. Since you are using a 20 amp source, which is strictly 120 volts, there is no way it's seeing 240 volts, so the power management logic must be confused. Perhaps it's just the voltage sensing that's stuck, because the generator mode is triggered by the 12 volt run signal from the generator (the same signal that lights up the generator "running" indicator.

Since it's obviously confused, it's definitely worth a reset: disconnect all AC and 12 volt DC power for several minutes. It's not guaranteed that will fix it, but well worth a try.