Is My Automatic Transfer Switch gone?

[Mike and Pat]

Usually I turn off all high draw items and start the Generator before I leave a campsite and the go out and unplug the electrical cord and do the reverse when I get to a new camp site (turn off al high draw items and the plug in the electrical before turning off the generator) In the past there was no problem. The Power Management System would show generator power only until I shut the generator off and then would show 50amp if that is what I was plugged into. And iff I were to start the generator before I unplugged the electrical cord it would show 50amp until the generator came on line and then switch and only show the generator. Lately it has been showing both sources at the same time. I have quickly removed one of the power sources as soon as I saw this. So is my Automatic Transfer Switch gone?

[Sammie]

Sounds like your Intellitech Power Management circuit board may be on the fritz. Call them and Im sure they will help you. 1 800 251 2408.

Sammie.

[wa8yxm]

I too think it is the board, not the transfer switch... The reason is the EMS has to be able to sense the difference between shore and generator power. (I do know how it does this) and between 30 and 50 amps (likewise) and about the only place that it has the sensors is on the board.

[John Hilley]

I don't understand why you keep a continuous source of power. Do you keep the generator running continuously while traveling?

If you don't need continuous power, you are needlessly exercising the transfer switch and generator. I would disconnect the battery and see if that resets the Intellitec.

[Mike and Pat]

Thanks all for your replies. John, Usually don't but in some cases I run the generator while traveling to use the A/C. And that is when I noticed it first. I didn't think much of it until we lost power a few weeks back and of course I started the generator and in the past I would never know if I had shorepower back unless I looked out the window and saw that the surgeguard lights were on. This time I walked past the EMS and saw lights on for both Generator and 50amp. I quickly killed the generator. I use a auto generator start but now am afraid to use it if the transfer switch is letting both power sources through.

[garykk]

Originally Posted by John Hilley

I don't understand why you keep a continuous source of power. Do you keep the generator running continuously while traveling?

If you don't need continuous power, you are needlessly exercising the transfer switch and generator. I would disconnect the battery and see if that resets the Intellitec.

My thoughts too.....sounds like the gentset is running steady while on the road??

[Wizard]

I do things a little different, I always remove one power source before energizing the other. If you ever had a short around the transfer switch there would be the possibility of a very big explosion and fire. Not worth taking the risk to me.

[Jbmsr]

The transfer switch can only accept one source of power at a time. I would call the manufacture and speak with a tech. They most likely will have the answers for you. They might be able to walk you through with a fix.
Jesse

[Mike and Pat]

I will give them a call and see where we go from there. That is why I have been a member of this forum for so long. I always get great answers and guidance and am never left wanting. You guys are the best.

[John Hilley]

Originally Posted by Mike and Pat

Thanks all for your replies. John, Usually don't but in some cases I run the generator while traveling to use the A/C. And that is when I noticed it first. I didn't think much of it until we lost power a few weeks back and of course I started the generator and in the past I would never know if I had shorepower back unless I looked out the window and saw that the surgeguard lights were on. This time I walked past the EMS and saw lights on for both Generator and 50amp. I quickly killed the generator. I use a auto generator start but now am afraid to use it if the transfer switch is letting both power sources through.

Contrary to what jbmsr said, the transfer switch can accept both power sources simultaneously. If the generator is on, it will activate the contactor and the power into the coach will be coming from the generator. The shore power will be terminated at the switch and cause no problems. The EMS is past the transfer switch and isn't affected by the transfer switch.

[Dave78Chief]

The Powerline EMS operates independently of the ATS switch.
1. When the EMS system detects 240VAC a the L1/L2 leads it lights the 50 AMP service light
2. When it senses 120VAC at L1/L2 and the 12VDC Generator power on signal it lights the GEN light. (Assumes 30 amp service)
3. When it senses 120VAC at L1/L2 and no 12VDC Generator power on signal it assumes 30 amp shore power service. You have to manually select 20 amp service if that is the actual source.
4. The manual (http://janeandjohn.org/docs/EMSmanual.pdf) does not indicate what would happen if you had 240VAC at L1/L2 and the 12VDC Generator power on signal is present. I suppose it is possible the GEN light is controlled by the 12VDC signal from the generator.
5. Only way the 50 amp source should light is if 240VAC is available. If the ATS did not auto switch gen as supply when gen is ON (normal operation for the ATS switch), then 240VAC from shore power would be present at the EMS.
If you do not understand all this then get someone who does in order to determine what the actual situation is.

Dave

[Pusherman]

First off, the generator always has priority over shore power from the transfer switch. IF both are powered at the same time, the generator will supply the power.

Secondly, even though it's technically OK to power both sources at the same time, and is not a safety concern, it does put additional wear on the transfer switch contacts when both sources are powered, which may cause premature failure of the transfer switch.

Best practice is to disconnect shore power and then fire up the generator. Saves the transfer switch contacts.

You may either have a transfer switch issue, but most likely, I agree with the above posts, which suggest it is the EMS control board which may be faulty.

[jerichorick]

Just a thought about all of this from my power days. If you try to mate two separate a out of phase sources together you will get a catastrophic failure. This has been mentioned above.

I wonder if your switch has some sort of sense wire that I am not familiar with.

As I understand it, and this may already be stated, if L1 and L2 are in sync the EMS sees it as generator. If L1 and L2 are 180* out of phase the EMS sees 50A service. If only one leg has power it see 30A service.

Just for a good troubleshooting exercise consider doing the following: Disconnect the shore power and shut the generator down. Remove the cover from the transfer switch and check the tightness of all the terminal screws. Next, power down the inverter and open up the breaker panel. Do the same there. Put the covers back in place and test.

Transfer switches defer to the generator. The power from it energizes the relay coils. Your EMS must be different than mine. I get a word readout that tells me the power source and line condition.

Your practice of shutting down loads before connect or disconnect is a very good one. I don't know if I agree with running the generator though. The inverter, if on, will activate and provide essential power as long as the house batteries are working. Once you start you engine the alternator should provide enough amperage to keep things fed by the inverter working.

It is common to run the generator for A/C utilization on hot days when the dash air just won't cut it. But that is the only time I will use it when driving.

I look forward to seeing what fixes your unique problem.

Best wishes and a speedy fix,
Rick

[dengraham]

What Pusherman said is correct. If you turn OFF all the power the transfer switch will pull relay to the default Generator position. If you have power from both the shore power AND the generator; the transfer switch will also default to the Generator position. So, as stated if they are both powered (i.e., live) you are causing small "sparks" at the contacts are disconnected and connected from shore power to generator.
Now, for the Intelletic system, I believe it has one wire that indicates the generator is running. (Note: It can even tell you it is running but you can actually have no power if the circuit breakers on the generator are in the off position. [Don't ask me why I know.] So, the one light is showing your generator is running.
Now, the 50 Amp LED light normally is not ON when your generator is running. My guess, the Intelletic is confused. (Hopefully you did not send a "spark" down the line from both shore power and generator on at the same time.) I would just turn off the batteries and turn them back on to reset your Intelletic system. (Or, you can pull the 5 Amp fuse on the Intelletic board but sometimes it is hard to reach.)
This help?

[Dr4Film]

Here is a link to the Power Line EMS manual in case you don't have one.

http://janeandjohn.org/docs/EMSmanual.pdf

The easiest thing to do first is a cold system reset to see if that corrects the display problem,

Next, I had a situation one time where my EMS display panel was giving me some erroneous displays. It ended up to be a defective Thin-Lite ballast over the kitchen sink.

Your ATS has noting to do with the EMS system. The EMS is actually downstream from your ATS.

Dr4Film ----- Richard

[John Hilley]

Originally Posted by dengraham

What Pusherman said is correct. If you turn OFF all the power the transfer switch will pull relay to the default Generator position. If you have power from both the shore power AND the generator; the transfer switch will also default to the Generator position. So, as stated if they are both powered (i.e., live) you are causing small "sparks" at the contacts are disconnected and connected from shore power to generator.
Now, for the Intelletic system, I believe it has one wire that indicates the generator is running. (Note: It can even tell you it is running but you can actually have no power if the circuit breakers on the generator are in the off position. [Don't ask me why I know.] So, the one light is showing your generator is running.
Now, the 50 Amp LED light normally is not ON when your generator is running. My guess, the Intelletic is confused. (Hopefully you did not send a "spark" down the line from both shore power and generator on at the same time.) I would just turn off the batteries and turn them back on to reset your Intelletic system. (Or, you can pull the 5 Amp fuse on the Intelletic board but sometimes it is hard to reach.)
This help?

Actually the transfer switch connects the shore power to the load center when the contactor coil isn't powered. When the generator starts, 120 vac goes to the contactor coil through a timer. The timer is usually a 30 second delay to allow the generator to come up to full speed before applying a load to it. When the 120 vac from the generator gets to the contactor coil it pulls in the contactor and connects the load center and generator together.

[Dr4Film]

Most transfer switches, well at least mine is, are built with the main relay in a default position and usually that is the shore power position.

When the generator is started, there is a delay allowing the generator time to spool up and stabilize, then the generator relay will kick in as the generator always takes priority even if you have the shore power connected. However, if you do that often, it's recommended to shut down all heavy loads to preserve the contacts in the ATS otherwise they will arc and eventually the ATS will not work correctly.

Dr4Film ----- Richard