Power management problems

coffeesnob · 08-27-2013, 05:39 PM

My coach is rigged with a power management system that enables me to operate on 50/30/20 amps or a 5500w generator. I am currently plugged into a 50amp outlet and my management panel should indicate that 50amps are available. For some unknown reason it will only show 30amps. The auto switch is working and when I run the generator it does indicate as much. I am getting full voltage but cant figure out how to check the actual amperage available. Can anyone direct me on which way to go?
Any help would be greatly appreciated.

jesilvas · 08-27-2013, 06:06 PM

Are you getting 120V on both incoming legs?

DancinCampers · 08-27-2013, 06:42 PM

Check all your 120v breakers, make sure they are on.

Hikerdogs · 08-28-2013, 05:25 PM

Quote:

Originally Posted by jesilvas

Are you getting 120V on both incoming legs?

I agree. It sounds like only 1 leg is hot. There could be a bad connection at the power post or the transfer switch. I would unplug from the power post and check each leg of the socket to ground with a multimeter. If everything is ok there remove the cover from the transfer switch plug in again and make the same tests.

grtharris · 08-28-2013, 07:33 PM

The EMS is looking for 240VAC to sense that you are connected to a 50AMP service. If the service is not 240 at the post the EMS will not switch to 50amps.
You should check the power at the post for the correct 240 and be sure and check all of the circuit breakers. The water heater circuit breaker is one of the legs the EMS is checking. There was a very long thread a couple of months ago with the same problem and he had turned off the water heater breaker.

middleman210 · 08-28-2013, 07:54 PM

Also in some older areas they have what is called high eg ground which is when one of the feeder legs are actually grounded by design. This would show up as a 120 volt circuit on your panel.

Dr4Film · 08-28-2013, 08:10 PM

Make sure that your circuit breakers on your Inverter/Charger are not in the tripped position. I suspect maybe one of them has been tripped.

Remember that all 120 VAC goes through your Inverter and its acting as a "Pass-through" device. If one CB is tripped than you will only get one side.

Dr4Film ----- Richard

coffeesnob · 08-29-2013, 08:34 AM

Well gang, I certainly appreciate all your imput and have done everything that has been suggested. I am getting 120/240volts both at the power pole and through the transfer switch to the circuit panel. I have tested all the grounds for continuity and stray current, I've tested each circuit breaker, I have measured the actual amperage being used and it measures the same as being displayed. So I can find no problem with the system other than a display. But...it doesn't make good sense. I have found where the unit measures the amperage being used, but where does it know or how does it know the available amperage?
Again I respectfully seek the wisdom of my fellow campers.

wa8yxm · 08-29-2013, 09:07 AM

Disregarding the safety ground which,in theory, should carry no current anyway, 50 amp service looks like this

1--120v--N--120v--2
1 - - - - 240 v - - - 2

As you can see there is 120 volt either leg to neutral but 240 across the two legs.

Some parks, however, did not feel like burying all new cable so they just put a 50 amp outlet on what used to be a 30 amp line.

Thus you get

1 - 120 - N - 120 - 2
1 - - - - zero - - - - 2

Your energy manager sees this it assumes you are plugged into 30 amp with a dog bone, cause that is exactly how they are wired.

To confirm you need a mulit meter that can measure the voltage ACROSS the two sides of the 50 amp outlet.

The outlet lines are as follows (disregard periods)
. . . |N
1| . . . . |2
. . . G

Throught this post 1 means "Leg 1" 2 means Leg 2 (Though they are interchancable) N is Neutral and the G on the plug diagram is the safety ground.

1, 2 and N are flat slots, G is round or "U" shaped.

NoMoreAZ · 08-29-2013, 09:25 AM

Quote:

Originally Posted by Dr4Film

Make sure that your circuit breakers on your Inverter/Charger are not in the tripped position. I suspect maybe one of them has been tripped.

Remember that all 120 VAC goes through your Inverter and its acting as a "Pass-through" device. If one CB is tripped than you will only get one side.

Dr4Film ----- Richard

Not true on the MH in question. Inverter/Charger is 30 amps out only. The hot water heater, A/C compressor(s), and washer/dryer (if any) are wired outside the Inverter/Charger.

DancinCampers · 08-29-2013, 09:34 AM

You might try resetting the unit by removing the fuse on the circuit board.

The unit doesn't know how many amps are available, but is programmed. When it recognizes a 50 amp circuit it will not shed loads. When set to 30 or 20 amps, will shed to stay below those limits.

Try turning everything on and see if it sheds or not to stay below 30 amps.

NoMoreAZ · 08-29-2013, 09:55 AM

Quote:

Originally Posted by coffeesnob

Well gang, I certainly appreciate all your imput and have done everything that has been suggested. I am getting 120/240volts both at the power pole and through the transfer switch to the circuit panel. I have tested all the grounds for continuity and stray current, I've tested each circuit breaker, I have measured the actual amperage being used and it measures the same as being displayed. So I can find no problem with the system other than a display. But...it doesn't make good sense. I have found where the unit measures the amperage being used, but where does it know or how does it know the available amperage?
Again I respectfully seek the wisdom of my fellow campers.

As other folks have said, the Intelletic Power Line EMS detects voltage in a certain configuration to determine if you have "50 amps". Your Intellitec panel does not display the amperage when plugged into "50 amps". Since you say something is displayed, your system thinks "30 amps".

Has the Intellitec section of the manual included in your owners packet been helpful?

Are you measuring the AC current with a clamp-on ammeter?

Dr4Film · 08-29-2013, 10:03 AM

Quote:

Originally Posted by coffeesnob

I have found where the unit measures the amperage being used, but where does it know or how does it know the available amperage?
Again I respectfully seek the wisdom of my fellow campers.

You haven't posted what EMS system your coach is using but here is what Intellitec uses to measure the incoming amps to determine what mode to put it in, 50 or 30. It is located behind the EMS panel.

Intellitec Current Sensor 50 EMS PN 00 00703 000 | eBay

Dr4Film ----- Richard

grtharris · 08-30-2013, 06:40 AM

EMS mode is control by sensing the incoming voltage. The current sensing coil is on the neutral leg and will not give a total current reading when connected to 50amp/240vac and so the amp reading is blacked out.
Here is the other thread with a EMS problem.
http://www.irv2.com/forums/f101/50-a...cy-166300.html

D Lindy · 08-30-2013, 08:13 AM

I don't know about your PMS but with mine I have to physically select on the control panel what amp system i.e. 20, 30 or 50Amps I want he coach to operate on.

wa8yxm · 08-30-2013, 09:50 AM

I see I was a post late with my earlier post (has to do with the way I read this forum)

One other possibility is a blown fuse inside the EMS unit. this does happen.. Sadly I don't have that unit so can not tell you which fuse.

wa8yxm · 08-30-2013, 09:51 AM

Oh, and for the person who said "All 120 volt goes through the inverter"

Not true, I know of not even one motor home where this is true... Though much of the 120 volt goes through the inverter on my rig, and many others. Air Conditioners are normally wired in prior to the inverter, likewise the water heater and fridge.

coffeesnob · 08-30-2013, 12:52 PM

I am totally confused now. I have gone back over every circuit from the circuit panel to the power pole through the transfer switch and into the circuit breakers in the coach. I have 120v every where that calls for it and I have 240v everywhere that it is required. I have gone through the installation manual and the trouble shooting guide and all the tests are negative. I have a power line 2004 ems. Apparently the system is not recognizing the 240v although it is there. All the tests on the control module reveal that it is working as designed, however there are 4 resistors? on the top of the control module next to the dip switches that appear to be burned. When I touched the board one of the resistors fell off and I got a mild shock ( low voltage ).
At this time I am convinced that the control module is defective. What do you all think?
Another Question......I am suppose to have a 600watt inverter on board. Using the wiring diagrams and the service manuals, I cannot locate it anywhere. My coach is a 2006 Voyage 36M. Does anyone know where the inverter is. I have a remote on off switch on the display board also.
Have I totally confused you all as I have myself?

jesilvas · 08-30-2013, 01:15 PM

If you test at the relays for the EMS board, you should have 120V on both contacts for the relays to receive and feed power. But I'm with you; bad board.

Dr4Film · 08-30-2013, 01:43 PM

If you have a HOT burnt board with components falling off, remove the board and replace it with a new one.

Or you can replace the entire board and display with an upgraded EMS system as the displays are matched to the board.

I bought my board and display on eBay.

There is also a tech company that handles all of the technical concerns for Intellitec that may help you with some of your questions.

M&M Electroninc Repair

Mark Bayus plus the other persons name that answers the phone is Chris.

419-965-2662

www.mmelectronincrepair.com

Dr4Film ----- Richard