Intellitec 900 EMS

[Laura & Charles]

Had an issue, pretty sure it?s not resolved. On three different 50 amp pedestals, last one tested as ?good? by mobile RV repair service, all controlled appliances did not work, all non-controlled appliances and outlets had 120 volts. The display panel displayed the circling lines where it normally displays load in amps and service source displayed 30 amps. None of the lights indicating power available by appliance were lit. (On generator, exact same except service source displayed Gen Set instead of 30 amps.)
I tried resetting by turning off shore power and disconnecting batteries (and even pulled the fuse feeding the 12 volts to the EMS. No change.
Today, had a mobile RV repair guy come. (Yes, even on Labor Day. Took pity on us stuck with no AC in Texas... well , that and our willingness to break out the check book ?). He metered everything and checked connections... issue remained. Then, as he was writing things up with a plan to rush order a new EMS, seemingly out of the blue,  the display panel source changed to 50 amps and all the appliance ?power available? lights were lit. The load display is not displaying anything , no amps, not even the circling lines. The fridge switched to electric, both ACs are blowing cold, and the washer/drier acts like it will work (its controls light up, before it was dead.)
I really doubt the problem is resolved. Mobile repair guy says he?ll check with us in the morning and, if things remain as is, he recommends replacing the load sensor.  Since load is not displaying, I?m inclined to agree with his approach.
Anybody have same or similar experience?  Suggestions?

 

[Gary RV_Wizard]

It doesn't display amps when on 50A shore power - the amps display should be blank. Only 30A can measure and display amps.

 

[Laura & Charles]

Holy crap... I guess I just never paid much attention unless on 30 amps or generator..?

With that in mind, I?m going to make sure the gauge is working and, presuming it is, will tell him not to order that sensor. I still don?t think the issue is fixed, but it cannot be diagnosed if it?s not happening. I really would like to address it rather than just wait for it to reappear. We?re hosting a tailgate at AT&T stadium for the OSU v TCU game 9/15 (why we headed south a bit earlier than we would have otherwise)... I suppose the surest way to have the issue show itself again is to invite a bunch of people over for a mid-September party in Texas. ?

 

[John From Detroit]

WHY it does not show amps when plugged into 50..

It measures the current on the NEUTRAL wire WHen you are on 30 amps some current passes through the L-1 HOT.. Some the L2-Hot  ALL of it passes through the neutral

WHen on Generator.. Most RV generators are 120 volt only not 120/240 so see the above and once again ALL the current travels on the Neutral.

When on 50 the current on the neutral is the DIFFERENCE between L-1 and L-2  So its meaningless to measure current on the neutral.

in fact if L-1 and L-2 are perfectly balanced (next to impossible) there will be no current in the neutral.

 

[Gary RV_Wizard]

Gotta agree that nothing has been resolved yet, and there are obscure possibilities I can think of that might give such flaky results.  One is a a poor 12v wire connection at the EMS backpanel.  Another is a poor quality neutral wire connection in the shore cord, the outside power outlet, or the RV's own load center, but the fact that using the genset didn't change anything mitigates against that. A third might be a intermittent or poor data cable connection to the remote display.  I've seen reports that a bad data cable or faulty remote gave some bizarre symptoms, but the diagnosis was never conclusive (except that things began working after fiddling with the remote data cable).

 

[Laura & Charles]

The display worked fine on 30 amps (thx for the backstory, John).  So I cancelled the parts order and am awaiting for the problem to show itself again.  Good news is I?m awaiting in AC comfort.  Thanks for giving it some thought!!!  Intermittent problems are the worst!