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Smart EMS Load Meter?


tmw188
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Ok here’s one for you smart guys here. So I brought the coach home this afternoon and I’m plugged into 50amp at the house, preparing for our trip to FL. The outdoor temp is 20 and I have the electric fire place on low and a Dyson portable heater on low and plugged into the hall vanity area and the block heater on. So after a couple hrs I went out to check on things, feel the cords and stuff. I looked at the load meter and it was showing 9amps and I thought wow that seems low? Both heaters were producing heat and the block heater is on too? I shut down the Dyson heater and the meter jumped up to 21 amps? I then went and turned off the fireplace and it went back down to 9amps. I then went over and turned off the block htr and it was at 1amp and the charger was at float charge. This unexplainable to me. I don’t want this to turn into a 50 post thread but if there is a logical answer or guess I would love to hear it. 

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41 minutes ago, 96 EVO said:

Hmmm.

Do you have a surge protector that displays amps ?

No I don’t it’s this meter although this display is not modeling my issue. 

 

30 minutes ago, JDCrow said:

Bro we are bored, what’s wrong with chatting for 50+ posts ?😂

Don’t wanna make momma mad on Christmas

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Edited by tmw188
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It’s been since May since we’ve actually been able to use it and now it’s refreshing my memory that the only time I’ve seen it on is when the Gen is on or I’m on something less than 50a. That display wasn’t working when I bought it two yrs ago and with the help of Dr4Film I got it wire back to the way it was suppose to be and it worked. Someone had bypassed it for some reason and we had our doubts it it would even work once we wired it back up, but it did. 

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An EMS will typically show the current on the neutral line which is why it usually disables the display when connected to 50amp.  If your is showing amps and you really have 50 amps 220v service, then my guess is that it is showing the neutral amps, if you pull exactly 20amps from each leg, your neutral current should be zero, and if you shut off one of the 20amp legs, then your amps would jump to 20 on the neutral.

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Ya I thought about doing that while lying in bed last night. I will check the power from each phase once I get the slide out and the bed out of the way. I never had that display reading anything while plugged in at home before. Like you said I shouldn’t be seeing anything. 

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You need to sort out the reason for the EMS showing that you are on 30-amp shore power if you are on 50-amp shore power first.

I would not trust what the meter says or amps you are drawing until that is determined.

Also, as others have stated, when on 50-amp shore power the amp display is blank.

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7 hours ago, Harold said:

An EMS will typically show the current on the neutral line which is why it usually disables the display when connected to 50amp.  If your is showing amps and you really have 50 amps 220v service, then my guess is that it is showing the neutral amps, if you pull exactly 20amps from each leg, your neutral current should be zero, and if you shut off one of the 20amp legs, then your amps would jump to 20 on the neutral.

It the EMS a is connected to a 50 Amp service and that is a LEGITIMATE 230  VAC (you can measure 230 volts between Line 1 & Line 2), then the 50 Amp light will be ON and there will be NO amperage on the display.  The system will NOT be doing any load shedding…..so basically the EMS is just in a standby mode.

NOW, since he has a 7.5 or maybe 8.0 Generator, it is a TWO line generator.  However it as a dual pole 35 Amp breaker.  Line 1 and Line 2 are 115 VAC, but they are IN PHASE.  So, if you measure the L1 to L2 voltage, you get ZERO.  A conventional 50 A 230 VAC circuit has Line 1 out of phase with Line 2.  Using an In Phase generator will display the neutral amps…..as stated.  But there is only ONE Neutral.  So the Neutral is the SUM of the two line.  So, technically, you could see 70 amps (35 + 35) if you had the system fully loaded. The #6 wire is rated around 60 amps or so, therefore the neutral is overloaded.

If you have a 230 VAC (10K or higher) Generator, then the Neutral is the algebraic SUM of the Line 1 and Line 2 currents.  In a balanced condition, where you are loading, say 25 amps on BOTH Line 1 & Line 2, then both of them are constantly reversing phases…..so the sum of the currents is ZERO.  If it was a 30A load and a 10 A load, the Algebraic sum would be 20.  BUT, the EMS a meter is switched OFF….when the voltage between Line 1 & Line 2 is 230 Volts.

Bottom line….

The EMS ain’t reading 230 VAC so, the EMS thinks…..this is an IN PHASE service….so, I assume it is 30 Amps.  In the picture, the 20 amp light is on,  you can toggle, assuming the remote works, between the 20 and 30, so, if it is a 30 A service, it should be toggled to the 30 amp.

Comments about surge protectors and such have to be made with knowledge of what they will display.

The first step is to measure the voltage at the “receptacle”.  Measure from L1 - L2.  MUST be in the 220 - 240 range.  If ZERO, the it is a FAKE 50 amp and the EMS knows that….and is displaying what is going on.  Then you measure BOTH L1 and L2 to BOTH Ground and Neutral.  That voltage MUST Abe in the 110 - 120 range.  That means that there is NO OPEN NEUTRAL ( a condition that will kill the devices like AC’s and TV’s)….and that you have a Bonded Neutral to Ground with is required by the NEC and the RVIA electrical specifications.

NOW….assuming that is all to code and correct, then the EMS a is in a Funk..  The way to reset it is to Turin OFF or unplug the Shore and NOT run the Genny.  Remove the 3 pigtails or connectors from the EMS Board and also the 3 amp fuse.  Wait a few minutes.  Replace the fuse and reconnect the pigtails or wiring looms.  Then apply power.  The 50 amp service, which was measured and was correct, will “supply” 220-240 VAC to the two Line connections.  Then the EMS will “say”….all is well….nothing to see here” and display the 50 amp light and the green lights on the side….

Using the Genny, then the 30 amp light should be on and the current draw or the SUM of both lines….and the 30A light should be toggled on.

That is the ONLY away to  properly test and trouble shoot it.  .  now if the Upstream or plug in surge protector has a meter or display that gives you the SAME reading or status as the voltage testing, it can be used.  BUT that assumes that the surge suppressor has that capability and can be used in lieu of a VOM.

That needs to be done….Otherwise, one is chasing a ghost

10 hours ago, tmw188 said:

I do have the refrigerator and water htr off, but not sure if it’s in that load Ctr? I’ll look tomorrow first thing. 

ALL THE BREAKERS on the main panel must be ON.  The EMS gets cranky if one or more is off.  Often times, it must be reset after that.  See my other post….

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I truly have gotten that yes in the past I have never had a display while plugged in at home. It should be easy for me to determine after looking at the breakers and checking power coming in for the problem. If I would have remembered that I would have waited before posting.🤦🏻‍♂️ Yesterday while in storage I had the gen running to warm things up before starting and became use to looking at the meter, then once home I continued to monitor the meter when in fact it shouldn’t have given me any info. 

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  • Solution

Yep that’s what it was! The washer/dryer breaker I had off. I knew after reading all the suggestions that it had to be something like that because it never displayed while home before. Thanks for all the suggestions from you guys. Amazing how you start forgetting some things after being away a little while. We had a flood here over the summer and it was nonstop work for two mo. Fortunately I got my FASS Pump finished just weeks before all that. 

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Edited by tmw188
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And now you know how much various devices draw.

Your system was load shedding as it is designed most likely. That dryer breaker seems to catch someone, including me once in awhile. 

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