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Amp draw


jacwjames
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I question why there is a difference on the Progressive Surge Protector display and the Intellitec EMS display. 

The Progressive system monitors both legs L1 & L2 and displays voltage and amperage. 

I believe the Intellitec just monitors the neutral to determine load on both legs. 

It seems like the Progressive displays higher amperage then the Intellitec.  Why is there a difference, I don't believe there is anything wired in between?  As an example, I am currently running both heatpump with low fan setting.  The Progressive display shows 15 amps on both L1 & L2.  The Intellitec shows 28 amps.  The EMS is letting both work.  I'm sure if the battery charger kicked in it would probably drop me out.  I don't believe the refrigerator is running now.

Seems petty but when you are plugged into a 30 amp service and need to control consumption it seems like if you are close to the 30 amp limit on the Intellitec you are probably the limit of the 30 amp service. 

Can someone explain the difference?

Thanks

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Is it a HW version? I know you can calibrate the display voltage back at the unit, I’ve done it because it was reading like 3volts higher than I was measuring. I would calibrate per their instruction and it was pretty easy. They eventually replaced the board because it wouldn’t stay. Don’t know if this relates to your issue but I’m not too confident with them anymore. I even had a code that said my Hertz were too high one time while up in MI

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On 11/22/2021 at 10:47 AM, jacwjames said:

I question why there is a difference on the Progressive Surge Protector display and the Intellitec EMS display. 

The Progressive system monitors both legs L1 & L2 and displays voltage and amperage. 

I believe the Intellitec just monitors the neutral to determine load on both legs. 

It seems like the Progressive displays higher amperage then the Intellitec.  Why is there a difference, I don't believe there is anything wired in between?  As an example, I am currently running both heatpump with low fan setting.  The Progressive display shows 15 amps on both L1 & L2.  The Intellitec shows 28 amps.  The EMS is letting both work.  I'm sure if the battery charger kicked in it would probably drop me out.  I don't believe the refrigerator is running now.

Seems petty but when you are plugged into a 30 amp service and need to control consumption it seems like if you are close to the 30 amp limit on the Intellitec you are probably the limit of the 30 amp service. 

Can someone explain the difference?

Thanks

The neutral only carries the difference between any unbalanced loads.

If you're drawing 30 amps from each of the 120v legs, your neutral will have zero current flow.
Just monitoring the neutral will not give an indication of load.

No IF the 50a outlet is incorrectly wired with both legs on the same phase, as some campgrounds have been reported to do, your neutral will carry the total current from BOTH legs, possibly up to 100amps, which will quickly overheat the conductor, damaging equipment and possibly starting a fire.

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6 minutes ago, dl_racing427 said:

IF the 50a outlet is incorrectly wired with both legs on the same phase, as some campgrounds have been reported to do, your neutral will carry the total current from BOTH legs, possibly up to 100amps, which will quickly overheat the conductor, damaging equipment and possibly starting a fire.

David, besides actually measuring L1-L2 voltage, do you know if Progressive EMS would catch it?

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This happens anywhere I'm plugged in, even at home & I know that wiring is right because I did it all myself. 

The Intellitec system has one load sensor that is measuring the neutral, it doesn't care which leg it is on.

I do have the HW50C progressive so it may need to be calibrated, another thing I'll worry about later.

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I have been round and round with Progressive on their displayed amperage. I have confirmed with multiple ammeters and inline ct coils inline with the coach power going to digital displays. I have narrowed down to a particular repeatable event that Progressive shrugs and tells me they don't know why. I have used 3 different 50amp top of the line Progressive surge protectors (HW50C ) that are plugged into shore power poles. I have also used one inline Progressive surge system with digital monitoring and they all exhibit the same anomaly. One leg of the Progressives shows an amp draw of approx 15amps higher than the ammeters and my inline ct coil/digital readouts. Early on in this journey because of the Progressive reading I removed Monaco's installed analog amp meters and installed the digital versions. I talked to Progressive several times and even went so far as to take pictures of the Progressive next to an ammeter connected directly to the shore power pole. I literally took the cover off of the pole so that I could clamp the meter onto the incoming legs of city power. One leg at a time of course. 

I do tend to chase things like this endlessly for the answer. 

I don't know/understand the reason and neither does Progressive but the phantom voltage only appears on the Progressive (all 4 of them) when my Xantrex (circa 2003) is bulk charging. Absorption and Float seem to read reliably on the Progressive meters. 

I do not believe that the HW50C can be calibrated as I was told that opening the outdoor version of the hardware will void their warranty. 

 

 

 

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On 11/24/2021 at 5:06 AM, Grampy OG said:

I don't know/understand the reason and neither does Progressive but the phantom voltage only appears on the Progressive (all 4 of them) when my Xantrex (circa 2003) is bulk charging. Absorption and Float seem to read reliably on the Progressive meters. 

 

 

 

Interesting post. Apparently there is some level of interference between the 2 units. The Xantrex could be the problem or both units could be contributing. Bulk charging means ramping up the voltage with maximum amps and then absorb begins to taper the amps. Perhaps the Progressive is not a RMS voltmeter?

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The basics: For 120/240 50A single phase shore power the neutral wire is the same size as the 2 hot wires and carries the DIFFERENCE of the amps on the two hots. The neutral cannot be used to display the total amps. This is the exact same power supplied to houses except that a house has a higher amp rating like 200A. For 20A and 30A circuits the hot and neutral carry the same amps. 

My Intellitec defaults to 30A when it detects 0V between the 2 hots and in that case a single sensor on the neutral can display the amps for 20A and 30A. It cannot determine the difference between 20A and 30A and hence requires me to push a button when on 20A. This is for load shedding on 20A and 30A. 

The NEC recommends limiting the power to 80% for sustained loads or 24A on a 30A circuit. And 2 ACs in hot weather will qualify. This is one reason why 30A plugs often show signs of overheating. 

Neither the Progressive or Intellitec units are calibrated so a display difference of a few amps is normal and consistent in price with more accurate and calibrated devices. 

Note: All bets are off for a miswired 50A circuit which is not common and in direct violation of the NEC code. But some CGs do so because it’s expensive to install 50A power.

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8 hours ago, W7BE_Bob said:

Interesting post. Apparently there is some level of interference between the 2 units. The Xantrex could be the problem or both units could be contributing. Bulk charging means ramping up the voltage with maximum amps and then absorb begins to taper the amps. Perhaps the Progressive is not a RMS voltmeter?

It is so perplexing because I have put the clamp-on ammeter literally 4 inches from the Progressive. It is so odd to me that theirs are the only meters that measure differently. In my case I have given up the chase and will honor it's ability to kill the surges and I will measure my amp draw without relying on their readouts. 

 

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