15K Coleman Mach AC-EMS shuts down power to RV

ENJ · 07-28-2022, 08:14 AM

New issue with a stock Cougar 25RES with one AC. AC has been working fine for the last 2 years when used at electrical camp sites (installed the SoftStart shortly after purchasing the RV). This past week, we went dry camping for a change on a hot (95 F) day and set up 2 Honda EU2200i generators in parallel for electrical. Refrig and hot water were on propane.

All RV electrical worked, including the AC fan on high. BUT...when i turned on the AC to cool, the EMS (Surge Guard 34951) shut down electrical to the RV after less than a minute when the AC tried to start.

The only change to the system was adding the "Customer Satisfaction Campaign" "End of Line (EOL) resistor" from Keystone from May 5 ,2022 to the AC. The circuit box looks fine. This shouldn't be the issue??

We have an full service campsite in a couple of weeks, so I can try using the AC on a 30 amp service rather than the 2 generator set up. But...in the meantime, any suggestions on what may be causing such an issue would be welcomed.

hawghauler · 07-28-2022, 08:26 AM

I'm not a rocket surgeon but I stayed at a holiday in once so based on what you've said I would remove the recently installed resistor and see what that does

I don't understand the eol resistor on a singke unit system it's redundant

Javi · 07-28-2022, 08:28 AM

Quote:

Originally Posted by ENJ

New issue with a stock Cougar 25RES with one AC. AC has been working fine for the last 2 years when used at electrical camp sites (installed the SoftStart shortly after purchasing the RV). This past week, we went dry camping for a change on a hot (95 F) day and set up 2 Honda EU2200i generators in parallel for electrical. Refrig and hot water were on propane.

All RV electrical worked, including the AC fan on high. BUT...when i turned on the AC to cool, the EMS (Surge Guard 34951) shut down electrical to the RV after less than a minute when the AC tried to start.

The only change to the system was adding the "Customer Satisfaction Campaign" "End of Line (EOL) resistor" from Keystone from May 5 ,2022 to the AC. The circuit box looks fine. This shouldn't be the issue??

We have an full service campsite in a couple of weeks, so I can try using the AC on a 30 amp service rather than the 2 generator set up. But...in the meantime, any suggestions on what may be causing such an issue would be welcomed.

Are you using a ground bounding plug on both gensets.. if not.. you must

bobbecky · 07-28-2022, 10:59 AM

The EOL resistor is strictly for the inCommand communication system, so would not have anything to do with your EMS. The most likely cause of the shutdown is the lack of the bonding plug, like Javi noted. Your Honda's don't have the neutral and the ground tied together like you would see in a metered electric panel, and most EMS devices look for that connection and shut down if it's not there. You can make your own or just buy one. https://www.amazon.com/generator-bon...r+bonding+plug

ENJ · 07-28-2022, 11:46 AM

Actually, the reason I bought the SoftStart- I follow Mike Sokol's articles. I have been using the grounding plug from the beginning based on the setup described by Mike in his Nov 21, 2019 article "RVelectricity: Parallel generator neutral bonding". There is a nice diagram on the setup for Honda generators, which I follow to a "T".

I will try removing the EOL add on sent from Keystone based on their advisory that Keystone said was needed on a one AC system.

Any other suggestions out there? Does it maybe have something to do with the In-Command- does it need to be reset/rebooted?

**flybouy** · 07-28-2022, 01:38 PM

I don't see the correlation between the EOL and the EMS. The EMS will shut down power for incoming power issues. The bonding plug on both generators or low voltage would be my suspision. I didn't look up the EMS model so does it indicate the fualt ? Since the EMS didn't disconnect until the compressor came on line would lead me to think low voltage. Maybe an issue with one of the generators or the parallel connection?

Are you camping at an elevation over 2k?

**sourdough** · 07-28-2022, 01:49 PM

You've got a 34951 Surge Guard which is 50A which I have as well. When it shut you down what did the display say the fault was?

Also you are using adapters etc. which Southwire warns about. I don't think it's anything to do with In Command or the trailer. I would be looking at what's happening when it shuts down and the power being provided. The link below gives you how it tells you the various faults it sees.

https://rvpower.southwire.com/wp-con...n-Sheet225.pdf

ENJ · 07-28-2022, 02:42 PM

Thanks for the input. I am using the 50 to 30 amp CAMCO heavy duty dogbone for the connection from generators to the 50 amp EMS. I am using just the one neutral grounding plug as Mike Sokol- as 2 (one on each) defeats the purpose. The elevation was 500 feet.

The display went through the 7 or so seconds countdown before going to power on (at 125 volt at 60hz). I then turned on the AC fan only and it worked great. Then when I turned the AC was on, the current was still on with the fan, but no AC cool air. After about 60 seconds the EMS went from power on to "caution when flashing" red- power off to the RV. The readout showed <100 volts (low voltage)- and the EMS started going through the 128 second restart countdown. The surge protection light is still on.

At that point- hoping to get advise from the forum before taking the step of going in to the Keystone dealer for extended warranty- we all know what that means (not much help at all).

Thanks again for any advice.

**sourdough** · 07-28-2022, 02:50 PM

If it was telling you it was getting less than 100 volts that's why it shut down and that won't be the trailer or Keystone. The power/voltage is coming from the generator(s) plus the airconditioner works fine on commercial power. I would be sorting out the generator problem.

**flybouy** · 07-28-2022, 02:52 PM

I would try it on a 50 amp supply before "taking it in". If it works OK then you know the issue is either with the generator or the adapter.

ENJ · 07-28-2022, 03:21 PM

Thanks all. I will be able to try a campground hookup in a couple of weeks.

RollaMo · 07-28-2022, 03:52 PM

Quote:

Originally Posted by ENJ

After about 60 seconds the EMS went from power on to "caution when flashing" red- power off to the RV.
The readout showed <100 volts (low voltage)- and the EMS started going through the 128 second restart countdown. The surge protection light is still on.

At that point- hoping to get advise from the forum before taking the step of going in to the Keystone dealer for extended warranty- we all know what that means (not much help at all).

Thanks again for any advice.

Sounds like the EMS did exactly what it was supposed to do.
< 100 volts is not good, and will damage your A/C compressor.

This really isn't a Keystone or warranty issue at all.

**JRTJH** · 07-28-2022, 04:16 PM

Quote:

Originally Posted by ENJ

New issue with a stock Cougar 25RES with one AC. AC has been working fine for the last 2 years when used at electrical camp sites (installed the SoftStart shortly after purchasing the RV). This past week, we went dry camping for a change on a hot (95 F) day and set up 2 Honda EU2200i generators in parallel for electrical. Refrig and hot water were on propane.

All RV electrical worked, including the AC fan on high. BUT...when i turned on the AC to cool, the EMS (Surge Guard 34951) shut down electrical to the RV after less than a minute when the AC tried to start.

The only change to the system was adding the "Customer Satisfaction Campaign" "End of Line (EOL) resistor" from Keystone from May 5 ,2022 to the AC. The circuit box looks fine. This shouldn't be the issue??

We have an full service campsite in a couple of weeks, so I can try using the AC on a 30 amp service rather than the 2 generator set up. But...in the meantime, any suggestions on what may be causing such an issue would be welcomed.

Let's do some math:
Honda 2200i generators are rated 2200 watts surge/1800 watts sustained power. At 120 VAC, 1800 watts is 15 amps.

Now, when connected in parallel, the generators will produce 15 amps PLUS 15 amps. That "adds up to 30 amps, but how is the 30/50 amp adapter distributing it? If it's connecting the "single 30 amp source" to two separate legs on the 50 amp side, then if one side (say L1) is drawing 18 amps, then there's only 12 amps left for L2. That said, if the 30/50 amp adapter is equally dividing the 30 amp source between L1 and L2, and if your converter and air conditioner are both on the same leg, then you could be creating a "significant load" on that leg, pulling down the generator's parallel device, and creating a low voltage condition which is shutting down your EMS.

As was posted above, if the trailer system operates properly on shore power, then it's NOT the trailer that's causing the problem. It's in the generator system "somewhere"... I'd suspect either the parallel wiring or the dogbone wiring.

All that said, I'm still not certain how your generators are set up. The discussion was that BOTH generators require a bonding plug. Then with comments pertaining to being set up "just like the video" and "the same as Sokol's articles"... So, are you using ONE or TWO bonding plugs?????

ENJ · 07-28-2022, 05:24 PM

Using just one bonding plug - on the generator that has the dogbone connected to the EMS. Are you saying that both generators in the parallel setup should have bonding plugs? Please let me know when you get a chance.

Here is the link to the article.
https://www.rvtravel.com/rvelectrici...rator-rvt-923/

Is there a way to troubleshoot the output of the gen parallel set up?

**JRTJH** · 07-28-2022, 05:44 PM

Quote:

Originally Posted by ENJ

Using just one bonding plug - on the generator that has the dogbone connected to the EMS. Are you saying that both generators in the parallel setup should have bonding plugs? Please let me know when you get a chance.

Here is the link to the article.
https://www.rvtravel.com/rvelectrici...rator-rvt-923/

Is there a way to troubleshoot the output of the gen parallel set up?

If you are using the "4 pin 30 amp to 50 amp RV dogbone" like the one in the article, then essentially, what you're doing is applying 1800 watts (15 amps) to L1 and 1800 watts to L2. So while it's "true in the literal sense" that you're applying 30 amps to your trailer shore cable, in reality, what you're doing is applying 15 amps to each leg. The way your generators are wired through the parallel cable connections provides "generator 1 output to L1" and "generator 2 output to L2". So, like I posted previously, if your air conditioner and the converter are both on the same leg, then with the converter pulling 4 amps or 5 amps, there's only 10 or 11 amps "left over". When the air conditioner tries to start, with that "maximum 1800 available watts with 600 of those watts being used by the converter" you probably are "pulling the voltage down so much that the generator is bogging down, but the EMS is shutting power down before the generator circuit breaker opens to shut the generator down....

Essentially, I'd suspect that you're "operating the generators at the upper extreme capacity" and the EMS is sensing the voltage drop "just before the generator shuts down"....

If your trailer works on a 50 amp campground pedestal with no problems, then I'd say that the issue is the "generator setup working at the top of it's capacity and the EMS doing it's job properly"....

Solution: Make sure the converter and the air conditioner are on separate legs on the trailer power center and/or get larger generators.....

BUT: Before you buy or replace anything, I'd urge you to confirm that everything works like it's supposed to on a 50 amp campground pedestal. My guess is that it will work "perfectly" and the EMS will remain "happy".....

jxnbbl · 07-29-2022, 04:34 AM

In your OP, you don't mention the converter.

In addition to the other posts when I do something like this (small generator hookup)...I only use one 2500 champion. I ensure that the only item using that power is the target AC...via the circuit breakers. Did you turn OFF the converter? That will most definitely push you over the edge in this situation on startup as it is pulling amps prior to the AC compressor turning on (even in ramp up with softstart).

In my case, I have solar and my batteries are for the most part always topped off.

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