Minnie AMP draw

Steve77 · 02-16-2021, 07:40 AM

I had started another thread, but it was confusing as I stumbled through trying to figure out what was wrong.

My 2021 Minnie 2301BHS is supposed to be able to run two AC's on 30 amp service, see below promotional video from Winnebago. It is pretty clear.

https://youtu.be/OZFiOH4MkZc

Around 1:30 he starts talking about the dual AC running on 30 amps.

My problem is, my AC's are drawing more than 30 amps when they are on with nothing else on. I have a watchdog, and can watch the amp draw on my phone as I turn things on/off. I just had a brand new, dedicated 30 amp receptacle installed in my driveway. So I know the source is not the issue.

I have been in contact with Winnebago and they insist I should be able to run everything on 30 amps.

They said my AC max amp draws would be:

13,500 = 12.6 amps
15,000 = 12.9 amps

But watchdog is showing 14.5 each.

With nothing on = .5 amp draw
One AC steady cooling = 15 amp draw
Both AC steady cooling = 29.5 amp draw

They both run for a few minutes, then eventually they raise to 30.5 amps and the watchdog shuts everything down. This is with nothing else on.

They want me to bring trailer back to dealer, but I find it super unlikely that both brand new AC's are drawing more amps than they should?

Any ideas? Thanks

DavidM · 02-16-2021, 09:24 AM

"They said my AC max amp draws would be:

13,500 = 12.6 amps
15,000 = 12.9 amps"

"They" said wrong. Look at the manufacturer's spec sheet or get a clamp on AC ammeter and measure it. I bet it is at least 10% more than above, which is why your breaker is tripping.

David

Steve77 · 02-16-2021, 10:28 AM

Quote:

Originally Posted by DavidM

"They said my AC max amp draws would be:

13,500 = 12.6 amps
15,000 = 12.9 amps"

"They" said wrong. Look at the manufacturer's spec sheet or get a clamp on AC ammeter and measure it. I bet it is at least 10% more than above, which is why your breaker is tripping.

David

Hi David. "They" is Winnebago, sorry if that wasn't clear. I have been in contact with them about this issue.

The spec sheet is attached, I highlighted my model for the front AC. Compressor Rated Load Amps of 12.7. Do you then add the Fan RLA to that?

DavidM · 02-16-2021, 11:01 AM

Quote:

Originally Posted by Steve77

Hi David. "They" is Winnebago, sorry if that wasn't clear. I have been in contact with them about this issue.

The spec sheet is attached, I highlighted my model for the front AC. Compressor Rated Load Amps of 12.7. Do you then add the Fan RLA to that?

Yes, I knew you meant Winnebago. I guess I quoted they to be cute which obviously didin't work

But anyway, yes you do add compressor amps to fan amps to get the total amperage.. They were just reporting compressor amps which is why they were wrong and you were tripping the breaker.

As you note, it isn't worth taking it in just to prove them wrong.

If you routinely camp at sites with 50A service you can probably upgrade yours to 50 to keep from tripping the breaker. You would have to get a new 50A shore power cord and inlet socket for 50A. Then you would have to run new 8 gauge 2C+G cable from one leg of the 50A socket inside the trailer to the power panel. If there is a master breaker in the panel then you will have to upgrade it to 50A. The only tough part of this is running the wire. Sometimes it is near impossible to follow an existing route that was installed when the trailer was a bare frame.

Good luck!

David

Steve77 · 02-16-2021, 11:38 AM

Thanks David, I understand what you are saying, the only confusing part is the video I linked to. Did you watch it? That video is on Winnebago's website right now, its made by them too.

The video says, as clear as can be/plain English no interpretation or suggestion, that you can run both AC's on 30 amp service. They mention some "Energy Management System" that is what allows this to work. Talking with Winnebago, I showed them the video and they are saying, yes the video is correct, you should 100% be able to run both AC's on 30 amp.

Winnebago also told me the EMS is literally a transfer switch that shuts off power to the microwave.

This is one of the big reasons we bought this trailer - dual AC on 30 AMP service. So Winnebago is either bold face lying or something is not working correctly. I am trying to determine which and what to do about it.

I realize I can upgrade to 50 amp but its a brand new trailer and its 50/50 down here for sites that have 50 amp. And I just paid an electrician to install 30 amp plug, plus bought the 30 amp watchdog.

DavidM · 02-16-2021, 12:34 PM

I watched it. Pure BS. In addition to his false statement that you can run both A/Cs on 30A power, he said that once they are both running you can use the microwave and/or the water heater due to the EMS.

Running amps are much less than starting amps, but they add up to about 30 amps running for both. Add the microwave and the water heater and you are up to 50+ amps. There is NFW can you run all of that at once.

David

Old Navy · 02-16-2021, 12:53 PM

When I was shopping the Minnie line in 2020, 13.5K Single AC was "standard", and 15K was an option on ALL Minnies. Looking at the 2021 Minnie brochure, it looks like this has carried on to the new Minnies. I wonder if the Bedroom AC option and the 15K option are mutually exclusive? You would think the factory would know, but that isn't always the case.

For comparrison, I just walked out and ran my single 15K AC while plugged into a "kill-a-watt" type device, and the AC draw is 12.5A @ 118V. It could be the new "low profile" AC units on the 2021 models are less efficient than my 2020.

Steve77 · 02-16-2021, 01:51 PM

Quote:

Originally Posted by DavidM

I watched it. Pure BS. In addition to his false statement that you can run both A/Cs on 30A power, he said that once they are both running you can use the microwave and/or the water heater due to the EMS.

Running amps are much less than starting amps, but they add up to about 30 amps running for both. Add the microwave and the water heater and you are up to 50+ amps. There is NFW can you run all of that at once.

David

That video isn't saying you can run all that stuff at once, it is saying the energy management system will shut those things down if it needs the power for air conditioners. Load shedding. Which I am familiar with and more than OK with. It does, however, flat out say that you can run both AC's on 30 amp service.

If I could run both AC's on 30amp and nothing else, I would say....ok maybe the video was a little misleading. But that's not the case - I cant run both AC's at once on 30 amp under any circumstance. I wasnt under the impression I would be able to run both ac's, the microwave, the fridge, and the hot water heater all at once. I was under the impression I could put the fridge and water heater to gas, not use the microwave, and run the lights and both AC's on 30 amp service.

I hear what you are saying, but - I am just having a hard time believing an otherwise reputable / established company would engage in such blatant false advertising. Consumer protection laws are pretty strict and I just cant see them taking the risk - especially with something that involves electricity and fire hazard. Again, this isn't some YouTuber reviewing the trailer, this is a video produced and circulated by Winnebago itself. It is literally on their website under the Minnie trailer section.

Steve77 · 02-16-2021, 02:00 PM

Quote:

Originally Posted by Old Navy

When I was shopping the Minnie line in 2020, 13.5K Single AC was "standard", and 15K was an option on ALL Minnies. Looking at the 2021 Minnie brochure, it looks like this has carried on to the new Minnies. I wonder if the Bedroom AC option and the 15K option are mutually exclusive? You would think the factory would know, but that isn't always the case.

For comparrison, I just walked out and ran my single 15K AC while plugged into a "kill-a-watt" type device, and the AC draw is 12.5A @ 118V. It could be the new "low profile" AC units on the 2021 models are less efficient than my 2020.

I'm not sure. My model number on the main AC is 640315C75X but all the other 13.5 btu units on that table I attached (most are not the slim line models) have very similar amp draws. Both of my AC's seem to be running close to the max amp draw the entire time it is cooling. According to that sheet the RLA are 12.7 for compressor and 2.6 for fan 15.3 combined. Mine only goes below 14.5 when the compressor cycles off and it drops to like 2.5 amps with just the fan running. If mine were running while cooling at 12.5 I would probably be OK. But to have both of them, both brand new, drawing more amps than they should seems unlikely. Unless there is something about new AC's that would inherently make them draw more amps until they were broke in or something?

Steve77 · 02-16-2021, 02:16 PM

I actually just went out to paly with the AC's and write down the different amp draws. The bedroom AC by itself shut the watchdog down. When I switched it on it stayed over 50 amps for several seconds so there must be a problem with that AC, and maybe that will solve the issue.

With nothing on- .5 amps
With front AC only - 14.5 amps

So if the rear AC is the same as the front, that should be 28.5

Main lights add about .5 amp draw.

Steve77 · 03-10-2021, 09:12 AM

So the trailer has been at the dealership for weeks. They finally got to look at it this morning and just called and said there is nothing wrong with either AC...they have had them both running for over an hour. They said the problem was probably my EPO.

I think what is happening is they have it in the shade of the bay on a cool day (cool for here 75 degrees), where I had it in direct sun on a warm day (85 degrees). He said he understood what I was saying but the problem is if they cant get it to trip a breaker, Winnebago wont let them keep hunting.

The classic mechanic problem.

I asked him to put an amp meter on it and see what both AC's are drawing when both compressors are on. He is going to get back to me.

I know my EPO is probably less tolerant than a breaker is for overdraw, but a 30 amp breaker should trip around 31 amps right?

**creativepart** · 03-10-2021, 10:05 AM

Quote:

Originally Posted by Steve77

I know my EPO is probably less tolerant than a breaker is for overdraw, but a 30 amp breaker should trip around 31 amps right?

I've been told a 30-amp breaker is expected to continuously hold 80% of it's rated power in the US. Temperatures outside can effect this directly because a circuit breaker doesn't measure amperage... it measures temperature changes. A slight overage may cause the circuit to trip over time but a dead short may cause it to trip immediately due to the increased heat in the breaker the dead short creates. Electricians design circuits to not routinely exceed that 80% continuous limit.

I've been also told that the EMS on my motorhome watches electrical usage and it memorizes the most recent PRIOR amperage for each electrical device. Not the actual amperage at any given moment. And, that it doesn't have a database of what each electrical load should be... it just keeps track of what the latest draw has been in the past.

Lastly, my two A/C units use 28 amps of power when the compressors and fans are running. The EMS will not permit them to both run at the same time on 30 amp shore power. My RV's EMS generally tries to keep power usage at no more than 28 amps. It's working to keep you from blowing power pedestal breakers. Though it's not a super smart device and it does sometimes cause a power pedestal breaker to blow.

Morich · 03-10-2021, 10:20 AM

I understand what you are chasing and it is going to be a problem but don't get into too many other points like the temperature.
The outside temp only changes the amount of time the AC will run and how effective it will be at keeping you cool, not how much power each Ac will draw when running. Not beyond the obvious ideas that things work a bit different when hot but I would tend to not get involved in the temperature when testing.

Throwing in a bit different thinking, I see there might be times when the local power could push things that are running at near limits over into not running.
I have had experience in rural areas where there were lots of dairy farms and they tend to have less than the latest power control equipment. That combo meant we suddenly had power rectifiers tripping out at/near dawn for odd reasons that we had trouble pinning down until we set up equipment to monitor the AC power coming in and found it was swooping low at the time when folks with dairy farms turned on the milk coolers!
I fell out of the loop at that point as I was not part of the engineering group, just the "fix-it" group! But hanging around the local coffee shop, I did get rumors of the local power folks being very unhappy with the expense we caused them for the upgrade!

Some thoughts of how low voltage at your local level might change the way things run as low voltage does often lead to breakers tripping.

backtrack15 · 03-10-2021, 10:26 AM

Like Morich implied, my first thought was maybe you've got low voltage under that load at the house. Then I started pondering how hard Winnebago is willing to push this system. It definitely sounds like it is going to be something that works reliably only in the best of circumstances.

**creativepart** · 03-10-2021, 10:47 AM

I watched the video and it's misleading if not just plain wrong. When he talks about "that second A/C" and not have to turn things off is he saying that the 1st AC is also running it's compressor OR is he talking about the 2nd A/C only?

On 30-amp you can run one A/C AND the microwave OR the water heater OR the battery charger (on Bulk/Absorption). Those are not "ANDs" but "one OR the other."

It seems to me that this is what WBGO designed into the RV. This must be the reason the optional 2nd A/C is not on the thermostat and instead uses manual controls at the interior A/C unit.

When the living room A/C's compressor is running (not starting) and if my batteries are in Float and fully charged, my water heater is on propane and no one is using the microwave the EMS will sometimes attempt to start the bedroom A/C. And sometimes it succeeds for a while. However, if anyone uses the microwave one A/C will immediately shut down. It may or may not attempt a restart.

One of our favorite State Parks only has 30-amp service. It's only 100 miles from our home. So, in South Texas that means 95 to 103 degree days and 78 degree nights. We try not to go there in hot weather because the 30-amp service is not going to let both of our A/Cs run together enough to keep the temps inside the RV comfortable.

If I were Winnebago I would remove or amend that Video because it creates a false impression of the Travel Trailers true capabilities.

powercat_ras · 03-10-2021, 10:52 AM

Winnebago never puts 2 AC on 30 amp power box in their motorized RVs. I'm shocked that they are doing it in their non-motorized.

You may want to research other threads here and on IRV2 that describe how to upgrade to 50 amp power box and shore cable, or describe how to take the 2nd AC power feed to a plug you can connect to a separate 12 gauge power cord that can be fed from a different receptacle.

Standard practice would be to feed a 13,500 or larger RV AC from a 20 amp dedicated circuit and breaker, but it works running from a dedicated 15 amp breaker in most cases, in particular for 13.5 K units.

Steve77 · 03-10-2021, 06:16 PM

I appreciate what everyone is saying, and I agree 2 acs should not be able to run on 30 amp service under normal circumstances... Let alone everything else in the camper.

The problem is... And what my issue is... Is that video dosent hint or suggest you might be able to run 2 acs on 30 amp.. It flat out says, specifically, that you can. He mentions the reason you are able to do so is because of their new energy managemt system.

This is the main reason we bought this trailer.... Because normally 2 acs can't run on 30 amp service. But 2 acs is a must in FL and on 30 amp is a miricle.

I called winnebago before I purchased and while they could not not tell me exactly what the energy management system was (because, she said, it was so new and no one there knew), they said 100% I could run both acs on 30 amp. As a matter of fact she said if it wasn't possible they would have to put a switch to select which ac to run. After multiple calls and emails after purchase explaining what is happening winnebago is still insisting I should be able to run both acs.

So where I'm at isnt really can I do it, or how can I make it work... It's what winnebago is going to do to make it right.

Steve77 · 03-12-2021, 02:40 PM

So I picked trailer up today, they still had not heard back from Winnebago.

Here is the report from dealer...both AC's amp draw 29 amps. Again, that is in shaded bay on cool (75 deg) day. With nothing else on. So this replicates my findings, so we shall wait and see what Winnebago says.

Mbconnolly · 09-14-2022, 10:15 AM

Quote:

Originally Posted by Steve77

So I picked trailer up today, they still had not heard back from Winnebago.

Here is the report from dealer...both AC's amp draw 29 amps. Again, that is in shaded bay on cool (75 deg) day. With nothing else on. So this replicates my findings, so we shall wait and see what Winnebago says.

Steve,

I just posted this exact same question and issue to this site yesterday. Someone forwarded me this thread that you started. Our RV is currently at the dealer's to "fix" this issue, under warranty. How did Winnebago respond to your issue? I didn't see a resolution summary and am incredibly curious, since my husband and I are following the same path. We also noted that Winnebago upgraded our model to 50 amp approximately 2 months after we bought our 30 amp. :(

BobC · 09-14-2022, 04:18 PM

I also suspect that voltage is the culprit. The 29.5A rating from Winnebago is going to be based on 120V. 29.5A at 120V = 29.5A x 120V = 3,540 Watts.

Per the National Electrical Code (NEC), the acceptable voltage for a 120V nominal service is 114V - 126V. The actual amp range, therefore can range from 3,450W/126V = 28.1A to 3,540W/114V = 31.0A. Everything else being equal, the dealer's reading of 29A could relate to a supply voltage of 122V. And remember, the 29.5A spec, isn't going to be spot on for every A/C unit.

Note that you need to measure your supply voltage at inside your trailer since the resistance of your extension cord(s) can reduce the voltage below that at your supply outlet.

In any case, assuming everything is apples to apples, a 29.5 amp draw on a 120V/30A supply is cutting things way too close, especially when you take into account the high variability of power quality in RV campgrounds.

Personally, I'd just run one A/C at a time, alternating them until you're at a comfortable temperature and then running the one that's closest to where you are. This will also give you the overhead to watch TV, etc.

Note that I have a similar situation with my 2002 Coleman basement air. Although it's a single unit, it has two compressors. They'll both operate on 30A under perfect conditions but not always.