Why is Intellitec EMS load shedding?

[goldymar]

Hey all,

My 2000 Adventurer 32V must still be acclimating to its new life in the desert. The AC runs great until late afternoon, when the energy management system starts load shedding. With compressor#2 shut off, its gets pretty toasty. I don't really know what is happening, but my guess is something getting too hot. Does the EMS also do thermal management? The electrical loads are <20, so that's not the issue.

Help! Before my wife gets cooked!

[SarahW]

Hello and welcome. I have never heard of the Intellitec EMS handling any thermal management. (But that doesn't mean it doesn't. ) So there are no other loads on the system... laundry, microwave, etc?

Is your EMS original to your RV? Some friends have recently had their Intellitec fail and needed replacing in their 2007 RV. Hope that's not the problem for you!!

[Wayne M]

I would start with the pedestal. Do you have a surge protector installed? Can you see what the Amp draw is on each leg?

[Oldchinahand]

Goldymar

Wayne and SarahW make some good points. Segueing off that, looking at your display panel, are you reading 50amp? No offense, but have you inadvertently touched the 30/20amp button and selected less than 50amp? If so, while I realize you are reading loads <20, your starting amps as the compressors kick in are going to momentarily approach or exceed 30. Add to that, your normal load for TV's, refer, device chargers, etc., and the appliance load SarahW mentioned -- it all adds up.

Without a formal invite, we wouldn't presume to be some of SarahW's friends , but we replaced our Intellec circuitboard a couple of years ago. (in our 2007 Journey)

If you are NOT reading 50amps on your display panel, take a look at this thread, scrolling down to our post which includes part numbers and pictures. http://www.winnieowners.com/forums/f...ue-351526.html

Fair Winds and Following Seas

[goldymar]

The EMS is original, and there were no other loads than the AC, blower, and fridge. Last night I got the system to reset by turning the AC off at the thermostat. The EMS then brought all systems back online and I was able to turn the AC on with both compressors active.

Wayne, I am sorry but I don't know the answer to any of your questions.

I believe the system is only 30A, not 50A.

If the issue repeats itself today, I will attempt what worked yesterday. Maybe the EMS is load shedding as it should, but failing to reactivate the systems once the load drops.

[SarahW]

Originally Posted by Oldchinahand

Without a formal invite, we wouldn't presume to be some of SarahW's friends , but we replaced our Intellec circuitboard a couple of years ago. (in our 2007 Journey)

Hopefully we are all friends here, Oldchinahand! I wish I could be of more help to goldymar. Being hot is miserable.

[SarahW]

Originally Posted by goldymar

The EMS is original, and there were no other loads than the AC, blower, and fridge. Last night I got the system to reset by turning the AC off at the thermostat. The EMS then brought all systems back online and I was able to turn the AC on with both compressors active.

Wayne, I am sorry but I don't know the answer to any of your questions.

I believe the system is only 30A, not 50A.

If the issue repeats itself today, I will attempt what worked yesterday. Maybe the EMS is load shedding as it should, but failing to reactivate the systems once the load drops.

Goldymar--I'm not quite understanding about "2 compressors." Are you saying that you have two a/c units? If you do and it's a 30-AMP system then it will definitely shed the load when trying to run them both. (And as an aside, you should ascertain whether you have 30 or 50 AMP service; that is critical to know.)

I don't know if there is a method to test the Intellitec so hopefully someone more knowledgeable will chime in here.

[SarahW]

Goldymar--are you plugged into shore power or are you running the generator? I'm thinking that if you have "2 compressors" you have 2 a/c units and likely a 50 AMP coach. Does one of the a/cs continue to run?

Here is some info I found...

Here's a quote from Understanding Your RV's "SHOREPOWER" :

© "This system is designed to prevent ‘tripping’ the circuit breaker at the pedestal/post if the RV user inadvertently turns on too much electrical equipment – meaning the total amp draw will be greater than the rated level of the post’s circuit breaker.

The Intellitec 50 Amp Smart EMS™ recognizes when electrical power is being supplied to the RV. Through its diagnostic programming, it can determine if the incoming power is 50 Amp power, 30 Amp power, or Generator power. If the incoming power is from a 20 Amp source, the RV user must identify this lower power level by pressing the ‘30/20 Amp Select’ switch on the display panel. The system cannot discern the difference between 30 Amp and 20 Amp power!

When functioning at 30 Amp (or lower) power, the system controls the ‘On/Off’ operation for a maximum of six electrical loads. These loads are typically “heavy” loads (high amp draw) and their cumulative amp draw will trip the post’s breaker. Typical loads (in the order of lowest to highest priority) are the Electric Element in the Water Heater, the Rear Air Conditioner, possibly a Washer/ Dryer, and the Front Air Conditioner. (Other appliances may be attached to the system in larger RVs. However, the Microwave is controlled by the Inverter, if you have one.)

The system is also programmed with the ability to “memorize” the amp draw of each electrical load (appliance) attached to it. The system "memorizes" and stores the amp draw for each controlled load only when it is 'shed' (turned off by the system). It subtracts the new total amp draw of the RV from the original total amp draw - the difference is the amp draw of the shed load.

The system continuously monitors the total amp draw. If it gets too high, the lowest priority appliance will be shed (turned off). If the amp draw continues to be too high (or goes higher), the next lowest priority load(s) will be shed until the total amp draw is below the power limit of 30 or 20 Amps. This means that, no matter what order you turn appliances on, the Water Heater will always be shed first, then the Rear Air Conditioner, etc. The Front Air Conditioner is the last load to be shed. This is all done in the interest of protecting the RV from excessive amp draw.

When a load is shed, the appropriate ‘Power Status’ light on the display panel may blink for the first two minutes. This indicates a time delay to protect an air conditioner’s compressor. Once the time delay is completed, and there is enough power available to operate the load, the light will turn on and the appliance will be restarted. If there isn’t enough power available, the light will turn off and the appliance will remain off until adequate power is available.

When plugged into a lower level power supply or running the generator, the RV’s total amp draw is displayed in a two digit ‘Load Meter’ window on the display panel. It behooves each RV user to check the existing amp draw before turning on more equipment.

NOTE: The load shedding capability on a 50 Amp Smart EMS™ is automatically deactivated (turned off) if 50 Amp power is being supplied to the RV. Remember: Load shedding only occurs if a 50 Amp system is “dogged” (adapted) down to a lower power source (30 Amp or 20 Amp), or operating on Generator power. This means, when the RV is attached to a 50 Amp power source, the 50 Amp ‘Service Type’ light on the display panel will be lit, as will all of the ‘Power Status’ lights (all loads able to operate), however, the ‘Load Meter’ will be blank. Because the load shedding is deactivated, there is no need for the system to monitor the total amp draw and does not do so. So, my friends, when you are plugged into a 50 Amp power source, a blank ‘Load Meter’ does not mean the system is broken, but, instead, is working as designed!"

If you desire more technical detail, I recommend reading your Intellitec Manual very carefully. If you don't have one for your system, they are available at www.intellitec.com.

[Oldchinahand]

SarahW is on the mark. Highly recommend you go to http://www.intellitec.com/ and download the manual. You can also call them direct. They are very helpful. After unsuccessfully chasing a problem the last several days, that I was blaming on the EMS circuit board (replaced as previously noted) I called them this AM and they restored my confidence in the circuit board.

But first your issue. I took the liberty of pulling up your drawings and your original brochure https://winnebagoind.com/product-res...ct-information . Your Adventurer came std with a 5500W Onan @ 30amp. There was an option for a 7000W Onan @ 50amp. It appears that you do have a two stage compressor in your basement air. You should call Intellitec at 419-965-3014 and discuss your load shedding conundrum. BUT FIRST, look at your Onan and see which one you have, 5.5K or 7K, then look at your EMS display to see if you have a light for 50amp. Alongside the 20, 30, 50, Gen indicators will be a little screen that shows shedding order. As SarahW's excerpt describes, load shed is a 30 or 20amp function. Order of load shed is set at the factory, but the controlling dip switches on the (now infamous) circuit board can be reset at will (not likely smart). Armed with that information, when you speak to Intellitec, you should be able to ask pointed questions.

Since you asked about our latest go 'round with EMS, it goes like this. We pulled in, shut down the CUMMINS, made up the shore power, surgegard indicated green to go on all legs. But not one panel lit up on the One Stop. I blamed the EMS. Looked at trouble shooting in the manual, two choices. Laid my multimeter across J4 pin 4 (L1) and pin 6 (L2), read 240vac+/-. Good! Tested J3 pin 1 and pin 8 for 12vdc. Squat! Was sure another failed circuit board. Called Intellitec. Was informed that 12vdc does not come out of the circuit board, it comes in from 12vdc system and out to ONLY the EMC indicator panel. But, usually the rest of One Stop feeds from the same source. Guy tells me to look for a popped 12vdc breaker. The front TV breaker was popped. Reset it. One Stop lit up for a few seconds, then the breaker popped. Dark again. Guy tells me to look for a short in the entertainment area. Guy says only Winnebago knows why they fed the One Stop panel through the TV breaker. (And only W knows why they read the 3rd leg of 50amp off the water heater breaker) So, I pulled the TV out of the way, inspected that rat's nest of wiring , found a wire chafed by a sharp metal edge, cut and butt spliced it, set the breaker, all is well. Until our next electrical adventure.

We see you are just up the road in Gilbert. Used to live in Ocotillo Lakes. It's Hot! You should go to the mall and give the stink eye to all the rowdy teenagers until it cools off this evening.

Fair Winds and Following Seas

[jerichorick]

Originally Posted by goldymar

Hey all,

My 2000 Adventurer 32V must still be acclimating to its new life in the desert. The AC runs great until late afternoon, when the energy management system starts load shedding. With compressor#2 shut off, its gets pretty toasty. I don't really know what is happening, but my guess is something getting too hot. Does the EMS also do thermal management? The electrical loads are <20, so that's not the issue.

Help! Before my wife gets cooked!

Do you have the 50A option or standard 30A?


If the incoming power goes low a brown out condition will cause the EMS to shed loads to protect your system.


One problem I have experienced, more than once, is that of loose connections. I recommend opening the breaker at the pedestal and the generator (if Auto start system). Remove the cover from the Automatic Transfer Switch and the coach service panel. Tighten ALL of the screws that wires are under. Give a good look see at the wires. Inspect for charring or brittle wires from overheating. Repair as needed.


Looking forward to hearing what is causing your problems.
Rick

[les claassen]

Originally Posted by SarahW

Goldymar--I'm not quite understanding about "2 compressors." Are you saying that you have two a/c units? If you do and it's a 30-AMP system then it will definitely shed the load when trying to run them both. (And as an aside, you should ascertain whether you have 30 or 50 AMP service; that is critical to know.)

I don't know if there is a method to test the Intellitec so hopefully someone more knowledgeable will chime in here.

Are you hooked up to 50amp? Sounds like you’re on 30amp. The 30amp won’t support both compressors and will cut power to other power users as required. You have the basement AC unit, correct? Good Luck!

[kstateaddict]

After reading all of the posts I must admit it makes the Basement Air sound very complicated. We just returned from a 5000 mile trip and for the first time I fought the ac on most of the trip in our 2002 Winnebago Adventurer. Ours is a 32 v on a W20 chassis and has 50 amp service. Our problem started ( plugged in to 50amp) when it wasn’t cooling properly. After the system had been running for a couple hours. The number 1 compressor wasn’t working right and the number 2 compressor wasn’t coming on line. I have been aware for some time that no one wants to work on this system. Turning the ac breakers on and off I was able to get By. Using our generator really helped me identify the problem. The digital readout showed me exactly how many amps each compressor was using. With the ac in the “on” position instead of “auto “ #1 compressor was only pulling 3amps. The bottom line is the compressor was weak causing all kinds of issues. We just installed a brand new unit and can’t wait to take our coach out. Hope that I haven’t confused everyone.

[jerichorick]

Originally Posted by kstateaddict

After reading all of the posts I must admit it makes the Basement Air sound very complicated. We just returned from a 5000 mile trip and for the first time I fought the ac on most of the trip in our 2002 Winnebago Adventurer. Ours is a 32 v on a W20 chassis and has 50 amp service. Our problem started ( plugged in to 50amp) when it wasn’t cooling properly. After the system had been running for a couple hours. The number 1 compressor wasn’t working right and the number 2 compressor wasn’t coming on line. I have been aware for some time that no one wants to work on this system. Turning the ac breakers on and off I was able to get By. Using our generator really helped me identify the problem. The digital readout showed me exactly how many amps each compressor was using. With the ac in the “on” position instead of “auto “ #1 compressor was only pulling 3amps. The bottom line is the compressor was weak causing all kinds of issues. We just installed a brand new unit and can’t wait to take our coach out. Hope that I haven’t confused everyone.

Start capacitors are a common failure point. Too bad you didn't try that first. They are not expensive and readily available. The 3amps you saw was just the fan running. The compressor was not.



Let us know how your new unit works. Hope you are able to stay cool.

[SarahW]

Originally Posted by kstateaddict

After reading all of the posts I must admit it makes the Basement Air sound very complicated. We just returned from a 5000 mile trip and for the first time I fought the ac on most of the trip in our 2002 Winnebago Adventurer. Ours is a 32 v on a W20 chassis and has 50 amp service. Our problem started ( plugged in to 50amp) when it wasn’t cooling properly. After the system had been running for a couple hours. The number 1 compressor wasn’t working right and the number 2 compressor wasn’t coming on line. I have been aware for some time that no one wants to work on this system. Turning the ac breakers on and off I was able to get By. Using our generator really helped me identify the problem. The digital readout showed me exactly how many amps each compressor was using. With the ac in the “on” position instead of “auto “ #1 compressor was only pulling 3amps. The bottom line is the compressor was weak causing all kinds of issues. We just installed a brand new unit and can’t wait to take our coach out. Hope that I haven’t confused everyone.

Interesting. I'm not familiar with the basement a/c at all so I should have stayed out of this discussion!! I had no idea the system has 2 compressors. My simple mind went directly to roof a/c.

[al1florida]

Originally Posted by les claassen

Are you hooked up to 50amp? Sounds like you’re on 30amp. The 30amp won’t support both compressors and will cut power to other power users as required. You have the basement AC unit, correct? Good Luck!

There is no reason why 30A service won't run both compressors. The total amps pulled by both compressors running is about 20-24amps. Also the standard electric service for the 2000 Adventurer is 30 amp service and a basement A/C.


Now if some other load comes on, such as the electric side of the water heater, that is a different issue.

[al1florida]

Originally Posted by goldymar

Hey all,

My 2000 Adventurer 32V must still be acclimating to its new life in the desert. The AC runs great until late afternoon, when the energy management system starts load shedding. With compressor#2 shut off, its gets pretty toasty. I don't really know what is happening, but my guess is something getting too hot. Does the EMS also do thermal management? The electrical loads are <20, so that's not the issue.

Help! Before my wife gets cooked!

Goldymar,
I hope by now the problem has been resolved. It has been 7 days since you first posted the problem.
The posts in this topic have bounced all over the place. The info about the EMS seems very good, but very, very technical, and may not be what you need right now.
jerichorick had a very good thought: "If the incoming power goes low a brown out condition will cause the EMS to shed loads to protect your system."
It is not unusual in an RV Park in very hot weather and all the RV's running their air conditioners to the max to have low voltage on the shore power. If there is a way for you to display the 120V shore power with your EMS, watch the voltage to see if it is dropping below 110V. If this is the problem, the EMS probably won't shed power until the voltage gets down to near 100V.

Is there any chance you water heater is set to electric instead of gas? The water heater kicking on would cause the EMS to shed power.

Loose connections as jerichorick suggested is a possibility, but it means tearing into electrical components.

Hope this helps.

[creativepart]

It's definitely the 30A service that's the issue.

To run both AC units you need more than 30 amp service. I run my RV on 30 when I have the RV at home because I don't have a 50 receptacle set up in my garage for the RV. The EMS service does a GREAT job of managing the power and sometimes it will run both of my AC units - but as the load on the ACs increases it runs them separately allocating power to the compressors when it can and shedding one of them when it can't.

I've noticed that in the morning it efficiently runs both AC units, but later in the heat of the day it starts picking and choosing which one to run when.

When we go camping in the heat of the summer we'll never go to a place without 50 amp service. Just for this very reason.

There are 50 amp adapter cords that have one 30 amp input and one 15 amp input to combine to provide 45 amps to your system. Which sounds like a simple solution to your problem BUT!! it's probably not. All RV Park pedestals have ground fault 15/20 amp plugs and if you try to use such a combiner/adapter it will simply trip the 15 amp ground fault. If you can get 15 amps of power from somewhere else, not on a ground fault protector, it would work with such an adapter to provide 45 amps.

[al1florida]

Originally Posted by creativepart

It's definitely the 30A service that's the issue.

To run both AC units you need more than 30 amp service. I run my RV on 30 when I have the RV at home because I don't have a 50 receptacle set up in my garage for the RV. The EMS service does a GREAT job of managing the power and sometimes it will run both of my AC units - but as the load on the ACs increases it runs them separately allocating power to the compressors when it can and shedding one of them when it can't.

I've noticed that in the morning it efficiently runs both AC units, but later in the heat of the day it starts picking and choosing which one to run when.

When we go camping in the heat of the summer we'll never go to a place without 50 amp service. Just for this very reason.

There are 50 amp adapter cords that have one 30 amp input and one 15 amp input to combine to provide 45 amps to your system. Which sounds like a simple solution to your problem BUT!! it's probably not. All RV Park pedestals have ground fault 15/20 amp plugs and if you try to use such a combiner/adapter it will simply trip the 15 amp ground fault. If you can get 15 amps of power from somewhere else, not on a ground fault protector, it would work with such an adapter to provide 45 amps.

The only way the should be shedding power is if the total amps are approaching 30amps when on 30amp service.

I flat don't understand why, if the only thing running is the A/C and it is only pulling 22-24amps why in the world would the EMS turn off the 2nd compressor?

If the EMS is shedding power at 24amps I would consider that a failure of the EMS.

It is very simple to me, EMS should not shed power at 24amps on a 30amp service.
Now if there are other things pulling power, that is a different issue.

I sure would be watching the AC amps on my EMS to see if the amps are indeed going up to near 30amps and then figure out what I need to turn off.

[al1florida]

Back to the original poster:
Goldymar,
Try turning your fridge to gas only. The electric operation of the fridge pulls a few amps that may be just enough to trigger the EMS to shed power.
Also when you wrote that the EMS is showing you are pulling <20amps. Were you able to get that reading within a few minutes of the EMS shedding power, or was that after the 2nd compressor turned off?

[creativepart]

The EMS is not going to allow you to pull exactly 30 amps on 30 amp service. It will reserve power for battery charging, lights, fans, water pump (if needed), etc.

When we first got ours I thought the same as you but learned the EMS was smarter than I was and now I feel it is a smart piece of gear that I’m happy to let it do it’s job.

Also the system will show you the amps that were used previously on various loads. Look at one of your AC units on the list of loads I bet you’ll see at least one AC has pulled 18 Amps recently. So on 30 amp service it’s not going to let two loads that occasionally pull 18 amps run at the same time. It’s smarter than that.