AC's were working now cant get them to run

[JimC295]

I've searched this forum and cannot find an answer to my issue so here goes. This is my 1st MH and so am not familar to the systems and the indications I explain may not be related to each other. I drove the coach home and because the dash AC was not working well I ran the generator and ran the roof AC's No Issues. After I got home I tried to run on a 20amp circuit thing the power management system would make this happen, it did not. The power blinked a few times and then tripped the breaker in the house. After that happened I fired up the generator to get them runing again and no joy I messed with the thermostat to try to get the front AC running only and still no luck. At this point I'm thinking Ive screwed up the Tstat programing so broke out the book. Ive got the thermostat set to Auto fan, cooling and zone 1 with zone 2 blinking but it will not start. I noticed when the previous owner cycled the AC's the power management display would light up and show the amps the AC was drawing but now that display is not working on generator. If I plug in to the shore power 20am circuit it will work?? I have power to the Tstat so can this group point me in a direction to where I need to look? I know I screwed up by not reading the operating instructions 1st so please don't beat me up over that. Ive had experience working on AC systems many years ago in the military so I still remember the basic operation. I'm thinking this is related to the power. but am not sure where to start. I have found the breaker panel and the breakers aren't tripped. Thank you in advance for your help.  

[klcdenver]

Check your breakers on the generator. They are by the start switch on the generator itself. Stop using 20 amp shore power from your house, that will not run your AC because of the invertor/charger also drawing power. It takes about 20 amps or more just to start a roof mounted AC and about 13-17 amps continuous amps to run. 

[jacwjames]

Are you seeing the EMS (energy management system) display light up?? 

If you are plugged into to a 20 amp circuit and trying to run an AC you won't be able to run anything else.  Is the water heater off?  Are your house batteries trying to charge at a higher rate off the inverter?? 

 

[Tom Cherry]

7 hours ago, JimC295 said:

I've searched this forum and cannot find an answer to my issue so here goes. This is my 1st MH and so am not familar to the systems and the indications I explain may not be related to each other. I drove the coach home and because the dash AC was not working well I ran the generator and ran the roof AC's No Issues. After I got home I tried to run on a 20amp circuit thing the power management system would make this happen, it did not. The power blinked a few times and then tripped the breaker in the house. After that happened I fired up the generator to get them runing again and no joy I messed with the thermostat to try to get the front AC running only and still no luck. At this point I'm thinking Ive screwed up the Tstat programing so broke out the book. Ive got the thermostat set to Auto fan, cooling and zone 1 with zone 2 blinking but it will not start. I noticed when the previous owner cycled the AC's the power management display would light up and show the amps the AC was drawing but now that display is not working on generator. If I plug in to the shore power 20am circuit it will work?? I have power to the Tstat so can this group point me in a direction to where I need to look? I know I screwed up by not reading the operating instructions 1st so please don't beat me up over that. Ive had experience working on AC systems many years ago in the military so I still remember the basic operation. I'm thinking this is related to the power. but am not sure where to start. I have found the breaker panel and the breakers aren't tripped. Thank you in advance for your help.  

Back to basics.  As well as questions….and also a simplistic explanation. Assume you have the 5 button Thermostat.  Don’t know if you have two or a single.  Doesnt matter.

Don’t know if you took off the thermostat or unplugged it….so here are the basics….

The problem is simple.  You should not attempt to use 20 amps and try to run an AC.  There are ways…but we don’t recommend trying until folks have the basics…. Each AC unit has an internal 20 Amp breaker and the Inverter (charging circuit) and a single AC will overload the EMS or what you described as the power management device. The Inverter will be using high current trying to charge the batteries.  Then the EMS will shed on and off an AC and that frequent cycling will damage the shedding relays on the Intellitec.

SO….here is the way to get it going.  First.  Reset the Thermostat.  Do NOT need shore as this is DC…so batteries must be OK….turn off the bottom switch.  Hold ON the Mode and Zone buttons…turn on power.  FF will show up.  Now, we recommend not using the bottom switch.  You can’t buy a nee thermostat only used or refurbished .  Use the Zone button snd selcect the front..Zone 1.  Use the MODE to off.  Leave the thermostat power on and only off when you need to reset.  Do the same for the rear or zone 2.  If you have a separate rear…reset and then set Mode to OFF.

Start the Generator.  Always let the run for a few minutes…minimum 2…usually 5.  NEVER EVER start the generator with the AC’s set to anything bur OFF in the MODE setting.  OK…after 5 minutes….set the Mode to AC…it will take approximately 2 minutes before the thermostat “approves” giving the AC the 120 VAC power….let it run.  Repeat for the back.  

You should be good to go.

TWO MORE MUST KNOWS.  I can’t get an online sales brochure or your manual….so this is somewhat generic as I don’t know your brand of Inverter.

If you use 20 amp service, you have to “set” or tell the inverter, or at least on a Magnum, that you are on limited power.  Read or download the manual for your inverter .  Magnum has a SHORE button.  Push it.  Set to  30A all the time.  That is based on the INTERNAL 30A main panel inverter circuit breaker….NOT THE SHORE.  If you are on 20, set it back to 20.  Then reset to 30 all other times.

If you are on a 20 A line cord…there is a button on the Power EMS remote.  Push it to display 20 A.  It defults to 30.  That is one of the reasons that it might have been in a funk….but I suspect the EMS was reacting….  I can’t fully explain why the Generator seemed to act funny, but I made the mistake of switching off the 50 A with both AC’s on and the Generator had only been running a minute or so and it caused a fault and I thought it was a big time mistake.  I drove with the front HVAC on and waited maybe 30 minutes.  Roof AC’s all off. Restsrted the generator.  Let if run for maybe 15 minutes….that knocked down the bulk charging load….started one roof unit……let it run for 10 minutes….then the other. Generator was OK and never has had any issues.  So, it happens…to folks like me that should know better 

Final recommendation.  Dedicate 3 or 4 hours and start with chapter 1 and slowly read and comprehend the manual.  Don’t binge…do one chapter at a time…then stop…next day…another.  What I posted here is all in there,,except the reset for the thermostat.  Pay PARTICULAR attention to the bold warnings and heed them.  For example…a frequent issue is AC cycling.  In high temperature and  high humidity, you MUST put the fan on auto or HIGH.  But some don’t like the noise or the cycling on at night.  If you don’t follow that operation precaution, they will cycle on and off snd not cool and  that is not good for them.  

Thats it.. Welcome aboard…

 

 

[cbr046]

I'm guessing you have a Xantrex inverter.  Our 2003 Endeavor does . . . .

Every time I plug into shore power the Xantrex inverter goes through a battery recharge cycle.  It doesn't matter if the batteries are fully charged or not, plugging into shore power puts 10-13A of 120V into the batteries, then it drops down to 6-8A then, eventually, it stops (over)charging. 

I'd like to bypass this recharge cycle mode but have yet to research it.

As Tom said, you need to run the generator several minutes before it even switches on the AC.  Yes, the generator chugs along several minutes then later you get 120VAC.

Same thing for the roof AC's.  They need to run several minutes before they engage the compressor.  So now you have 2 delays, 120V AC and HVAC compressor.

Patience is a virtue (I don't have it either).

Once the compressor kicks in you'll have a 3rd delay waiting for the evaporator coil to start giving cool (or warm in heat pump mode) air coming from the registers.  I suggest a thermometer attached to the return air intake, take a measurement, then move it to the output register.  Eventually you'll see the temp start coming down.  Once it stabilizes record that temp.  You should see a 20F differential in the two temps.  I just checked mine yesterday (original 2003 AC's) and my rear AC was getting ~17F differential while the front was at 20F. 

Each AC unit will draw 21-23A at 120V.  I installed SoftStart's on both units so I could run them one at a time on a 20A circuit.  It worked, but it melted the 15A adapter plug 😮 . 

After your test shut down the AC unit(s).  I'll run fan mode for a few minutes to dry out the evaporator coil (old habit, not sure it really does anything) then I'll shut the entire unit down, wait a few minutes more to let the generator cool down, per the manual! then shut the genny off. 

And yes, reading the manual is a good thing.  Re-reading is even better!

Good luck,

- bob

 

Edited September 14, 2023 by cbr046

[JimC295]

Thanks to all, I now have a start point to unscrew what I messed up.

3 hours ago, jacwjames said:

Are you seeing the EMS (energy management system) display light up?? 

If you are plugged into to a 20 amp circuit and trying to run an AC you won't be able to run anything else.  Is the water heater off?  Are your house batteries trying to charge at a higher rate off the inverter?? 

 

My EMS display only lights up when on my shore power. I have everything off and after a bit I try to start the AC. I did not know about the extra inverter start up amperage so gonna try to reset the systems per Toms suggestions and try again on generator.

[JimC295]

6 hours ago, klcdenver said:

Check your breakers on the generator. They are by the start switch on the generator itself. Stop using 20 amp shore power from your house, that will not run your AC because of the invertor/charger also drawing power. It takes about 20 amps or more just to start a roof mounted AC and about 13-17 amps continuous amps to run. 

This was the solution to not seeing the intellitec light up. Then the info provided by Tom on resetting my thermostat got my AC's running again. You guys are awesome I was really upset about this issue because I did the typical guy thing and did not read the Thermostat instructions before I started pushing buttons. I'm all good now!

Edited September 14, 2023 by JimC295

[cbr046]

2 minutes ago, JimC295 said:

This was the solution to not seeing the intellitec light up. Then the info provided by Tom got my AC's running again. You guys are awesome I was really upset about this issue because I did the typical guy thing and did not read the Thermostat instructions before I started pushing buttons. I'm all good now!

THAT'S GREAT!  But I already had the below all typed up!  It still might be a good guide . . . . .

 

51 minutes ago, JimC295 said:

My EMS display only lights up when on my shore power. I have everything off and after a bit I try to start the AC. I did not know about the extra inverter start up amperage so gonna try to reset the systems per Toms suggestions and try again on generator.

On generator everything should work, except the amps display on EMS (normal).  Just don't forget all the built in delays. 

On 50A shore power everything should work. 

On 30A shore power one AC should work. 

On 20A shore power one AC *might* work, or microwave.  You have to pick one or the other. 

On 15A shore power you can run the refrigerator and charge batteries.

If your EMS is set (shore power 30A,20A,15A) the EMS will automatically shut off different devices (AC, water heater, washer/dryer?) 

If your EMS is set on 15A maybe the AC will never start?  I'm not sure . . . .

If you have a long extension cord your voltage will drop when switching on a major load (AC, microwave, elec water heater, space heater, etc)

- bob

[JimC295]

7 minutes ago, cbr046 said:

THAT'S GREAT!  But I already had the below all typed up!  It still might be a good guide . . . . .

 

On generator everything should work, except the amps display on EMS (normal).  Just don't forget all the built in delays. 

On 50A shore power everything should work. 

On 30A shore power one AC should work. 

On 20A shore power one AC *might* work, or microwave.  You have to pick one or the other. 

On 15A shore power you can run the refrigerator and charge batteries.

If your EMS is set (shore power 30A,20A,15A) the EMS will automatically shut off different devices (AC, water heater, washer/dryer?) 

If your EMS is set on 15A maybe the AC will never start?  I'm not sure . . . .

If you have a long extension cord your voltage will drop when switching on a major load (AC, microwave, elec water heater, space heater, etc)

- bob

Bob, thanks, I only tried to run the AC on my 20amp circuit because I was able to run my 15K rooftop unit in my 5th wheel. I was unaware the inverter would also kick on which is what make everything overload and trip the breaker. So I guess one of those soft start high dollar units is needed but for now only on Generator.   I learned the value of a forum to access shared knowledge years ago and so I will be more careful in the future as I go about learning about this coach. Again thanks all for your help

 

[Tom Cherry]

1 hour ago, JimC295 said:

Bob, thanks, I only tried to run the AC on my 20amp circuit because I was able to run my 15K rooftop unit in my 5th wheel. I was unaware the inverter would also kick on which is what make everything overload and trip the breaker. So I guess one of those soft start high dollar units is needed but for now only on Generator.   I learned the value of a forum to access shared knowledge years ago and so I will be more careful in the future as I go about learning about this coach. Again thanks all for your help

 

FWIW…and a bit of explanation and followup.  FIRST…glad it worked out.  I know I was in a panic.  My mistake was wanting to be able to switch immediately to Generator.   So, when you turn on the thermostat or the thermostat and it calls for AC (or heat pump), there is an automatic 120 second delay.  We usually do this but the AC or thermostat had not been shut down.  So, genny was running….  NOW, back then, I was not as knowledgeable about how the ATS’s work.  This is generic, but most do, or the more common ones.  You can run both Shore and Generator.  But, when the ATS “senses” or measures the voltage between Line 1 or Line 2 and Neutral, that is the FLAG.  Generator is ON.  Switch to Generator power.  The ATS is usually always default on SHORE…some upper ends might be more sophisticated….but knowing the usual way it works is sometimes not understood.

However….anytime we have a new owner, may or may not have any RV experience, we always post a warning.  Check your ATS.  If it is an IOTA 50R, it is a fire and safety hazard and should be replaced, the quicker the better.  There have been fires and damage…. After Monaco went into Bankruptcy, Navistar bought them out.  Monaco, and a lot of other RV manufacturer’s had installed the IOTA.  Once the defect was known, IOTA refused to accept the NHTSA recall.  Most manufacturers did a voluntary recall and paid for the replacement.  Your MH, like mine, was NOT covered in Navistar’s recall….they had NO liability.  They did recall all they put in.  The ESCO LPT50BRD is the most commonly stocked unit.  Monaco had a long term relationship with ESCO.  That is why it recommended as the quality and tech support it great.  Many members have chosen other brands…what is important…if your rig was not upgraded, that should be a top priority.  We have many threads here on exactly how to do that. Probably 80% of our members DIY…

If you have a Freedom or a Heart or Xantrex, we have most of the owners manuals in our files.  Use any of those 3 key words and select files (drop down when you click on EVERYWHERE in the upper right search box…you can download…. So, you may not have to reset the “shore” like the Magnum’s.  But since it is the prevalent brand say mid 2000’s on….we discuss that.  If, BTW, you ever have an inverter issue, please specify the brand as myself and others sometimes don’t know what you have and our brains focus on Magnum…but I did qualify that earlier and said…”typical”.

[Ivan K]

Jim, if you have Xantrex inverter, you can adjust the incoming power rating and percentage of it to be used for charging to its minimum. I routinely run one AC unit on 20A when parked at the shop. One time I accidentally had engine preheat ON and kept throwing the breaker. I never use it so it was the last thing I suspected.

[Tom Cherry]

1 hour ago, JimC295 said:

Bob, thanks, I only tried to run the AC on my 20amp circuit because I was able to run my 15K rooftop unit in my 5th wheel. I was unaware the inverter would also kick on which is what make everything overload and trip the breaker. So I guess one of those soft start high dollar units is needed but for now only on Generator.   I learned the value of a forum to access shared knowledge years ago and so I will be more careful in the future as I go about learning about this coach. Again thanks all for your help

 

Great summary….I forgot to say one thing….when the EMS reads Line 1 & Line 2 and gets 240 or so volts….it says….all is well. 50A service and actually goes to sleep.

BUT if you only have 30 Amp, then that is typically, one line so when the EMS checks L1 to L2….zero volts.  Then it defaults to 30.  

The other thing….if you see current displayed….that is the current tap toroidal  coil which reads only the neutral.  If you understand in and out of phase Line 1 & Line 2 (or google it), with a 240 V which is, BTW, how a 50 A pedestal is set up…we do NOT use 240 vac devices….then the neutral on an Out of Phase or 240 VAC 50 A will read the algebraic sum of the neutrals.  Line 1 is say 30 and line 2 is say 15.  The algebraic sum is 15..  BUT if that is an INPHASE circuit….then there is NO voltage berween Line 1 & line 2.  So the EMS would add….or show 45.

You may understand or not be familiar….but this is the takeaway.  Your Generator is a 120 VAC….in phase.  You have a dual pole 35 (maybe 30?) breaker.  Two separate LINES.  1 & 2.  But if there is 17 amps on L1 and 17 amps on L2….the EMS will read 34.  So, in theory….you have the capacity for 35 & 35…or 70 on the neutral.  However, the #6 stranded SINGLE or common neutral line is only rated for 55-58 AMPS…anytime you push the EMS current to above 50, beware.  We have had folks that had issues…. Yes, it was built that way…Monaco often didn’t bother to read….that is why sometimes there are relay failures on the shedding relays in the EMS and frequent or on and off shedding…kills the contacts.

For our rigs…the rule of thumb….only run one AC on a 30 amp circuit….it can be done it you can shut off the charging side of the inverter and do some other things….but if you need 2 AC and have only a 30 amp hookup…better to use your genny until you can exist on one AC…then go to 30 A  shore.

 

[JimC295]

1 hour ago, Ivan K said:

Jim, if you have Xantrex inverter, you can adjust the incoming power rating and percentage of it to be used for charging to its minimum. I routinely run one AC unit on 20A when parked at the shop. One time I accidentally had engine preheat ON and kept throwing the breaker. I never use it so it was the last thing I suspected.

Ivan, I do have the Xantrex.  I also think I have an owners manual on it so I'll read up on this subj.