Amp Draw from AC's

[Venturer]

We just drove from WI to our home in AZ. 2000 miles in 4 1/2 days. Everything was fine till the 4th day. The new engine driven AC compressor failed, so  we were running all three roof AC's. They abruptly quit running and found that the 50 amp breaker had tripped. I reset it and continued. It tripped a second time, so I ran just two of them. On the last short day, the generator would not start either AC units. It would only produce 115-116 volts. Today, plugged into our 50 amp shore power, the front AC runs at 118 volts pulling 14 amps. The middle one is drawing 17 amps @ 117 volts and the rear is pulling 17 amps @ 117 volts. They work as designed. I shut them off, turned off the shore power and started the 12.5 KW generator. The voltage was 118 volts on both legs with no load. After starting the AC's The voltage went up to 120 volts. The front AC drew 16 amps @ 121 volts.The middle AC pulled 17-19 amps @120 volts. The rear pulled 21 amps @120 volts. When I ran both the middle and rear AC together, they pulled 40-44 amps @ 118 volts. At one instance, the amps went to 47 amps. I'm at a loss as to what the problem is when the generator can provide better voltage than the shore power, but draws 30% more amperage. I'm thinking  the transfer switch could be creating resistance, but I'm no electrician. I'm taking the coach back to the shop that installed the engine AC compressor for warranty work. I would like them to address the generator problem, not sure how informed they might be. Any suggestion from the more informed members here will be appreciated. Thanks       

[Tom Cherry]

1 hour ago, Venturer said:

We just drove from WI to our home in AZ. 2000 miles in 4 1/2 days. Everything was fine till the 4th day. The new engine driven AC compressor failed, so  we were running all three roof AC's. They abruptly quit running and found that the 50 amp breaker had tripped. I reset it and continued. It tripped a second time, so I ran just two of them. On the last short day, the generator would not start either AC units. It would only produce 115-116 volts. Today, plugged into our 50 amp shore power, the front AC runs at 118 volts pulling 14 amps. The middle one is drawing 17 amps @ 117 volts and the rear is pulling 17 amps @ 117 volts. They work as designed. I shut them off, turned off the shore power and started the 12.5 KW generator. The voltage was 118 volts on both legs with no load. After starting the AC's The voltage went up to 120 volts. The front AC drew 16 amps @ 121 volts.The middle AC pulled 17-19 amps @120 volts. The rear pulled 21 amps @120 volts. When I ran both the middle and rear AC together, they pulled 40-44 amps @ 118 volts. At one instance, the amps went to 47 amps. I'm at a loss as to what the problem is when the generator can provide better voltage than the shore power, but draws 30% more amperage. I'm thinking  the transfer switch could be creating resistance, but I'm no electrician. I'm taking the coach back to the shop that installed the engine AC compressor for warranty work. I would like them to address the generator problem, not sure how informed they might be. Any suggestion from the more informed members here will be appreciated. Thanks       

MANY ANSWERS TO YOUR QUESTIONS...

FIRST... ASSUMING you are a bit of a DIY (not an electrician).  The Front HVAC is an AUTOMOTIVE one.  No SELF RESPECTING GOOD Car or Truck Shop has a CLUE.  The systems are unique.....so I would NOT waste my time...and a LOT of money for someone to work on something that they have NO IDEA of how it works.

HERE MAY BE THE DEAL.

WITH POWER OFF....Genny CB Tripped...as IN OFF.  Cover the SOLAR or disconnect the charging wires to the battery.

Remove the cover from the MAIN PANEL.  Watch a YOUTUBE video on POPPING out or removing a Circuit Breaker.  The 120 VAC breakers are a SNAP IN.  You lift ONE side...the WIRE side....sort of lift it up a 1/4" or so then PUSH and reseat it.  You may see ONE or more of the CB's DROOPING as hanging lower.  That is causing a High Resistance Connection....  THEN use a good sized screwdriver....tighten EVER SCREW in the PANEL  Do the BLACKS on the breakers....the WHITES on the Neutral and the GROUND (Bare).  That is NEEDED and takes no CIRCUIT SKILL.

NEXT...  From what you said.....your compressors are OLD>  They should run around 13 - 16 Amp....while running.  BUT, when they start up....there is an INDUCTIVE (look it up and GOOGLE) AMP SURGE.  There is a Capacitor in every unit.  They OFTEN GO BAD.  The LOGICAL method.  DO THE PM.  Then only TURN ON....ONE....and let it RUN....then bring on another....  and THEN the final one.  FWIW, It is CHEAPER to run the GENNY and Use the ROOFTOP units than to RUN the FRONT HVAC.  You pay more in decreased MPG of the ENGINE....than the small amount of fuel for the GENNY.  Many have tested and calculated...as I did...

OK....If you are seeing a HIGH running AMPS.....then you have to assume the compressor is WARING OUT...as in it has MORE FRICTION.

BUT, if you are using your Aladdin...you need to TURN OFF the INVERTER or the CHARGER.  You can NOT accurately state what the AMPS IS...as the Charger may be kicking in.....so CHARGER OFF.  NO OTHER AC devices plugged in....or RUNNING. NO TV's or such.

THEN....WITH only ONE AC ON... TURN OFF THE OTHER TWO to OFF.  Start up the ONE HVAC.  If you see a surge of say 20 AMPS....and then it settles down....if it is below 17, that is OK.  BUT, if it runs above 17...The COMPRESSOR is failing or is worn out....and needs replacing.  IF you see a really big, quick surge...say above 20 Amps....Purchase a NEW Capacitor and PUT it in.  That will sometimes help. Folks DO use a $350-$400 SOFT START (two Brands....same concept).  BUT, if you buy THREE of them....that $1000 - $1200 would be GONE.  Eventually, a failing or partially worn out Compressor is gonna need replacement.   SO, if you mistakenly THINK that the SOFT START will prevent the reoccurrence on the NEW UNITS.  NOPE... it is for Compressors that are worn and have too much internal friction.  They take a LARGER and LONGER surge of current to start....and then they pull MORE....

That's the deal....stuff you can do.  Changing a Capacitor is simple.  You can SEARCH here and find the VALUES or read the label on yours...

Good Luck....

[Venturer]

Thanks Tom. I did not turn off the charger and inverter, so I retried the test with them both off and got the same results. Probably because everything was fully charged and all other electrical was off. When on shore power, all three units seem to be working fine. 13-14 amps on the front and 17 amps each on the middle and rear units. From that assume all three are working as designed. The puzzling thing is that the generator carried a slightly higher voltage but a higher amp draw on all of the units, especially the middle and rear. The problem has to be where the generator feeds into the electrical system. Transfer Switch ????. The shop I am taking it to is an RV repair facility and they only work on RV's, mostly motorhomes, so they will certainly know more than me. I was hoping to offer some educated suggestions.   

[Tom Cherry]

22 hours ago, Venturer said:

Thanks Tom. I did not turn off the charger and inverter, so I retried the test with them both off and got the same results. Probably because everything was fully charged and all other electrical was off. When on shore power, all three units seem to be working fine. 13-14 amps on the front and 17 amps each on the middle and rear units. From that assume all three are working as designed. The puzzling thing is that the generator carried a slightly higher voltage but a higher amp draw on all of the units, especially the middle and rear. The problem has to be where the generator feeds into the electrical system. Transfer Switch ????. The shop I am taking it to is an RV repair facility and they only work on RV's, mostly motorhomes, so they will certainly know more than me. I was hoping to offer some educated suggestions.   

YOUR CALL.

BUT, you do need to be aware.  You have an OUT OF PRODUCTION SurgeGuard ATS.  It has a SPECIAL output module.  That module feeds the INFO into the Aladdin system.  Most folks do everything they can to keep it working.  We have had several writeups about HOW to install a NEW ATS and then salvage the Module.

Not exactly for the FAINT HEARTED.  But these folks did it.  

To explain.  Surge Guard, when your ATS was made....was producing the ATS (SAME PN...that is WHAT IS REALLY CONFUSING).  Then later on... Aladdin quit or went out of business.  ANYWAY.  The 2005 (or maybe a little earlier) Upper ENDS....like your Sig....have a Combo SURGE Suppressor and ATS Combo.  The SURGE is achieved by some little "NECCO WAFER" looking electronic component on a Printed Circuit Board.  That switch, since a LOT of MH's had the Aladdin, had a special "INTERNAL MODULE".  It sends out a coded signal to the Aladdin.  OK....the MH industry got decimated circa 2008 and Monaco went bankrupt (as did many other ones) and THEN SurgeGuard put out a NEWER model of the Combo Surge and ATS switch.  BUT, there was NO MARKET nor demand for the Aladdin OUTPUT.  They DROPPED IT OUT.  YES....not VERY "Customer" friendly.  Sell a REPALCEMENT that has the SAME PN and same SPECS.  BUT, the internals are different.  There is NO OUPTUT Terminal or place to PLUG IN THE ALADDIN interface.  SO, we have folks all the time say..

Put in a NEW SurgeGuard (SAME PN) ATS.  NOW, my Aladdin DON'T WORK.  What did I (or the TECH) do WRONG??? I WANT IT FIXED.  

The ANSWER IS...  You (or the TECH) did NOTHING WRONG.  The NEW SurgeGuard Surge and ATS device DOES NOT SUPPORT or WORK WITH THE Aladdin system on your MH.  OMG or @$#$@# is the usual response.   I NEVER KNEW...

You may have 100% confidence in your EXPERTS.  BUT, only 10% of the TECHS (my GUESS....as we have folks post things like... MY TECH DID NOT KNOW....YOU JUST SOLVED IT) are NOT that familiar or knowledgeable about the Monaco's.  EVEN REV doesn't know.

SO...  Before I authorized a MIGHT NOT KNOW Tech to diagnose and tell you he can FIX your issue....I would be VERY Surprised.

The ISSUE is either in your MAIN panel and the PM needs to be DONE THERE....  That is the FIRST STEP.

The readings that you have on the Aladdin might be OK.  It just depends on when you take them.

I hope you understood the point that "YOU MIGHT be able to spend $1,200 or so.....and get a year...or more....how BAD is your Compressor worn?" That is more rehetorical and NOT anything that anyone can answer.  SO...  You need to be aware that making sure that the connections for the AC in the Plenum are TIGHT.  You need to make sure the Main Panel does not have LOOSE wires.  You need to make sure that the Circuit Breakers are OK.  THEY DO GO BAD...  You need to make sure that the Connections in the ATS are TIGHT.  That's about the list.

BUT IF YOU SAY.  I think I got a bad ATS....sometimes that will "influence" the tech.  And it never fixes it.

It is BETTER that you learn what the issues can be.  Odds are....if you have a lot of use on the AC units....it is getting time....to either replace them....or spend the $$ for new one.  Be aware that if you only REPLACE ONE....There will be at least $400 EXTRA to pull the NEW controller and install a DUMB DOWN controller.....otherwise it will NOT work with your 5 Button thermostat.  You also need to be aware that there is a scarcity of 5 Button Thermostats and you might have to chase around.  Ebay supposedly had them.

SO...  From MY POINT of VIEW.  If I had a HVAC go bad. I would not sink lost money in the SOFT STARTS.  YES>..that might buy you some time.  If you are going to sell it....that might be a good deal. BUT, if you plan to keep it...  DO you WANT to spend $400 or so to DUMB DOWN the unit.  Once you have to REPLACE the OTHER TWO and get the NEW Thermostat (CCC2...the Old system is a CCC), you have to have the Original controller installed in the FIRST unit. It is NOT cost effective to keep DUMBING DOWN Units.

Just trying to make you aware and also temper your expectations....unless you have a really GOOD shop.  

Good Luck....You might want to review my posts again and let it sink it.  

Let us know what the tech finds.....it MAY BE SIMPLE.  But folks have left units for days and ran up a BIG Troubleshooting bill or authorized repairs that really were NOT the issue...

[Venturer]

Thanks Tom for the information. It's a lot to digest. Might have to read it a few times. As I said before, all three AC units work fine when plugged into shore power. 14 amp draw on the front and 17 amps on the middle and rear units. That leads me to assume they are working as designed. The higher amp draw when on the generator leads me to think resistance in the connections of that circuit. The Generator has less than 1000 hours on it. Everything was fine, or at least it seems so, until the last couple days ago. The shop that is working on the chassis AC told me they referred all house AC work to another shop in town.  I should get the coach back tomorrow and will try to check for loose connections before taking it to the other shop. It would be helpful if I could locate a service tech in the Lake Havasu City, AZ area who is familiar with Monaco's design before relying on an unexperienced one. Thanks for your input.    

[Venturer]

Just got the coach back with the dash AC repaired and working fine. I removed the cover of the Magnum inverter/charger and tested for power with the generator running. With no load, I found good voltage at the input of both contractors. The odd thing was that there was no voltage at the output of the generator contactor however, there was good voltage at the output of the shore power contactor. It appears that the generator contactor has  been replaced with a SD unit. Next I turned on the front roof AC which drew 14 amps. Then the middle AC came on drawing 30 amps, but I noticed that the inverter/charger had also come on. When I shut that off the amp draw dropped to 16-17 amps for middle. Then the rear AC added another 17 amps. All were running as they should till the charger kicked on bringing the amp draw close to 50 amps. I quickly shut it off and the amps dropped to 34 for the rear 2 AC's and 14 on the front one. When I shut all AC units off, the charger came on pulling 15 amps when the house batteries were @12.8 volts. It's looking like the high amp draw that is tripping the breaker is caused by the charger that is on the same leg as the rear 2 AC's staying in charge mode even when they are fully charged. (That does not happen when plugged into shore power.) I'll check the water tomorrow, as I topped off all eight batteries 2 weeks ago. All appears to run fine on shore power. The standing voltage from the generator with no load is near 116-117 volts, but increases to 120 when a load is detected. It's also puzzling why no power comes through the generator contactor, but does power the coach by parallel wiring to the shore contactor.  Maybe someone can explain it to me.