2003 HR Navigator transfer switch problem?

[Joint Venture]

On our coach we generally do a lot of boon docking and only use shore power periodically. Today I plugged into a 30A single phase receptacle using a 30/50A adapter. All seemed good for a couple of hours so I decided to take a nap. DW decided rather then wake me she plugged in a 1500watt electric heater (12amp draw) due to being chilly. Then later she wanted popcorn and used the microwave (10-14amp draw). Not realizing she had tripped the 30A breaker and was placing a heavy load on the lithium battery bank of two 8D 270AH each battery. I woke up and had a bite to eat and then realized our batteries were being depleted by the sound of the electric heater slowing down. The 30 amp breaker could not be reset due to the breaker being in a locked cabinet and the key was unavailable at the time. I started up the generator, removed the electric heater from service, reduced all electrical demand and after running for two hours the batteries were back at near full charge. Having the breaker reset couple of hours later I can't keep the 120 volts showing on my display panel inside the coach, I hear what sounds like the transfer switch operating after 120v is restored. The volt meters show 120v but after about 30-60 seconds the meter needles starts dropping off to 100 volts and then the transfer switch activates, The breaker never trips and within 3-5 minutes the TS activates again and the 120v is restored but the cycle repeats itself again of voltage dropping and TS activating. Running the generator all seems good, batteries charge, 120v remain constant and TS never switches. I have inspected all the electrical equipment including the Victron inverter, solar charge controller and TS switch itself with nothing suspect. The power cord is on an electric reel that I suspect has slip rings and brushes in order to have the electric motor wind up the cable. Any ideas? 

Edited December 16, 2023 by Joint Venture

[Tom Cherry]

3 hours ago, Joint Venture said:

On our coach we generally do a lot of boon docking and only use shore power periodically. Today I plugged into a 30A single phase receptacle using a 30/50A adapter. All seemed good for a couple of hours so I decided to take a nap. DW decided rather then wake me she plugged in a 1500watt electric heater (12amp draw) due to being chilly. Then later she wanted popcorn and used the microwave (10-14amp draw). Not realizing she had tripped the 30A breaker and was placing a heavy load on the lithium battery bank of two 8D 270AH each battery. I woke up and had a bite to eat and then realized our batteries were being depleted by the sound of the electric heater slowing down. The 30 amp breaker could not be reset due to the breaker being in a locked cabinet and the key was unavailable at the time. I started up the generator, removed the electric heater from service, reduced all electrical demand and after running for two hours the batteries were back at near full charge. Having the breaker reset couple of hours later I can't keep the 120 volts showing on my display panel inside the coach, I hear what sounds like the transfer switch operating after 120v is restored. The volt meters show 120v but after about 30-60 seconds the meter needles starts dropping off to 100 volts and then the transfer switch activates, The breaker never trips and within 3-5 minutes the TS activates again and the 120v is restored but the cycle repeats itself again of voltage dropping and TS activating. Running the generator all seems good, batteries charge, 120v remain constant and TS never switches. I have inspected all the electrical equipment including the Victron inverter, solar charge controller and TS switch itself with nothing suspect. The power cord is on an electric reel that I suspect has slip rings and brushes in order to have the electric motor wind up the cable. Any ideas? 

I’d try a 50A service.  The 50-30A adapters often are the problem.  Investing in a new one is a better test than fixing something that isn’t broke.  Many folks also pull out the shore to max and run there.  No good.  Exercise the reel several times.  That will sort of clean and polish the contacts and rings.

Thats the drill.  Now if you REALLY want an odd ball test….with power off and the breaker turned off on the Generator, open the ATS.  PULL the Shore cord off. Then put the Genny output on the Shore.  The ATS is PROBABLY a NC Shore connection.  So when you start the genny, it is like shore.  The issue….you MUST turn off the MAIN BREAKER in the MH.  Let the Genny run for 5 minutes….then apply power.  Maybe overkill…

Thats about it.  ODDS ARE….Bad Dog Bome….but you need a reliable 50 A service to verify and run for a while…

[Joint Venture]

Well, interesting resolution to my problem. After driving to a campground near me I plugged into 50A service and all worked perfect. Returned to my daughter's home and again plugged into there 30A service after again verifying the voltage was 120V on receptacle. My problem returned with ATS  transferring first to shore power and after the voltage dropped to about 95V transferring back to generator. In my research I picked up on someone else's problem of the inverter/charger causing an ATS to do exactly as mine had done. I turned off the inverter/charger and all my problems disappeared completely. Shore power worked correctly but being concerned that my batteries would not be charged except by solar and parked in a heavy tree area I decided to turn my inverter/charger on in only charger mode. Shore power worked correctly in this mode. Was fat dumb and happy after all this until I sat down to document my results and post on this forum. Quickly learned my Starlink wifi wasn't working. Seems the 120V receptacle was fed purely from the inverter. Turned the inverter/charger to inverter only and 120V power still remained on. Charger is off and I will monitor the charge levels of the lithium batteries daily, presently at 13.21volts. Love the bluetooth control of the inverter/charger. Again I appreciate all the help I receive on this site.

[Tom Cherry]

6 hours ago, Joint Venture said:

Well, interesting resolution to my problem. After driving to a campground near me I plugged into 50A service and all worked perfect. Returned to my daughter's home and again plugged into there 30A service after again verifying the voltage was 120V on receptacle. My problem returned with ATS  transferring first to shore power and after the voltage dropped to about 95V transferring back to generator. In my research I picked up on someone else's problem of the inverter/charger causing an ATS to do exactly as mine had done. I turned off the inverter/charger and all my problems disappeared completely. Shore power worked correctly but being concerned that my batteries would not be charged except by solar and parked in a heavy tree area I decided to turn my inverter/charger on in only charger mode. Shore power worked correctly in this mode. Was fat dumb and happy after all this until I sat down to document my results and post on this forum. Quickly learned my Starlink wifi wasn't working. Seems the 120V receptacle was fed purely from the inverter. Turned the inverter/charger to inverter only and 120V power still remained on. Charger is off and I will monitor the charge levels of the lithium batteries daily, presently at 13.21volts. Love the bluetooth control of the inverter/charger. Again I appreciate all the help I receive on this site.

All Monacos or at least the ones here have the same system as yours.  Read this thread.  It describes how the inverter works.

You have a problem with the incoming power supply.  There is either a high resistance connection on the “House Side” or in the Dog Bone or in the “extension”.

When there is a high resistance connection, the amps go up and the voltage goes down.  Your inverter/charger is not getting sufficient voltage, under load.  Don’t know the brand or model of the inverter p, there are low voltage cut off points and when the incoming AC drops, sometimes the inverter shuts down.  Magnums have setup parameters and you can change that, but when you get down into the 90’s, it aint happy.  It works when there is no load on the inverter as you cut it off. All inverters have internal ATS….so no Inverter ON, no intenal house power. Read the manual for the in inverter.  If you have a Magnum, then it is NOT happy.

The fact that you tested it and it worked and then it works on Generator….this is PROBABLY NOT AN INTERNAL MH issue.  External.  Start with the basics.  New dogbone adapter.  If you are running a 30Amp “extension”, then get a new one.  If that doesn’t fix it, then the breaker and panel and wiring and connections should be inspected and corrected by a qualified electrician.  Also, remember no matter what the downstream load as in a heater or whatever, if the Inverter is charging or trying to charge, it will probably need around 10 amps.  So, incoming 30….usable 30 minus 10 or 20.  If you have a few small loads like TV or whatever….you are overloaded.  

BTW….if you have a Gas/Electric refrigerator and it “automatically” switches to ELECTRIC when there is voltage….that is a 4 - 5 Amps there.  Switch to Propane to reduce the overload.

The charger will usually take MAX.  Again, there is usually a parameter to reduce the “charge rate”.  When on limited voltage, then set the Charge Rate parameter to maybe 30%.

Here is what you might do.  Run the generator for about 3 hours.  If you have a 8KW, you get 35 Amps per side on both Line 1 and line 2.  That will allow the batteries to be charges.  You did that before.  But if the charger goes to BULK and you see maybe 14 V and 80 A then the charger is sucking up your juice. Hit it with a high amperage load….bingo issues.

I have run an AC unit and had more than adequate power for the heaters in a gas refrigerator and still can run TV. BUT…turn on the Microwave, the EMS (Load Shedding) will kill the AC. 

I do NOT think you have an EMS, so you have to learn how to manually manage your loads.  BUT i do wonder if the dogbone or any upstream cords or the 30A service is providing a FULL 30 A and suspect a high resistance connection somewhere.  Fixing what ain’t broke inside the MH ain’t gonna solve this.

[Joint Venture]

As a retired Industrial Control Electrician with extensive knowledge of the subjects you mention I believe you are 100% correct. If I can run everything on generator with no issues but have issues on shore power then the problem is either the "supply" or the equipment used to feed the ATS. Turning off 1 aspect of the inverter/charger is reducing the demand thus the "saving" the supply side from a "dip" in voltage. Thank you Tom for reminding me of what I should have recognized. The extension cord I used is a #10 cord my son in law made up for his parents small camper that uses only 30A service and have no inverter/charger on it. I carry a 30' extension that is #8 and will use it today as I have used it before and had no issues at that location of another son in laws home. #10 is far too light for this coach's load requirements.

PS

My fridge is 12V dual compressor conversion so heavy inverter load, microwave runs purely off inverter and pulls battery voltage of 13.13V down to 11.81V when running on present inverter only, obviously needs charger side online. 

Edited December 18, 2023 by Joint Venture