[Archived]

Jon, I have 3 CA’s, and 1 rooftop and no OTR just the dash air. I was assuming that only the rooftop would be set up to run on one of the inverters. It would require a 240 volt inverter to run the CA’s correct? I have 2-120 volt inverters that I assume could not run a 240 device. (Please set me straight if that is not correct) This may come back to what you were saying about how it was originally set up. I guess I didnt realize that it is common to run CA’s off of inverters. I will nail down what is actually wired to run on the inverters. I will follow with finding out how Marathon built it originally. Thanks for the prompts on these points. Jeff

[Archived]

This is a general expression and not specific to your coach.

Inverters are typically 12 or 24VDC volt input, and 120VAC output. Roof air units and Cruiseairs are typically 120VAC powered. If your coach has 240 volt units it is either rare or unique.

The fact the coach has a single roof air and 3 CA units is a very strong indication it has been modified from its original designs because that vintage conversion had roof or CA units, but I know of none that were originally built with both types.

Perhaps an early Marathon owner can verify how your coach may have originally been configured, but it is possible with only driver’s air it may not have been set up to run any CAs from inverter, but to supplement the driver’s air it may have needed the generator. Typically if a roof air has been added it is because a CA quit working and the owner did not want to pay the cost of repair or replacement, or the owner wanted some AC while driving and added the roof air plus may have added an inverter or modified how the inverters were set up so the roof air could operate while driving from inverter(s).

This mystery is going to require someone to figure out what you have. I suspect Marathon can only help you with how the original coach was set up, and is likely to have no knowledge of the alterations that appear to have been made. This puts you at risk unless you are very careful in trying to figure out what you have. As I stated earlier the starting point has to be to follow the electrical circuits from their source and figure out what you have. You need to verify if you have 240V air conditioners. You have to figure out which 120VAC circuits are powered by inverters and are shore or generator power pass through and which are solely powered by shore or generator. I assume you have a transfer switch and that has to be checked and fully understood because that is going to be a factor in how you get power to the devices.

All inverter circuits have to be isolated from one another because I doubt if the inverters are able to sync phases with one another. You have to understand what circuits each inverter serves with 120VAC power. The more you reveal the more it becomes crystal clear your coach has been modified and the safety and quality of those modifications are as yet unknown.

[Allan]

This is excellent general information you have supplied Jon. Thank you for taking your time to do that.

I did know that the roof air was added by a PO per the man I purchased it from. All of the CA units work good. One is not quite as cold as the others but seems to work fine. As to the reason for the addition of the rooftop, you have offered great food for thought relating to why it may have been done and if the power supply logic may have been changed. Also, setting me straight on my assumtion that the CA units are 240 volts has promted me to back up and rethink what is actaully happening. I am in a holding pattern pending the inverter test results but this gives my control freak/ inquisitive mind some homework until then. Thanks again, Jeff

[Bill]

Jeff,

Inverters are great devices and if you understand their basic operating characteristics you may be able to sort some stuff out.

As long as the inverters have 120 volt power to them, they will do two things. They will pass that power to the inverter 120 volt output so it is just passing through, and they will function as three stage battery chargers. When 120 volt power is removed from the inverter input, the inverters stop functioning as a battery charger and use the 12 or 24 volt battery power now coming into the inverter to creat 120 volt power.

As they got newer and technology improved inverters gained capabilities, but their basics have remained.

If you have any questions about your inverters all you need to do is measure output with 120 volts for input, and with only battery power for input.

[Archived]

Jeff,

Not sure if you have reached out to Leon at Marathon in OR. But if you haven’t suggest you give him a call. They are super helpful with support even to non-original owners.

Bill

[Archived]

Bill,

Thanks for the suggesion. I have not called Marathon as of yet. Based on all of the great help I have recieved here I really believe that the inverters are not working correctly. I tested them both while installed in the coach and wired to different batteries and AC power outside the coach. They are definatley not doing what they are suppose to do. I think I will wait until the inverters are repaired and get as much info on what may have caused the failure before making the decision to reinstall them. I am not sure that I could carry my end of the conversation with Marathon with my current knowlede on the systems. This may be a great option for some basic questions on how it was set up and will keep that as an option. If I am stumped after I get information from the inverter Company I will probably take it to someone like East Tennesse Luxury coach that can look at it and have a dialoge with Marathon if needed. Thanks again Bill. Jeff

[Dick]

It has become a favorite pass time for me to read random threads on PC. I have read several long posts which had me thouroughly engaged and inticapating a resoution or lack there of. The threads that just end with no follow up seem to leave me frustrated and dissapointed like I just finished a great novel ony to find that the last page is missing. I probably need to get a life but thats that. It’s probably been discussed here before but hopefully the point will be considered by members posting probems.

Being a begginer Prevost owner I will probaby be of little help to others beyond being able to report back with the outcome of my issues. Hopefully it will help another in the form of a small piece to a similar puzzle and add to the awsome database here at PC.

I recieved 2 new inverters that were covered under warranty from Promariner. After installing the inverters all systems are functioning as intended. The report that I recieved form Promariner indicated that the sensing circuitry was malfunctioning causing the inverter to sleep until a large watt load was inroduced.(Just as Gerald suspected) The inverter electronics and hardware were actually in working order except they would not invert because of a problem with the cooling fans being inop. Note that both inverters suffered from the exact same conditions. It was natural for me to think that if both inverters were malfunctioning in the same manor it was more likely a problem with something in the system other than the inverters. (Jon-Beyond what is logical) This was not the case. They also offered that the loose connection on one of the shore legs could have caused the damage to the sensing circuit. The fans were a known defect from production.

Thanks to Gerald, Jon, Bill and Robertgines1 for input. I truely appreciate your replies. PC and its members are an invaluable resource for Prevost owners.

Jeff

[Jim/Chris]

Thanks for the update. Always interesting to find out what the real root cause of a problem was.

Gerald

[Archived]

Jeff, you get free lifetime dues for providing us with the final outcome. You nailed it by expressing frustration with threads in which a problem is identified, assistance is posted and then there is no feedback on the outcome.

[Archived]

Jeff,

There are many hands-on Prevost owners in central Michigan to get to know.

Ed Roelle

Grand Blanc, MI