Dear Mark,
We are considering buying a Winnebago Sightseer 35J with two roof air conditioners. But the coach only has 30-amp service with an Onan 5.5 KW generator. Can these two air conditioners run at the same time with only 30 amps?
Mark Says: Most RV manufacturers use some type of energy management system so both roof air conditioners can operate at the same time on a 30-amp system. Our 2006 Bounder 35E is a good example. It will power up one A/C and then the other. Once they are both running it can sense if there's a requirement for more power placed on the system, like somebody making a pot of coffee, and it will shut one A/C down or both depending on the power requirement. When there is no longer a requirement the A/C units automatically start back up.
Many manufacturers use smaller BTU air conditioners. It was no good to have two 15,000 BTU units if you can only run one, so now they might use a 13,500 and an 11,000 BTU unit which a 30-amp system can run at the same time.
Basically what I am saying is most of today's manufacturers offer some type of power management system to operate both A/C units with a 30-amp system. On the other hand most manufacturers have a built-in system to prevent you from using both A/C units and attempt to use the microwave or other power consuming appliance.
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I have a 1999 Winnebago Adventurer with 30 amps and 2 a/c's. I run both a/c's and still have amps left over. With both it only uses about 22 amps and that includes having some small appliances like lights/radio on at the same time. If the RV park is full and everyone is using a/c on a hot day, sometimes the park's breaker will trip. In which case I use one a/c. But the rig can handle both easily.
ReplyDeleteI have an Itasca Sunova 35J myself and can attest to the fact that yes both will run. Winnebago includes the power management system that is described in the forum that will make sure you dont overtax the power. It works extreamly well. If you should say turn on the microwave, it will drop the 2nd AC off unitl its done. Enjoy your unit, as we love ours!
ReplyDeleteSo how do you know IF your 30 amp rig has that energy management system that will allow you to run BOTH air conditioners at the same time? Mine has the switches up to run one with electricity and down to run both WITH the generator running. Nothing about how to run BOTH while being plugged in.....
ReplyDeleteI installed a 2nd A/C unit in our 32' TT, to cover the bedroom (king in the rear) last year. The camper does NOT have any special power management, and I didn't relish putting anything special in to replace what was there.
ReplyDeleteMy solution was to simply run the power line from the new unit separately from the main. I have an extra cord that I can run when I need the 2nd unit.
This is based on 2 premises
1- I don't need the 2nd unit all the time. The primary is ducted, and covers the entire camper under 'moderate' heat conditions.
2- The campground has a power box that provides both a 30amp connection and a 20amp outlet. The camper's 30amp goes to the normal outlet, and the 2nd A/C goes to the 20amp standard 110v outlet.
I've found that 90% of the campgrounds do have both 30 and 20 (usually 2 20amp outlets) with separate breakers for each.
It's less than the elegant solution found in units designed for 2 A/Cs, but it solved my problem with minimal work.
Just because there are two breakers at the box, does not necessarily mean that there is power to run both lines to full capacity. If you are pulling both power from both the 30 amp and the 20 amp outlets you are likely overheating the lines in the ground which will eventually cause them to fail. It can also cause overheating damage to your cables. Most campground power boxes are designed to use either one of the two breakers but not both. IT IS UNSAFE TO ATTEMPT TO GET MORE POWER IN THIS MANNER.
DeleteQuestion why would they put in a 5.5kw generator and only have 30 amp service 5.5kw is for 50 amp service
ReplyDeleteI added the PulseAir switch to replace the original AC control switch to my 1995 Adventurer. It automatically switches the AC from front to rear. When starting up, it runs back and forth on about a 10 minute cycle, then cools as needed. We tailgate for football in a parking lot with no shade, yet this keeps us cool even in late August early September in Alabama. It was well worth the investment for part and labor
ReplyDeleteOne trick I found to run our 15,000 BTU A/C on our Yamaha i2800 was to start the A/C fan first, let it get up to speed, then cut in the compressor by going to "Cool." This avoids having the fan and the compressor trying to start at once. Since the fan seems to run all the time and the compressor cuts in and out, this also avoids having both trying to start when the thermostat cycles. Seems like it would work for two A/Cs too, if their fans and compressors did a staggered start, either manually or automatically. It works for me but YMMV. (Grin)
ReplyDelete