Power distribution

[EdBob]

hey Everyone wanted to share a solution to power distribution. I’m an engineer by trade. I got to wondering why this past week while I was at a fantastic RV Park (Northlake RV Park Roanoke TX) running all three AC units during the heat of the day....I smelled something hot. After checking everything, to my surprise, the breakers on one side of my electrical panel were extremely warm....actually HOT. The breakers on the other side of the 50 amp 2 pole master were warm but not hot. Obviously there is a problem. After checking terminations no problems found. No lose connections on the buss bars, neutral buss bar, or ground buss bar. I began to focus my attention on the load distribution.

Currently as shipped from factory:
Phase X 50 amp left side
15 amp washer dryer (used for dedicated outlet for Quartz 1500 watt heater for garage/office in winter only).
20 amp garage AC unit (15K btu 12 Amps 1440 Watts)
15 amp GFI kitchen and outside perimeter
20 Amp Center AC (15K btu 12. Amps 1440 Watts)
15 amp rear cargo utility outlets (current office space with 1500 watt UPS with 500 watt avg load)
20 amp Progressive PD 4500 converter (variable load up to 1500 Watts)

Phase y 50 amp right side
15 Amp bedroom, entertainment outlets. (3 Amps 360 Watts)
20 Amp bedroom AC (15K btu 12 Amps 1440 Watts)
15 Amp water heater (12.5 Amps 1500 Watts)
20 Amp Microwave / Convection (16.6 Amps 2000 Watts)
15 blank
20 blank (fireplace option)

Total load can not exceed 12000 Watts or 6000 Watts per Phase @ 120 volts for 50 amp shore power. 5500 Watts @ 120 volts 45 Amps for generator.

The problem was not running 3 AC units, but rather due to the conversion of my cargo space to an office, I was actually overloading Phase X overall. This would also explain why the office UPS would beep every time the Center or garage/office AC would cycle on. My solution was to move the 20 amp converter and 15 amp rear garage/office utility circuits to Phase Y. In short, problem fixed. No more hot 50 amp breaker on Phase x, no more power drops triggering UPS on AC units cycling on and off, and balanced 23 Amps/ 2750 Watts per leg when running most items, and a new plus. A 5500watt Onan technically has enough wattage to run 3 15K units under the following conditions: Don’t use the electric water heater (switch to propane)
Don’t use the micro. I ran all three AC units yesterday for 3 hours on generator without any issues. Instant starts on AC’s and no sags. No the generator cannot power everything, but in the middle of summer, in TX it is nice to be at a very comfortable 72 degrees when it’s 96 outside in a parking lot running on Generator.

One additional note. To my surprise, the generator does not produce 240 volts across its two 35 amp supply circuits. Meaning the generator is a single pole, single phase setup. So to get the full output potential from it, the load will have to be as well balanced across both 35 amp circuits as possible. I also moved the bedroom outlets and entertainment from phase Y to a 12 volt 1000 watt Inverter. This allows for me to charge my phone, watch TV in bedroom/living room, and keep Dish TV active regardless of which power source I am using.....or not (like boondocking and not running generator). Just some ideas.....
ED

[SloPoke]

What a great detailed analysis...
What kind of Generator are you saying your rig has?

I had done a similar exercise for different reasons. I have added another full 20A circuit on the Y side of our Seneca, so we could plug in our friends 5'er so they did not need to run their 5kW construction genny. We have a 9k Onan diesel and three AC units we found are not able to run on hot days (we shut down our Bedroom AC)

[EdBob]

I have gas ONAN RV QG5500. I am totally surprised you have issues with a 9kw diesel set. The diesel has so much more torque, it should easily start up all three.

[SloPoke]

Originally Posted by EdBob

I have gas ONAN RV QG5500. I am totally surprised you have issues with a 9kw diesel set. The diesel has so much more torque, it should easily start up all three.

It had no problem with starting them... but after a few hours with them all running, the Gen went into error mode overloaded / hot.

[Grumpy]

Just an FYI for those who didn't know, all RV generators are dual single phase 120 outputs that is why they come with 2 seperate neuturals, none are designed as 240v across the 2 phases. The two neuturals are connected together prior to the transfer switch normally.

[Kdevans]

I have need of a utility converter for my 2004 jay flight any suggestions on where to purchase

[Brooksb]

I plan to have a separate power cord when I add 3rd ac. And if I need all 3 on generator, I plan to bring my 3500 watt predator generator to plug into. And just use gas pump to keep it full. Although it would be nice to be able to easily switch the dedicated line for the 3rd ac back over the the campers generator if I was to leave the bedroom ac off during the day. Anybody know how I could do that?

[GraftonGuns]

EdBob, I work in the power generating field (Hydro- Electric) and have seen this very same issue over the years, One phase of a panel extremely hot due to overloading that phase, People need to pay attention when wiring their homes Rv's etc. or need to have a qualified electrician who understands this issue. Thanks for the heads up......