POG Member Finally Acquires NICE BUS!

[Jon Wehrenberg]

Fred, Just a comment on the Cruise Air loads. Each of mine draws approximately 13 amps. Start up the current draw may spike at as much as 35 amps or thereabouts, but it is momentary. These values are at 120 volts, at lower voltage such as on some poor shore power outlets you will see higher amps.

Shore power is 50 amps at 120 per leg or 100 amps at 120. Our 20 KW generators actually make more power available (167 amps) so running four cruise airs at one time will not even be a challenge. If your generator bogged down under that load it is likely it has only seen light usage. If you run it often under reasonably heavy loads it will clean up the carbon from running lightly loaded and it will perform much better. Don't be surprised to hear and feel it stumble as you load it up, but expect its performance to be smooth and powerful as it gets more and more exercise, especially heavy loads. Avoid running a generator for long periods lightly loaded.

Even when hooked to 50 amp shore power running all four Cruise Airs will be a challenge. If you have the HW heater it will draw about 9 amps. Just the refrigerator and the typical small loads we never think about will add up to about 5 amps, and if throw on a bunch of lights your inverters will ramp up the charge to your batteries and can easily add 15 or 20 amps to your current draw. With four Cruise airs running on shore power you can see how easy it will be to trip a shorepower breaker.

I limit my current draw by managing my power to a maximum of 40 amps, aiming for less if practical. 50 amp breakers (all size breakers actually) are good for continuous loads up to 80% of their rating, and over that the risk of tripping a breaker goes up significantly. So whenever I am in doubt about the shore power I do not hesitate to use the generator because it will give you about 83 amps per leg.

[flloyd]

Fred, Just a comment on the Cruise Air loads. Each of mine draws approximately 13 amps. Start up the current draw may spike at as much as 35 amps or thereabouts, but it is momentary. These values are at 120 volts, at lower voltage such as on some poor shore power outlets you will see higher amps.

Shore power is 50 amps at 120 per leg or 100 amps at 120. Our 20 KW generators actually make more power available (167 amps) so running four cruise airs at one time will not even be a challenge. If your generator bogged down under that load it is likely it has only seen light usage. If you run it often under reasonably heavy loads it will clean up the carbon from running lightly loaded and it will perform much better. Don't be surprised to hear and feel it stumble as you load it up, but expect its performance to be smooth and powerful as it gets more and more exercise, especially heavy loads. Avoid running a generator for long periods lightly loaded.

Even when hooked to 50 amp shore power running all four Cruise Airs will be a challenge. If you have the HW heater it will draw about 9 amps. Just the refrigerator and the typical small loads we never think about will add up to about 5 amps, and if throw on a bunch of lights your inverters will ramp up the charge to your batteries and can easily add 15 or 20 amps to your current draw. With four Cruise airs running on shore power you can see how easy it will be to trip a shorepower breaker.

I limit my current draw by managing my power to a maximum of 40 amps, aiming for less if practical. 50 amp breakers (all size breakers actually) are good for continuous loads up to 80% of their rating, and over that the risk of tripping a breaker goes up significantly. So whenever I am in doubt about the shore power I do not hesitate to use the generator because it will give you about 83 amps per leg.

Thanks for that very informative advice. I hadn't thought about the Kohler engine until now. I have to admit that I gulped hard when I heard the Kohler strain the way it did.

I have another problem which I confirmed with Liberty on Friday and that is my Line 1 ammeter is bad. At times, it registers as much as 60-80 amps which shouldn't be possible. At most times it reads 2x what the Line 2 reads, even when they have substantially similar loads (e.g. 2 cruise airs on each side). Liberty suggested that I unload both lines and see if both meters went to zero. They did (nearly) and so that looked good. It looks like fixing the panel meter would be very difficult since it would require some very heavy lifting (refrigerator) in order to get to the back side of the panel.

Another thing that surprised me was that when I turned off both inverters, the voltage display went to zero. I would have expected them to indicate the AC output voltage at all times since we were still connected to shore power when I did the test. It didn't make any sense to me. I would think that the two volt and amp meters would be on the output side, right ahead of breaker busses. Perhaps they're using a signal from the inverter to measure voltage and current, however, the Liberty guy did tell me that the ammeter had a typical toroid core pickup on each AC line. I need to know more about this.

[Jon Wehrenberg]

You should be able to easily access the ammeters by removing the breaker panel. I think it has about six screws.

As to the inverters, Liberty provides a breaker for each and the actual wiring from the breaker is two cables, with one going to the inverter transfer switch and the second going to the charger circuit. The small switch on the annunciator panel shuts off the charger/inverter function, but still enables shore power bypass. When your shore power went to zero it is likely when you turned off the breakers which opened the circuit so no power went to the inverters or the bypass relays.