| Author |
Message |
joe shelton (Littlewind) (67.241.228.45)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 14, 2002 - 8:12 am: | |
I am getting ready to purchase a new genset and was looking at 6.5kw or 7kw. Then a salesman told me that a 5.5kw 46amp unit would be big enough to run my 2 A/Cz.
I figured my total draw would be around 5600kw (including 2 A/Cs @ 1500 each).
So I'm thinking of going with a 5.5kw and saving $700 to $1000. (I can afford the 5.5 but have to save for the 6.5.)
Am I on the right track here?
I tried searching for this subject but I'm afriad I'm am a bit slow.
joe |
FAST FRED (65.58.190.202)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 14, 2002 - 2:41 pm: | |
The problem is that the gen unit will have to start air #2 when air #1 is on.
If you look thru the paperwork from the air cond mfg , you can find the LRS (locked rotor start}.
Usually its 2 or 3 times the run amps.
On my Dometic basement the LRS is over 60 amps!!
With an old style unit like a heavy OHNO usually its not a problem.
With the units with tiny motors that make chop chop electric , it probably won't get #2 started.
So what unit are you looking at, and whats the LRS of the air units you have selected?
Biggest question is will you also have a good ( following) inverter.
If you will ( there expensive & the batts are too) a very small gen set will work just fine , as the inverter will carry the loads for that part of a second as needed.
The best gen set is the smallest that will just do the work needed, it will last the longest.
FAST FRED |
Gary Stadler (Boogiethecat) (68.7.217.217)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 14, 2002 - 8:18 pm: | |
SO my big question is this: Quite often an A/C compressor is never on 100% of the time. They cycle on and off to keep the temp. constant. Mine is usually on less than half the time. Why the heck doesn't someone come up with a controller that lets both AC fans run continuously, but only let the compressor in unit #2 come on if the compressor in unit #1 is off. That way a smaller genset could easily handle them both because they'd time-share and never be on at the same time. It's as simple as a single 110vac relay that disconnects the second compressor as the "preferred" AC kicks in, and a switch to disable the feature when the land-line is hooked up...matter of fact that's how I'm going to operate mine... |
Frank allen (64.12.101.177)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 14, 2002 - 9:41 pm: | |
I have two 13500 roof airs, mesured draw is 12.5 amps each , so the smaller 5.5 should do the job depending on what units you plan on using but id recomend the 7 kw cause you may want to add or change some things later, my 7 kw will run everthing in the bus at the same time , two a/c units microwave and a hotwater heater . i think the unit will produce 66 amps. it is a onan
Frank allen |
FAST FRED (63.208.80.60)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 15, 2002 - 5:21 am: | |
The basement units can be set to operate as you desire.
You can easily purchase a relay from Grangers to do what you wish to rooftops , but there will be some extra wiring that needs to go between them.
You can also rig the same style relay to only allow the electric Hw heater to operate when # 2 air is off.
FAST FRED |
Peter Broadribb (Madbrit) (170.215.33.198)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 15, 2002 - 1:22 pm: | |
Guys,
any thoughts on a gasoline power Kohler Command 20 genset? It comes as a sound attenuated enclosed unit or without the case. Has air intake ducting attached whichever form you order which would draw from the outer side of the bus. The seller says the air outlet is various, which he means it escapes all over the unit and not through any particlular duct.
Says it is an ideal generator for use as an Uninteruptable Power Supply offering seamless power suitable for telecom systems. Cost is $2000 and it's new.
Anyone any knowledge of this unit? Thanks.
Peter. |
joe shelton (Littlewind) (67.241.230.49)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 17, 2002 - 6:26 pm: | |
Mr Fast Fred, I have a Heart Freedom-25 2500 watt inverter/charger. The A/C units are Dometic 13,500 btu with 1530 watt heat strips (which I don't use). The A/C data plate says "Compressor 11 RLA: 54.4 LRA:
Fan Motor 2.5 FLA: 5.8 LRA; 1/5 HP:
I figure LRA = Lock Rotor Amps
But RLA & FLA ??
I was figuring 1620 watts per A/C. |
Henry R. Bergman, Jr. (Henryofcj) (63.224.197.10)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 17, 2002 - 8:43 pm: | |
Your 5.5 will probably run 2 ACs low and cold, but not 2 ACs high and hot.
I am planning on running a 7.5 KW for my 2 roof ACs which will start them even on Vulcan.
Need to figure on 9000 feet and 100 degrees F, plus other coach stuff like a blender. Martini anyone? Henry |
FAST FRED (63.215.237.77)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 18, 2002 - 4:39 am: | |
1600W seems to be about right , so you could power ONE air with the 2500W of inverter going down the road , if your engine has a BIG alternator.
The inverters output style power will determine how happy (powerfull)the air cond is .
Not all inverters run heavy motors with any power.
The true sine wave is excellent , everything else is a great compromise.
I have no idea if the Heart has "co generation " as some models of the Trace can do.
Ask if it can be programmed to help a starting load at the tech line.
FAST FRED |