3000W Chinese Gensets Info.

Dan86300zxt wrote:
Thanx For the info. and confidence Professor.

SNIP

Ahaaaa..... Selecting an inverter to start and run a 13,500 BTU air conditioner - even for a few minutes. That can be like trying to toss a penny into a milk bottle from across the room.

A MSW inverter will work OK with a 120 VAC air conditioner, but a true sine wave with a peak voltage equal to conventional shore power is always better for obtaining full power from an electric motor and reducing the motor temperature. Let me give you an example of MSW inverter usage: I have a 6,000 BTU A/C I reworked to fit into a Dometic rooftop RV case on the front of our fiver. It pulls around 560 watts. I am able to start and run the A/C from a 1200 watt MAXX MSW inverter. But, the A/C has a nice starting capacitor that really helps get things going. The blower fan runs slower on the MSW inverter power and there is a noticeable hummm in the compressor. I am sure the cooling capacity is reduced by about 1,000 BTU using the MSW inverter.

A 3,000 watt MSW inverter "might" start your rooftop 13.5K BTU A/C if your batteries are fully charged, your cables are short and extremely large, the Ah capacity of the batteries is sufficient to handle the inverter surge without voltage drop, and your A/C has the best possible hard start capacitor added to the compressor. You can improve on the power losses by selecting a 24 volt or 48 volt inverter - but the battery bank size remains the same as a 12 volt inverter.

We are talking about a MINIMUM of four series/parallel six volt golf cart batteries, no more than 2' of #1/0 copper cable (3,000 watt inverters use twin cables for each pole) and the batteries floating at around 6.6 volts each to provide 13.2 volts series/parallel. Note this is an additional 350 pounds of dead weight to carry in the trailer not including the inverter and vented case for the batteries.

Inverters larger than 3,000/6,000 watts are available, but they will require even larger cables and battery capacity to provide the needed power for the inverter.

DC to AC inverters typically have a 10:1 power ratio. If the surge or starting current for the 13.5K BTU A/C is 56 amps (typical) you will be pulling 560 amps from your batteries and through your cables. 1 volt may not sound like much, but a loss of 1 volt to the input of an inverter is a pathway to failure for the output and surge capacity of an inverter.

You are going to spend a lot of money - a BIG lot of money - on the inverter, batteries and wiring. Truthfully, you would be way ahead of the game to run a pair of 2,000 watt Honda inverter generators and drop one after the A/C is running or run a single 3,000 watt generator.

Contrary to some beliefs for feasibility - I run a single Champion 40008 that powers my 15K BTU rooftop A/C that is ultimately quieter than a Honda inverter or MotorHome Onan built-in generator. I carry 1,600 Ah of AGM batteries in the bed of the Volvo that plug into the camper when inverter power is needed. I can run the 6,000 BTU A/C all night off of the 1200W MSW inverter and the large battery bank making it possible to sleep cool on a hot, humid night when even quiet generators are not allowed. Of course, the battery bank weighs over 1,300 pounds. This would be an issue for a PU or in a camper. But, it is nothing for the Volvo to carry around. In fact, the added weight helps overall performance since the computer manages power from the engine based on load (Load Based Speed Control). Sorry, but I sometimes need to gloat a little :B

Compare your dollar to dollar investments and added weight/space consumed and you may want to drop the idea of using the battery powered inverter and just go to a second or larger generator.