PDA

View Full Version : "our new inverter split gives you 130%"



gwm121
25-10-2009, 03:32 PM
An inverter spec....
A typical for example, ASY24 from Fujitsu, shows nominal 7kw, "(.9-8KW) " Their brochure says "vram increases maximum output of the compressor"

I have asked manufacturers many times WHEN EXACTLY IS THIS INCREASED POWER over the "nominal" power available.
For example, is it.. all the time? for a set period at start up? Answers Ive had allready include, "all the time but not allowed to state as nominal power as doesnt fall into energy efficiency rating", and "all the time that its capable, but cant say when that is". and "thats how inverters work,"

If it IS all the time that the system is capable, how does one find out the conditions that allow this. Would be nice if your replies just say, high heatload on the evaporator, requiring full performance, but im doubting that otherwise why dont they state nominal" and maximum as the same.

nike123
25-10-2009, 09:26 PM
For Fujitsu, if you carefuly read what is writen in service instruction manual, you could find clear description of capacity control of unit.

http://i37.tinypic.com/28atb88.jpg

As you see, there is no secrets in inverter control. But it is certain that is too many uninformed/ignorant technicians.;)
Could you post link to that brochure so I could see what are you referring to as VRAM.

gwm121
27-10-2009, 06:45 PM
THE BROCHURE IS THE LATEST FUJITSU MULIPAGE FOR inverter single and multi splits , with a pic of a guy reclining in a chair and a dandelion, and as usual no ref number or date.. Page 5 refers to vram. (their latest design of inverter). My lack of understanding of nominal v max power concerns all the inverters not just vram of course.

Thanks for posting the service manual section, so ive read it, and take it that after 30 min of operation, and when outside temp is in excdess of 21c (c section) internal fan is high and setpoint more than 2.5 away from room temp, the system will give the maximum not nominal cooling as long as those conditions exist.

So is the answer that maximum power, (which is more than nominal power,) is available anytime you want it after 30 min of operation,, provided ootdoor ambient is high, indoor fan is high, and room temp more than 2.5 degrees away from setpoint.....

gwm121
27-10-2009, 06:51 PM
,,,,oh sorry, now see the significance of 30 min over max frequancy 2,..... so this means the maximum time for max power availability is 30 min only. BUT what it doesnt tell you is what happens then, does max power never apply till the system is reset, or after a period will it have another go for max power again..............