scottf200
Well-known member
So in my laymen terms: Because of start up load of a motor is it more efficient to run the wipers at low speed instead of intermittent as the motor (I presume) is starting and stopping every X seconds?
Video showing continuous motor running when wipers are on: http://www.youtube.com/watch?v=PMxBKlfQ1IY" onclick="window.open(this.href);return false;
[youtube]http://www.youtube.com/watch?v=PMxBKlfQ1IY[/youtube]
Background:
http://hvac-talk.com/vbb/showthread.php?1125761-AMPS-R-L-A-F-L-A-L-R-A&s=63c441f6ae0620f4f7aac74193a11dd3&p=13654251#post13654251" onclick="window.open(this.href);return false;
LRA - Locked Rotor Amps: The current you can expect under starting conditions when you apply full voltage. It occurs instantly during start up.
RLA - Rated Load Amps: The maximum current a compressor should draw under any operating conditions. Often mistakenly called running load amps which leads people to believe, incorrectly, that the compressor should always pull these amps.
FLA - Full Load Amps: Changed in 1976 to "RLA - Rated Load Amps".
How many watts will a 2.2kw motor draw on starting?
http://answers.yahoo.com/question/index?qid=20130830102851AAjid2j" onclick="window.open(this.href);return false;
Video showing continuous motor running when wipers are on: http://www.youtube.com/watch?v=PMxBKlfQ1IY" onclick="window.open(this.href);return false;
[youtube]http://www.youtube.com/watch?v=PMxBKlfQ1IY[/youtube]
Background:
http://hvac-talk.com/vbb/showthread.php?1125761-AMPS-R-L-A-F-L-A-L-R-A&s=63c441f6ae0620f4f7aac74193a11dd3&p=13654251#post13654251" onclick="window.open(this.href);return false;
LRA - Locked Rotor Amps: The current you can expect under starting conditions when you apply full voltage. It occurs instantly during start up.
RLA - Rated Load Amps: The maximum current a compressor should draw under any operating conditions. Often mistakenly called running load amps which leads people to believe, incorrectly, that the compressor should always pull these amps.
FLA - Full Load Amps: Changed in 1976 to "RLA - Rated Load Amps".
How many watts will a 2.2kw motor draw on starting?
http://answers.yahoo.com/question/index?qid=20130830102851AAjid2j" onclick="window.open(this.href);return false;
Your compressor will draw about six times there normal running current when it starts. So lets get that first.
Assumptions I have to make since you did not provide adequate information are these:
1)Starting current is 6 times running current
2)Operating power factor for this motor under normal load is 0.80
3) The single phase rate voltage to operate this motor is 240 volts
You will have to adjust your numbers based on what the actual figures are.
- Running kVA = kw/power factor = 2200 / 0.8 = 2,750 VA
- Current = 2750vA / 240 volts = 11.46 amps.
- Starting current = 6 * 11.46 amps = 68.8 amps.
- Your inverter must supply this staring current and not drop the supplied voltage any more than 10% or go no lower than 216 volts during start up..
- The inverter rating will have to be about 16.5 kVA for starting this motor load. Especially is the compressor does not have an unload-er valve for the compression pistons.