[Ryan1969Chevelle]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: pxtx</div><div class="ubbcode-body">Basically the VFD takes incoming power and reconfigures/conditions it.

So with single phase, you only have one pole. You need a capacitor to give it a kick to get moving, and in the right direction. Capacitors are a liablility and they also have a recovery time. That might be why they try to keep the motor running and apply the load to the running motor.

If you use a 3 phase motor, the 3 poles allow you to give it direction by which sequence you wire it in. You also have about 30 percent more power during start up, using just line power. So more starting torque, no capacitors and the fact there are thousands of generic 3 phase motors via Granger and other outlets just begins the list of benefits.

mix in the VFD and you can vary the frequency/ hertz. So when starting, maybe you don't want to shock the equipment. Rather than dumping the full 60 hz all at once, the vfd offers options to more gradually ramp the frequency to the full song, which has many benefits. You also have the ability for practically an infinite number of starts per minute- thus eliminating that &quot;thingy&quot; which is questionable right now.

you can basically use your pressure switch and land 2 wires from the switch right to the drive. Contacts close and the drive starts the motor. Motor will be started however you program the drive. We get more sophisticated with plcs and touch screen interfaces, but for your compressor motor needs...I say spec out a generic 3 phase motor and the appropriate ebay vfd. I like the old GE/Fugi and Toshiba drives.

might be a bit of a ramble. Trying to type this between baths for the kids and other bedtime prep. </div></div>

Paul you are speaking my language buddy.

I don't know all the codes of every Muscle car part known to man, but your &quot;ramble&quot; is my bread and butter.

Throw in a line reactor and you will never have an issue.

And I am a Millwright...........Who says Electrical is for Electricians NOPE!!

Ryan