Re: motor starting relay

John Fields <jfields@xxxxxxxxxxxxxxxxxxxxx> wrote in
news:92epr2dco468v2q9fm11fsh9a77j0sm65h@xxxxxxx:

On Sun, 28 Jan 2007 02:17:42 GMT, "Homer J Simpson"
<nobody@xxxxxxxxxxx> wrote:


"Maxwell" <luv2fly99@xxxxxxx> wrote in message
news:JwTuh.18131$8U4.9385@xxxxxxxxxxxxxxx

Well now, it does have a 5 hp contactor that works off a pressure
switch now. On at 150 psi, off at 175 psi. That contactor makes
connection of the two 120v legs that supply power. But it also has a
spring loaded switch that switches out the starting capacitors at
about 1400 rpm or so, it's a 17XX rpm motor. The 5 hp contactor and
power leads to the motor are something different.

The relay I want to ad would switch on the starting capacitors
immediately when the power is switched on by the existing 5 hp
contactor, and break that connection about 1.5 seconds later. So
although I know the main contactor has to be rated for switching a 5
hp single phase motor, that normally draws 23 amps ( nd has a lock
rotor rating of much much more), I don't know how much amperage is
being supplied through, and has to be broken, by the capacitor
circuit. Now that I think about it, it's only about a 14 or 16 gage
wire, so it would have to be a lot less aperage than the power legs
though the 5 hp contactor. The contactor closes a 30 amp circuit
wired with #10 copper.


Why??? The capacitor is already connected at start up (or it would not
start up). It is disconnected by the spring loaded switch when it gets
up to speed...

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