I'm with RS14 EXCEPT the opening statement in this thread is probably what caused the irritation:
I see that it can handle 20-30A, however, I do not understand how much voltage is needed to trigger it...12v maybe?
may have been better said as:
I see that it can handle 20-30 ADC, however, I do not understand how much voltage is needed to trigger it...12 VDC maybe?
It was covered implicitly with the
(Automotive) hint.
I THINK what Ron's concern is that you may be UNAWARE that switches and relays have AC and DC ratings. They also have HP or Horsepower Ratings.
That's the piece that's MISSING and causing concern in this thread.
Now when you bring it back into the old thread we might still say it's unsuitable and you should consider using an automotive external starter relay such as this one:
https://www.autopartswarehouse.com/...093010841W41260599c6350&apwkwd=starter+relays
So, where we are going is that relays/contactors and switches are application specific.
Now, I'll get wierd, because it probably belongs in the other thread and add a Reversing switch as a possibility:
https://www.industrial-electronics.com/motor_control/3h_Reversing-Motors-Drum-Switch.html
So, yea hopefully you'll understand how a relay operates, but realize that it won't be appropriate for your motor load. I do need to re-phrase that: The initial relay in question could be used for reversing as long as the motor is stopped. but it should not be used to start the motor.
So, maybe Ron was looking for something like:
"Can you give me some ideas on how to do ......"
And answer our questions. The more we know, the better we can help.
A final word on "standard". it's very dependent on the industry your in. For instance BLACK is the HOT wire in the US 120 V wiring. Heating wiring uses codes like R Y W G for RED, Yellow, White and Green. Now someone decides we need a C or Common wire at the thermostat, so (what color is it?)
A 24 VDC coil is common in process control systems
A 24 VAC coil is common is Home HVAC systems
A 12 VDC coil is common in a car
A 120 VAC is "common" for industrial control circuits..."in the US"
Split phase 240/120 is "common" is residential (yes, there is 3 phase residential)
I'm using "common" in place of "standard".
Where seeming good logic can go wrong. I have a 2 HP 120 VAC motor and there is 746 W/HP so I can use a lighting tohggle switch rated at 15 A right?
WRONG!!!