Installation Instructions for the MOTORIZED Simple Pump System (Scotch Yoke Drive option) page 6
Section 5: Electrical Connection
Notice there is a terminal block on the inside of the stainless enclosure in the photos to the right. Make the necessary electrical connections there.
The first photo shows the terminal block covered by a rectangular stainless steel junction box. This junction box arrives attached to the motorized system with SYD mechanism. In the second photo, it is shown with cover remove, so that the electrical connections can be made.
The junction box has a 7/8″ diameter access hole intended to accommodate 1″ electrical conduit for the two wires feeding the unit with 12VDC or 24VDC power.
Attach your positive and negative power leads to the terminal block so that the final output rotation is counter-clockwise. This rotation direction will provide a constant tightening torque on the driven cam roller and will prevent the cam roller from walking off of the crank arm.
A counter-clockwise rotation direction will also take advantage of the up angle on the scotch yoke and will reduce the amperage draw slightly.
Make sure that the wiring from your power source is at least 16 gauge, and can maintain a minimum of 11.5 volts with the 12VDC motor at a full load of 15 Amps, or 23.5 volts with the 24VDC motor at a full load of 8 amps.
Note that with greater the distance to the power source, higher gauge wire may be required. (You may need professional advice on this.) Also, at 24 volts, line loss is significantly lower compared to 12 volts.