Your welcome. Don't concern yourself with the momentary trigger out on the projector. Does the relay circuit you have include a latching or (ratchet) relay with a trigger input? If so the trigger input activates the relay and the contacts will stay latched until the trigger input receives a momentary 12 volts again.
Also, your limit switches should be set up to apply the same trigger input to ratchet the relay to kill the motor's power when in whatever resting position raised or lowered. Remember in your design to include the provision to have a set of limit switches just to control the polarity state of the motor and a set of limits to control the latching relay providing power to the associated polarity reversal circuit.
Your limits reset the entire process at the latching relay when it reaches it's resting position and when powering on and off the projector, only power will be applied to the proper polarity reversal circuit becasue of limit switch positions. This will associate powering on to the lower position and powering off to the raised position.
In response to Alan's post...if all the triggers are interlocked, the problem will be that when all relays activat simultaneously upon projector trigger (power up or power down) there will be no synchronization between the lift's position and the voltage polarity to the motor.
