Normally no, you can't manually open the door. The actuator is very strong and won't move. It works on reversing polarity, one way pushes out, flip polarity and it now pulls in. You will need either a timer or micro switch to stop it and a pair of relays to reverse the polarity and of course a 12v power supply. It will keep moving as long as power is applied until it reaches it's maximum length or until you stop it. How hard the door is to open will determine current needed. Don't buy anything with "fishman" on it unless you like paying 3 times what you should.