I've decided to call RL2 a "latency control relay". this is because it LOOKS like it does nothing, but it was found that when the motor went into reverse there was a 10th of a second or so when the motor would go forward and then into reverse while the coil of RL1 would be pulling the contacts together when the motor was reversed. So RL2 was added for the properties of the time it takes for the contacts to close when power is added to the coil. Therefore as power from RL1's contacts are applied to the coil of RL2, both relays contacts are mode at the same time so power is applied to the motor at the point that RL1 has made its mind up which way to turn the motor, eliminating this latency problem.
RL3. This was added to the door design to allow a change in speed as the door got to the mid open/closed point, this speed change is latched by a magnet riding in the centre of the door that closes the reed switch momentarily latching RL3 and putting the 10 ohm 7 watt resistor in series with the motor.
