Yes. The brand new version of the G-5500 with the "DC" at the end is not compatible with anything before it, as they are now using 22V DC to drive the G5500DC rather then a regular G5500 that uses 24V AC. So that means a G5500DC motor is not compatible with a G5500 Control box, and vice versa. As for why they changed their motors to DC, I dont really know. But something to look out for sure.

73 Nick KE8AKW