Blue Robotics T200 Manual page 11

If the thruster is spinning in reverse of what is desired, swap the connection of two of the
wires.
While testing your thrusters, do not operate them for more than 10 seconds
outside of water (while dry). The bearings require water for lubrication and
may be damaged if the thruster is operated for an extended period of time
while dry. You may also notice a clicking noise or that some thrusters are
noisier than others. This is normal. Because of the tolerances of the plastic
bearings and the metal rotor shafts, the rotor shaft can move slightly in the
bearing causing variation in how different thrusters sound. Any noise is
significantly reduced or eliminated when operated in water.
If you are having problems with thruster operation please refer to the
Troubleshooting
What kind of device can be used as a signal
source?
Pretty much anything that can output the correct PWM signal! The PWM
signals used by the ESC are the same signals commonly used by RC receivers
or to control servos. The following are a few examples of devices that can be
used as a PWM signal source:
Blue Robotics Thruster Commander
section of this guide.