My brain is arguing with itself about this scenario.
I have 2 escs powering a T200 each. I have a 40v power source and am wrestling with power conversion. Is it possible to wire the esc power inputs in series in order to reduce the power to 20v each esc? This would work if I was wiring 2 DC motors directly, but I don’t know if the same thing applies with an esc between the power and each motor.
Hi Mark,
I don’t think this will work reliably, unfortunately. There are a few issues. The voltage drop across the ESC could vary as the thruster speed changes, which could cause one ESC to see a high voltage and the other to see a low voltage. Also, the signal and signal ground connection for the high-side ESC would be at 20-25v, so if you connected it to a Thruster Commander or other signal source it would burn it out.
If you only have a 40v power source, the best solution would be to use a switching regulator to convert that to a lower voltage. Here’s a power converter that would convert 40v to 12v. This converter has enough current output to handle two T200 thrusters. At 12v the thruster will have reduced power output compared the normally recommended 16v.
The best solution is to use a different power supply!
Hope that helps.
-Rusty
Thanks. Debate settled. 
I have a 12v supply that works reliably now but like you mentioned, 16V would be better.
I tested a different adjustable power supply that works. I ran it for 40 minutes at full throttle (16v) with no issues. There is also a 50 Amp version that might work for 2 motors.
If space is a constraint, the below is a good power supply. We have used these in a point of load system before and one per thruster works well. Just be certain to provide a heatsink for fans if running near maximum power. They can be paralleled if the full power of the thruster is required.
Good luck,
–Peter