T200 Consuming Low Current @ 15V

Hi,

I have got T200 Thruster and ESC(OLD) from Bluerobotics and trying to run from Arduino.

I am able to successfully run the thruster. But problem is the thruster only consumes the current of 10.5Amps with the supply of 15VDC with the command 1900.

We have fixed the thruster to a metal Sheet and placed is inside a bucket for testing(Picture attached for your reference)

. We tested the speed by increasing the command in the step of 40. The current increases for every step, but at the end (1900) the current consumed is only ~10.5Amps.

We are expecting the thruster to consume approximately 22Amps and produce the thrust of ~50N. But the current being consumed only half of what we are expecting.

Kindly confirm if there is something which we are missing out.

Best Regards,
Shivaraj.N

Hi Shivraja,

The performance characteristics and specifications of the T200 are all taken in static (bollard) thrust conditions. This means that water velocity at the inlet is zero.

In the setup you have there, once the thruster is running the water will begin to circulate, and thrust/current draw will decrease as water inlet velocity approaches water exit velocity.

There is nothing wrong with your thruster or setup here, performance is as would be expected at speed.

-Adam

Hi Adam,

Thank you for your feedback.

We have actually tried these thrusters on our boat(Bollard Pull Test). Please find the below picture.

Here also we got the same results(each Thruster is consuming only 10-11 amps of current maximum). And the total thrust from two T200 thrusters is about 50N(Our Aim is to get the thrust of 100N). To confirm these results of the boat we did the test on the bucket. Where again we ended up getting only 50% of the Current.

Kindly confirm if the Bollard test which we did will give us accurate results or not? or should we change the mechanism?

We are also planning to do a test on the bucket as per the youtube vedio on the below link.

We hope that the thruster will provide good results on this test. kindly confirm If any changes to be made for the mechanism, or the same mechanism is good enough.

Also please confirm what is the maximum time that these thrusters and ESC can run on full load? without damaging the Thruster or the ESC.

Looking forward for your comments.

Best Regards,
Shivaraj.N

Hi Shivaraj,

The setup you have there will not accurately measure thrust, the force sensor is at an angle, and you will need to take this into account. I’m also not sure how you supporting ropes are set up there, they may be taking some of the load as well. Your force sensor should lie perfectly parallel to you thrust vector for an accurate reading. Under the best conditions, a T200 can generate up to 49N thrust at 16v. At 15V, you are unlikely to achieve 100N with two T200s.

What power source are you using, and are you sure it as well as all your power distribution lines can handle the current without significant voltage drop? According to you description, this is the behavior I would expect if you were using a power supply that could not provide full current, and/or there is significant voltage drop on the way to the ESC/ thruster. I have seen power switches cause this before. With two T200s, you should make sure your power supply can provide at least 60A constant current with minimal voltage drop.

If you’re running at 16V or below, the thrusters can be run indefinitely at full throttle. The ESC will shut down if it gets too hot, but this shouldn’t be an issue unless you have it in an insulated closed space with no cooling.

-Adam