Homebuilt ROVs Forum

I bought some 24Vdc motors from an office printers parts Shop ,but every time i use them(at the pool) my Relays(10A-60A) it burns up .
Any one i asked him say that's impossible that a DC motor in load(water) consume more than 10A.

can any one help ?

thanks

How are you powering the motors (voltage?) and what voltage are the relays rated at?

-Steve

Chlorinated water conduct electricity much better than clear water.

Any one i asked him say that's impossible that a DC motor in load(water) consume more than 10A.

Thats bullshit: I have tested brushless-motors in water with (only) 35mm props take at full speed easy 9A. What propellers are you using?
10A is nothing if you want to have some power. My Brushless-units takes 12-15A ...

I think there will be a lot of current you are loosing because of chlorinated water...

What motors you using?

sthone wrote:How are you powering the motors (voltage?) and what voltage are the relays rated at?

-Steve

I power the motor with 48 v and the relay works on 12 v

You have 24Vdc Motors you powering at 48Vdc?

ROVER3D wrote:Chlorinated water conduct electricity much better than clear water.

Any one i asked him say that's impossible that a DC motor in load(water) consume more than 10A.

Thats bullshit: I have tested brushless-motors in water with (only) 35mm props take at full speed easy 9A. What propellers are you using?
10A is nothing if you want to have some power. My Brushless-units takes 12-15A ...

I think there will be a lot of current you are loosing because of chlorinated water...

What motors you using?

the power of mine is totally insulated, Dc motor brush' 1000rpm 24 v

ROVER3D wrote:You have 24Vdc Motors you powering at 48Vdc?

I test it directly to 48 v and it can handle it

So you're running 12VDC motors at 4x the rated capacity, underwater and you're burning out relays.

I think a few of your assumptions are incorrect. I'd go back to the beginning and work through the process again, eliminating anything that pushes the equipment past it's rated capacity and try again.

no no the motors are 24v and by trying it can be 48v, the relay's coil are 12 v

Everything needs to match. Only run 24VDC to the motors. Only run 12VDC to the relays. As said before, you are exceeding the capacity of your equipment. If your power is 48VDC, you will have to convert the voltage for the motors and relays.

Chuck