Model Boat Mayhem

Mess Deck: General Section => Chit-Chat => Topic started by: mersey dave on July 24, 2010, 08:32:12 pm

Title: motor test
Post by: mersey dave on July 24, 2010, 08:32:12 pm

hi all can anyone explain how to  check the amount of amps a motor draws
many thanks dave.

Title: Re: motor test
Post by: funtimefrankie on July 25, 2010, 02:19:10 pm

If the motor is in the boat and connected up to the propshaft with a prop, my method would be to pop it into a test tank..    your bath... Hook up the motor to the battery via an ammeter, this needs to be in series with the motor so the power goes from the battery through the meter to one side of the motor and the other wire goes back to the battery.  The meter will give the reading of the max current drawn.

Hang on to the boat, maybe a two man job depending on the boat and motor.

Another way would be to replace the meter with a selection of fuses to find which blow or not. IE start with say a 5 amp, next a 10 amp etc

Title: Re: motor test
Post by: Martin (Admin) on July 25, 2010, 03:22:59 pm

Also see:  http://www.modelboatmayhem.co.uk/Common/Electrics/Speed%20controlers.htm

Title: Re: motor test
Post by: dreadnought72 on July 25, 2010, 05:18:13 pm

Quote from: funtimefrankie on July 25, 2010, 02:19:10 pm

IE start with say a 5 amp, next a 10 amp etc

Cheaper to go the other way!  %)

Andy

Title: Re: motor test
Post by: Shipmate60 on July 25, 2010, 05:35:24 pm

What motor, voltage and prop size is it?

Bob

Title: Re: motor test
Post by: mersey dave on July 25, 2010, 06:20:05 pm

thanks all now sorted, i am useing an mfa 800 on 12v and a 2.5in prop.
regards dave.

Title: Re: motor test
Post by: Jonty on July 25, 2010, 07:57:47 pm

  As a matter of interest, what figure did you find?

Title: Re: motor test
Post by: mersey dave on July 25, 2010, 08:21:09 pm

hi jonty the reading i got was 7.3 amps, i am very happy with this as i use it in a 43in tug so most of the time the motor runs only on tickover but allways good to have the power in reserve. it runs on a 12v 7amp battery for 3-4 hours depending on wind.
regards dave

Title: Re: motor test
Post by: Shipmate60 on July 25, 2010, 09:30:15 pm

That sounds about right for an 800.
I might rise to 10 or 11 when going from full ahead to astern.

Bob

Title: Re: motor test
Post by: mersey dave on July 25, 2010, 09:40:48 pm

thanks bob that was the next bit i was going to find out.

regards dave.