DC current switch question

I am currently looking for a solution to provide proving status of a DC motor. The DC motor I have draws maybe .4 to .5 DC amps. very small. I need to validate that the motor is on before I continue with the rest of my program. My problem is I haven't been able to find any DC current switches that can switch that low. The lowest I have found so far will make at 2.0 amps. I realize i can do multiple wraps on the CT switch but this can be unreliable at best depending on the fluctiation of the current draw. anybody have any ideas on another reliable way i can accomplish this with out using an inline relay or something? thanks for any help.

Have a look at the following product from schneider electric, works between 3ma and 1 amp.

RM4JA31

Here is a screenshot.
I am trying to post from one of those infernal samsung tablet things.

Absolute Process Instruments

You can not "do multiple wraps on your CT"

DC Current is not measurable via electromagnetic flux. (Unless using actively simulated Hall effect transducer)

I would suggest a DC Current trip relay:
APD 1000
APD 1020

These can have up o 900mA input, and digital output for your plc.

OR, if you have spare analog input, you could read the motor current direct into the PLC real time using

APD 4380
These can have up o 900mA input, and 0-10v or 4-20mA output for your plc.

http://api-usa.com/signalconditioners_dc_input.php

You could wrap one of your motor wires around a glass reed switch. These are magnetic, and will switch with a small dc-induced magnetic field. Cheap and simple.

Having said that - are you trying to prove that the motor is rotating? Just because it is drawing current, it does not mean that the motor is actually running.

Is there anywhere you could put a proximity sensor on a moving part to check that actual motion is happening?

I also advocate measuring RPM of motor driven load. A stalled motor draws current but does not rotate.

Dan Bentler

Thanks guys...all of these are good inputs. the first item i am trying to prove i found another way however there are two actuators of which i am reversing the polarity on to open/close. I will need to validate these as well. i believe some of your replies may work for my program.