<...like to log the current usage...>

<...not really interested in the actual current value...>

Eh?

Ok that wasn't particularly well phrased but is it not blindingly obvious what I need? I just need to know when the motor/machine is moving or not to calculate total running time over a shift! Having electrical current data exported to excel with a few simple formulas is one way this could be done.

Thanks for pointing that out though, really useful...

Then an energy management system is required. If a proprietary hardware system is not selected, and there are dozens to choose from, then a simple contact monitoring program within a PLC that has retentive timers programmed into it followed by the display of accumulated hours on a screen (without blinding anyone) would be an obvious solution.

Do the motors have fancy drives, or are they just mains powered?

If they're straight off the mains, you could just tap off the output to the motors to drive relay coils - you've then got volt-free contacts which would be easy enough to monitor.

The motors do have fancy drives but I think I've found something ideal for next to nothing, it logs the use of AC motors by just sitting on the housing and detecting the field when the motor is in use, very simple: Click Here for the
webiste if interested

Looks like it should do the job. May get confused if they're servo motors, though, and don't actually get powered off when stationary. Just a thought.

Do the drives not have a data connection? Modbus, Ethernet, Devicenet? If they don't already, the manufacturer might be able to add that functionality to the drives.

If you don't have that, the cheapest way would probably be to use a PLC as PWSlack suggested. That way you only need one device for all the motors rather than one for each.

No matter what hardware you use, if you want to automate the data logging, you will have to have some programming done. PLC programming is fairly easy and a competent programmer is not hard to find.

You could possibly put an hour meter in line with the power supply- that would be the most direct means of getting the information you are after.

There are a few digital multimeters on the market that come with a data logging program.

This will install on any computer then you download the data stored in the DMM volts,amps, temperature etc. you can present this program and data to interested persons.

Fluke has this probably a bit more expensive than others, I use a Brymen BM810 meter cost about $200.00 which has this facility, just a bit of learning curve to set up the meter.

Shop around I am sure you will find something suitable.

I agree with cwarner7_11. If all you want to do is log the running hours of a motor/machine, connect an hour run meter to the main contactor (via auxillary contacts) of the motor/machine.

Very cheap...very simple.