ac current measurement

[slipstick]

I have a PXI 1002 with a 6025E I/O card, and I want to monitor the current level of some AC going into a set of heaters, to see if any of them are not powering up. Each heater pulls 0.3 amps. So I want to be able to see a difference of 1/3 amp over a roughly two amp range.

My question is what hardware do I interface to the I/O card and what sensor is recommended to accomplish this. The card seems to accept a 5 volt input and so I need the sensor output to match this. The best I've been able to find so far is a converter from ABB (part # 1SVR 040 007 R 0200) but the rep doesn't like me trying to measure the heater current when this unit will have to be powered by the same power outlet as the heaters are on.

Any ideas from the experts?

Tay

[Matthew_W]

 Hi Tay,

 National Instruments does not currently have any current transformer's in our catalog. What I've used in the past we're current transformers that came in two pieces, you would assemble them over a single phase of the AC line. They have a sensitivity potentiometer and provide a switch closure when the current was not there.
Here's a link to one that looks similar to what I used back then.

 Have a great evening.

Best regards,

MatthewW
Applications Engineer
National Instruments

[K C]

Hi Tay,

There are many current clamps on the market for measuring current with . Can't you use one of those current clamps.

Take a look at the Fluke website.

[slipstick]

I am going to contact these guys and see what they can do. Some of it looks promising.

Thanks

Tay