I want to measure three phase ac parameters such as voltage, current power factor, etc which daq device will serve the purpose.

[321hanan]

I want to measure three phase ac parameters such as voltage, current power factor, etc which daq device will serve the purpose at lowest cost.

[johnsold]

It depends on what you will be doing with the data, how fast you need updates, and how much accuracy and resolution is required.

In any case the transducers necessary to change from line voltages and currents to values suitable (and safe) for measurement with DAQ devices may cost more than the DAQ device itself.

Lynn

[321hanan]

What can be the safe limit for the DAq Device...

[johnsold]

Most DAQ devices have +/-10 V input ranges with respect to ground.  There are specialty devices with other ranges of course. 

You need to consider not only the voltage ranges, but also safety isolation and transients which often occur in power systems.

Lynn

[321hanan]

What device will u suggest for 3 phase measurements

[321hanan]

Infact I am a university student of bachelors and i do not know much about the labview. Some one told me to do this project. Do you think that it can be done in a low range of money(max 200 $). kindly help me so I can think of any other way if it is not possible. Thanks

[johnsold]

There are very few if any DAQ devices which cost less than $200. Suitable potential and current transformers or other transducers are not inexpensive either.

Does your university electrical laboratory have any transformers or transducers you can use?

It sounds as though you have little experience with power systems. THE VOLTAGES AND CURRENTS USED IN THREE-PHASE POWER SYSTEMS ARE DANGEROUS! CONTACT WITH THESE CIRCUITS CAN RESULT IN DEATH OR SERIOUS INJURY. INCORRECTLY CONNECTED OR UNSUITABLE EQUIPMENT MAY BE DAMAGED OR DESTOYED! If you do not have training in the safe use of such equipment, get training before you attempt to do any measurements.

Lynn

[johnsold]

You asked about alternatives.  What is the purpose of these measurements? What will you do with the data after you get it? Could you do some thing with a single phase system?

Lynn

[321hanan]

I am thinking to do this as my project for our electrical machines laboratory. 

[johnsold]

Check with the person in charge of the laboratory. A machines laboratory should have transformers and possibly other transducers.  Find out what is available. The person in charge may also know of other resources at the university or through local companies who would assist.

Lynn