Dynamometric-instruments are used for measurement of active, reactive & absolute power in 1 Phase & 3 Phase systems for balanced / unbalanced load conditions. Watt & Var instruments incorporate current coils, which are connected in series with the load & pressure coils of fine wire gauge, which are connected across the load. These instruments work on “Air cored Electro-Dynamometric” principle.
Power Factor meter incorporates two pressure coils one with non-inductive resistance in series & other with capacitance in series & are cross connected. The deflecting torque produced is proportional to the phase angle between current & voltage vectors. The pointer rests anywhere on the scale when meter is not connected in the circuit, as there is no controlling torque.
- Scale : Non Linear. Side zero or center zero are available.
- Enclosure : Sheet Metal (Black painted).
- Terminal protection : Shrouded terminals to protect from accident. (on request).
Electrical Specifications :
- Type : Dynamometric.
- Operating Voltage : 75V to 500V for 1 Ph. 110V / 440V – PT secondary for 3Ph.
- Burden : <1.25VA upto 75V, <2.5VA 100V to 150V, <5VA 200V to 300V<10VA 350V to 600V
- Operating Current :0.5A to 10A for 1 Ph. 1A / 5A – CT secondary for 3Ph.
- Burden : <5VA upto 5A, <10VA upto 10A.
- Frequency : 45 ~ 65Hz. (400Hz. on request).
- Accuracy : Class 1.5 for Watt / Var /. 2° for PF.
- Insulation Resistance : Greater than 20M Ω at 500V DC
- Dielectric Test : 2kV RMS for 1 minute.
- Overload Continuous : 1.2 times
- Overload Short Time : 2 times VN /10 times IN for 5 seconds.
- Operating Temp : -10°C to 55°C
- Storage Temp : -20°C to 70°C
- Humidity : Up to 95% RH
- Conforms To : I.S. 1248 / I.E.C. 60051(Part 3) for WATT / VAR , (Part 5) for PF.
Mechanical Specifications :
Table No. 1 (For Depth : in mm)
Table No. 2 (For Weight : in approx. Kg)
# Note : The connection diagram label is affixed on each meter.
Connection Diagram :
Ordering Information :
1) Type 2) Size, Parameter, Phase & Element and Range 3) Operating Voltage & PTR 4) Operating Current & CTR