The ACCUVAR family of VAR controller consists of one product, with ACCUVAR as the base model. The ACCUVAR is Microcontroller based, with designs that have been field proven for more than fourteen years. The main features of the VAR controllers are:

Comprehensive Polyphase Measurement

ACCUVAR is three phase measuring controllers, and hence need three CT inputs from the mains and also all the three phase and neutral connections. So, in addition to accurate control of VAR, this model also provides comprehensive electrical measurement. The parameters measured and displayed (depending on model selected ) are all voltages, currents, power factor, all powers and all energies, average PF maintained since last reset and THD figures for voltages and currents.

Ease of Installation

ACCUVAR has an autosense feature, which senses the sizes of the capacitor banks connected on each stage automatically. No need to programme C/K or bank sizes manually.

Low current operation

Since there is no fixed sequence of switching capacitors, if very small capacitor banks are connected, this controller senses down to 1% of the main load and takes corrective action.

Intelligent Control

The control parameter is VAR, and not PF. Target PF value is just used to calculate the capacitive VAR required to be added/removed to achieve the desired PF. e.g. If the target PF is unity, means that the target VAR in the system is zero.

If system KVAR is 200 lagging, then the controller needs to add 200 KVAR of capacitor banks to reach zero VAR.

The calculation of the reactive power in the system is done by taking instantaneous samples of all voltage and current waveforms, in all four quadrants. These values are then subjected to DSP techniques to add a frequency independent 90° phase shift to current samples. The product of these voltage and current samples then generate signed VAR value. VAR controller then takes into calculation the prevailing system KVAR, the prevailing bank KVAR and the bank sizes of each stage, and then switches ON/OFF the combination which is closest to the needed VAR.

Comparison Chart

Feature Description ACCUVAR(Opto-isolators) ACCUVAR
No.Of Stages (Relay outputs) 5A@ 230 VAC, Resistive load. 15 15
ALARM on PF Value   Y Y
Rs 485 Port (Option) Supporting MODBUS-RTU protocol, for integration with SCADA/EMS Y Y
Fast Thyristor Outputs Switching - Y -
LED Stage Indication   Y Y
LC Display   16x1 16x 1


Type Name Statistics
Input Supply Three Phase and Neutral of a 3P4W system
Voltage Direct Voltage Input : Up to 300 V L-N
Burden: 0.5 VA
Current Secondary Current Input: 5A or 1 A (To be specified at the time of ordering)
Range of Reading: 0 - 5000A
Burden: < 1.0 VA
Overload: 5A CT = 6A RMS Continuous
1A CT = 1.2A RMS Continuous
Power Supply Self Powered from mains Wide operating Voltage
SMPS: 80 VAC - 480 VAC, 50-60 Hz
Output Relay Switching Voltage: Max. 250 VAC
Switching Power: Max 1000W
Expected Mechanical Life: >10 x 106 switching operations
Expected Electrical Life : >4 x 106 switching operations @ (Load = 200 VA, CosØ = 0.5)
Measurement True RMSBasicParameters Voltage(Volts L-N: VRN, VYN, VBN) Accuracy: 0.5% of Reading
Current(Amps IR, IY, IB) CT Ratio: Site Selectable
Accuracy : 0.5% of Reading
Capacitor Current  
Line Frequency 45 to 55 Hz, Accuracy : 0.3% of Reading
Power Active Power (P) Accuracy : 1.5% of Reading (For IPFI>0.9)
Reactive Power (Q) Accuracy : 2.0% of Reading (Between 0.5 Lag to 0.8 Lead)
Apparent Power (S) Accuracy : 1.0% of Reading
Power Factor Accuracy : 1.0% of Reading (IPFI>0.5)Range of Reading : 0.05 to 1.00 Lag/ Lead
Energy Total Active Energy (KWh) Range of Reading : 0 to 99999999.9 KWh
Accuracy : 0s as per IS 13779
Total Apparent Energy (KVAh) Range of Reading : 0 to 99999999.9 KWh
Accuracy : 1.0% of Reading
Misc. Cap. Bank KVAR
Run time
Miscellaneous Dimensions Bezel 144 X 144 mm
Panel Cutout 138 X 138 mm
Depth ofinstallation 55 mm
Depth ofinstallation 76 mm with Bezel
Operating temp 10° C to 50° C
Weight 0.82 Kgs (Approx.)
Min. Operating Current 1% of CT primary