Instrument Voltage Transducer

National Registry N 77712-20

The CHVT-500 is a high-voltage capacitive instrument transducer designed for testing instrument voltage transformers up to 500 kV.

The CHVT-500 is available in some configurations with respect to the accuracy class and rated secondary voltage.

Accuracy classes: 0.05, 0.1

Rated secondary voltages: 100/√3; 100; 100/3; 110/√3; 110; 110/3; 120 V


The CHVT-500 transforms high AC voltage applied to its primary side into low AC voltage on its secondary side with a standard-compliant scaling factor.


The CHVT-500 can be used:
As a reference voltage device in the course of testing (calibration, verification) of instrument voltage transformers rated up to 500 kV and of 0.02 accuracy class (or less accurate)
For high voltage measurements

Basic accuracy specifications



Primary (input) voltage rating (RMS, 50 Hz)

500/√3 kV

Secondary (output) voltage ratings

100/√3, 100, 100/3, 110/√3, 110, 110/3, 120 V

Range of primary voltage measurements (in % of rated voltage)

40 to 120 %

Limits of permissible voltage measurement error (for accuracy class 0.1):
Ratio error δКu

±0.1 %

Phase error Δφ

±5.0 min

Limits of permissible voltage measurement error (for accuracy class 0.05):
Ratio error δКu

±0.05 %

Phase error Δφ

±2.0 min

Test voltage (RMS, 50 Hz) applied to the CHVT-500 during 1 min (kV)

1.32•Unom + 15 kV, where Unom means “rated voltage”

Basic specifications

Mains supply

207 ... 253 V,
49.8 ... 50.2 Hz

Operating temperature range

+10 to +25 °C


2 kg, or less
140 kg, or less



Excessive pressure of SF6 gas:


0.35 MPa


0.25 MPa

Capacitance of the HV Instrument Capacitor of the PCU

40 to 60 pF

UIN load resistance (no less than)

100 kOhm

UIN load capacitance (no more than)

5.0 nF

UIN power consumption (no more than)

10 VA

Time of continuous operation when powered from mains (no less than)

8 hours

Mean time to failure (no less than)

8000 hours

Test Run of CHVT-500

CHVT-500 - Primary Converter (PCU)
The HV test system console when applying 390 kV to the CHVT-500 during an insulation strength test
Testing the CHVT-500 for insulation strength

Delivery package

PCU — 1
Primary Converter (HV instrument capacitor + current-to-voltage converter)
UIN — 1 as a minimum
Instrument amplifier of voltage
Cylinder with SF6 — 1
Compressor — 1
Compressor’s Power Supply Unit — 1
Compressor’s gas pipe— 1
Pressure Reduction Unit — 1
Filter — 1
Set of cables — 1
Three connection cables
Trolley for handling PCU — 1
Transportation box for CHVT-500 — 1
Transportation box for corona protection shield — 1