VTA / SYNCRO / CUSTODIAN HV voltage detectors 63–420 kV, wireless phase comparator 1–79 kV and fixed indicator 5–138 kV

VTA / SYNCRO / CUSTODIAN HV voltage detectors 63–420 kV, wireless phase comparator 1–79 kV and fixed indicator 5–138 kV

Country: Spain · Model: VTA / SYNCRO / CUSTODIAN

The VTA voltage detector for 63–420 kV, the SYNCRO wireless phase comparator for 1–79 kV networks and the CUSTODIAN fixed indicator for line voltage of 5–138 kV cover voltage detection and phasing in high-voltage installations. These instruments are used at 6–35 kV and 110–330 kV substations, in outdoor switchyards and switchgear cells, and at network and industrial enterprises.

VTA: electronic HV detector, ranges from 63–150 to 225–420 kV, optical and audible indication, 9 V 6LR61, < 1 µA
SYNCRO: wireless phase comparison 1–79 kV, 50–60 Hz, range up to 50 m, 2.4 GHz, response < 500 ms, UNE-EN 61481-1:2015
CUSTODIAN: fixed voltage presence indicator, phase 2.9–79.6 kV, line 5–138 kV, clamp 22–53 mm, M8, IP65
Installation: VTA, SYNCRO – on an insulating stick; CUSTODIAN – permanently on a busbar/cable indoors

Request a quote All specifications

Technical specifications

VTA	electronic HV detector, ranges from 63–150 to 225–420 kV, optical and audible indication, 9 V 6LR61, < 1 µA
SYNCRO	wireless phase comparison 1–79 kV, 50–60 Hz, range up to 50 m, 2.4 GHz, response < 500 ms, UNE-EN 61481-1:2015
CUSTODIAN	fixed voltage presence indicator, phase 2.9–79.6 kV, line 5–138 kV, clamp 22–53 mm, M8, IP65
Installation	VTA, SYNCRO – on an insulating stick; CUSTODIAN – permanently on a busbar/cable indoors
Self-test	test button (VTA), built-in (SYNCRO)

Specifications are taken from the manufacturer’s technical documentation. Updated 11/06/2026.

Description

The electronic VTA checks for absence of voltage in indoor and outdoor switchgear and on HV lines. The microcontroller and contact detection make it resistant to strong electric fields, and before use the test button checks the whole circuit. The unit switches on by itself when it detects voltage, switches off after a few minutes of inactivity and works from −25 °C. Presence of voltage is shown by a bright red LED and an intermittent powerful audible signal, absence by a green LED that is visible from a long distance. The SYNCRO consists of a transmitter and a receiver on insulating sticks, the phases are compared by a 16-bit microcontroller using a zero-crossing algorithm, and the response time does not exceed 500 ms. The housing is illuminated, so the indication is visible through 360°, and the transmitter separately shows the presence of voltage. The CUSTODIAN is permanently mounted on busbars or cables in switching station rooms of transformer substations and shows the presence of voltage by a light signal at a phase voltage of 2.9–79.6 kV.

How to choose

To check for absence of voltage before earthing at HV sites the VTA is used, with the version chosen by nominal voltage and the stick by the same class. Phasing before paralleling, closing rings and connecting new lines is done by the SYNCRO, which complies with UNE-EN 61481-1:2015 and works in 50–60 Hz networks. The CUSTODIAN is installed where the presence of voltage on busbars must be visible all the time without a portable instrument. For medium voltage of 3–66 kV the same range includes the VTE and VTM, and the personal D-TUERI DUAL alarm complements the detector during work near lines up to 400 kV.

Request a price and lead time

VTA / SYNCRO / CUSTODIAN HV voltage detectors 63–420 kV, wireless phase comparator 1–79 kV and fixed indicator 5–138 kV. We reply within one business day.

Or email office@usk.ua or call +38 (044) 339-50-20.

FAQ

At what distance does SYNCRO compare phases?

The guaranteed detection distance is up to 50 m, including through walls and doors. The transmitter and the receiver exchange data over a 2.4 GHz radio channel.

What battery does the VTA detector need?

A 9 V battery of type 6LR61, and in standby mode the VTA consumes less than 1 µA.

What voltage ranges does the VTA detector have?

The versions cover from 63–150 to 225–420 kV, and the insulating stick is taken of the same voltage class.

How is CUSTODIAN fixed on a busbar or cable?

The clamp opens to 22–53 mm, the connection is M8, and the orientation can be turned by 30° in any direction. The user can replace the contact electrode himself.

What protection rating does the CUSTODIAN indicator have?

IP65 is declared, but according to the manufacturer testing is still in progress, so this value should be confirmed before design.