HST-550V Universal Joint High Voltage Detector

HASEGAWA HST-550V is a universal joint high voltage detector designed for extra high voltage installations, attaching to a common insulating stick via a universal joint. It operates in the AC 210 kV – 550 kV range, which covers 220 kV and 275 kV, and the 380 kV and 400 kV levels used for Europe's main transmission grids sit in the middle of it. It is used by transmission substation operating teams, EHV line maintenance crews and switchyard staff at large power plants.

Indication is given by an intermittent sound of at least 70 dB and a red LED visible at 8000 lx. The instrument is manufactured in Japan by Hasegawa Electric and supplied, with a commercial invoice, by HASEGAWA Türkiye, the official HASEGAWA distributor in Türkiye, to customers across Europe.

Where is it used?

• 400 kV substations: verifying the absence of voltage on line, busbar and autotransformer connections after the disconnector has been opened, before earthing.
• Transmission line maintenance: checking the work location during planned outages before insulator string, spacer or conductor repairs.
• Power plant switchyards: pre-maintenance checks at the EHV connection points of thermal, hydroelectric and large-scale renewable plants.
• Commissioning: site checks before and after first energisation of newly built EHV feeders.

HST-550V or HWB-550?

	HST-550V	HWB-550
Operating voltage (AC)	210 kV – 550 kV	210 kV – 550 kV
Detection distance	Not stated in the data sheet	5 – 10 cm (at AC 210 kV)
Audible alarm	At least 70 dB, intermittent	At least 80 dB, intermittent
Visual indication	Red LED, 8000 lx	Flashing red LED, 50,000 lx; green standby LED
Water resistance	IPX4 equivalent	IP45 equivalent
Battery	2 × LR44 (1.5 V)	2 × R03 (1.5 V)

The voltage range is the same. The HWB-550 offers higher sound and light levels and impact resistance tested by the IEC 61243-1 pendulum method, while the HST-550V is a simpler, more compact solution. You can also ask about the HWB-550A, the other option in this class.

Technical specifications

• Operating voltage: AC 210 kV – 550 kV, 50/60 Hz
• Sound: at least 70 dB, intermittent
• Light: red LED, verifiable at 8000 lx ambient light
• Water resistance: IPX4 equivalent
• Temperature range: −10 °C … +50 °C
• Battery: LR44 (1.5 V), 2 pcs
• Accessory: storage case

Limits of use and safety

The HST-550V is not suitable for installations below 210 kV. In 132 kV or 150 kV switchyards, choose a detector of that class such as the HST-170. The safe approach distance at 400 kV is very large; the length and insulation class of the stick carrying the detector must suit this voltage, and the stick must only be used when dry and clean. Before and after use, confirm that the detector works on a source known to be live or with a suitable voltage detector tester. Take the proximity of neighbouring live feeders into account during testing, and allow only authorised, trained personnel to carry out the work. Once the absence of voltage has been confirmed, do not start work until earthing has been applied with transmission line earthing sets.

Why buy from HASEGAWA Türkiye?

• We plan the right detector combination with operators running both 400 kV and 132 kV – 150 kV installations
• We quote transmission line earthing sets in the same project, bringing supply together in one package
• We prepare formal quotations supported by data sheets for public and private sector tenders