HWB-550 Universal Joint High Voltage Detector

HASEGAWA HWB-550 is a universal joint extra high voltage detector developed for the AC 210 kV – 550 kV range. It sits in the top voltage class of the HWB family and covers the 380 kV and 400 kV levels that form the backbone of European transmission grids in the middle of its range.

The instrument suits TSO substation maintenance teams, contractors carrying out EHV line maintenance and operating staff at large power plants with EHV switchyards. The same range also covers 220 kV, 275 kV and 330 kV networks. Manufactured in Japan by Hasegawa Electric, the HWB-550 is supplied by HASEGAWA Türkiye, the official HASEGAWA distributor in Türkiye, to customers across Europe.

Where is it used?

• 400 kV substations: confirming that conductors are de-energised on line and transformer feeders after the disconnectors have been opened, before earthing.
• 400 kV transmission lines: checks at line ends and temporary earthing points during planned outages.
• Power plant switchyards: EHV connection points of thermal, hydroelectric and large-scale renewable plants.
• 220 kV – 330 kV networks: commissioning and maintenance of 220 kV, 275 kV or 330 kV installations.

At extra high voltage, teams work at a distance from the conductor in large, noisy yards. The HWB-550's intermittent sound of 80 dB or more and its flashing red LED, distinguishable at 50,000 lux, were designed with these conditions in mind. According to the spec table, the instrument gives an alarm when it comes within 5 – 10 cm of the conductor at AC 210 kV.

HWB-550 or HWB-550A?

	HWB-138	HWB-550	HWB-550A
Operating voltage (AC)	66 kV – 138 kV	210 kV – 550 kV	11 kV – 550 kV
150 kV installation	Outside the range	Outside the range	Within the range
400 kV installation	Outside the range	Within the range	Within the range
Detection distance (spec table)	5 – 10 cm (at 66 kV)	5 – 10 cm (at 210 kV)	Not stated

With a lower limit of 210 kV, the HWB-550 cannot be used in 150 kV installations. If your team works in both 150 kV and 400 kV substations, the HWB-550A, which covers both levels with one instrument, may be more practical; if you work only at 220 kV – 400 kV, the HWB-550's range focuses directly on these levels. The HST-550V, with the same 210 kV – 550 kV range, is also an alternative.

Technical specifications

• Operating voltage: AC 210 kV – 550 kV, 50/60 Hz
• Detection distance: 5 – 10 cm at AC 210 kV
• Audible alarm: 80 dB or more, intermittent
• Visual indication: flashing red LED (detection), green LED (standby, switches off after approx. 2 minutes)
• Construction: separate type; IP45 equivalent
• Impact resistance: IEC 61243-1 pendulum method
• Operating temperature: −10 °C … +50 °C
• Battery and weight: 2 × R03 (1.5 V), approx. 400 g including batteries; carrying case

Limits of use and safety

At 400 kV, testing must only be carried out with a stick of sufficient length and insulation for this voltage class, maintaining the approach distances defined in the transmission operator's working instructions. The HWB-550 does not give reliable results below 210 kV, so do not use it at 150 kV or lower levels. Remember that induced voltage may be present at sites with parallel live circuits; whatever the detector result, do not start work until the conductors have been earthed with transmission line earthing sets. Confirm that the detector works before every task.

Why buy from HASEGAWA Türkiye?

• We make the choice between the HWB-550 and HWB-550A for your EHV teams based on your site list
• We recommend a complete equipment package together with EHV sticks and earthing sets
• We provide technical documentation and an invoiced quotation suited to corporate purchasing processes