HWB-550A Universal Joint High Voltage Detector

HASEGAWA HWB-550A is a universal joint high voltage detector that brings a very wide range, AC 11 kV – 550 kV, into a single unit. While the other models in the HWB family focus on a specific voltage class, the HWB-550A offers one operating range extending from medium voltage up to extra high voltage.

For European networks, this means that 11 kV, 20 kV and 33 kV distribution, 110 kV – 150 kV and 220 kV transmission and the 400 kV EHV level all fall within the scope of the same instrument. Levels between 138 kV and 210 kV, such as 150 kV, fall outside the range of every other HWB model, which makes the HWB-550A the family's key model for teams working in substations at those levels. Manufactured in Japan by Hasegawa Electric, it is supplied by HASEGAWA Türkiye, the official HASEGAWA distributor in Türkiye, to customers across Europe.

Where is it used?

• 150 kV substations: checking absence of voltage on feeder, busbar and power transformer connections before earthing.
• Multi-role maintenance teams: teams who work in a 33 kV distribution substation and in 132 kV and 400 kV switchyards within the same week.
• Power plants and industrial HV installations: maintenance at sites where the medium and high voltage sides are in the same yard.
• Contractors: substation projects requiring checks at different levels during commissioning.

On detection, an intermittent sound of 80 dB or more and a flashing red LED work together; the flash can be distinguished at 50,000 lux. The green standby LED switches off automatically after approximately 2 minutes.

HWB-550A or HWB-550? The whole HWB family

Model	Operating voltage (AC)	Typical system levels covered
HWB-35	6 kV – 35 kV	10 kV, 11 kV, 15 kV, 20 kV, 33 kV
HWB-110	35 kV – 110 kV	66 kV, 110 kV
HWB-138	66 kV – 138 kV	66 kV, 110 kV, 132 kV
HWB-550	210 kV – 550 kV	220 kV, 275 kV, 400 kV
HWB-550A	11 kV – 550 kV	11 kV, 20 kV, 33 kV, 150 kV, 220 kV, 400 kV

All models in the family share the same alarm system, IP45-equivalent protection, battery type and approximate weight of 400 g; the difference is the voltage range. Narrow-range models suit teams working intensively at one level, while the HWB-550A is a more flexible solution for teams that move between levels. For medium voltage alternatives, see also the HWA-33P page.

Technical specifications

• Operating voltage: AC 11 kV – 550 kV, 50/60 Hz
• Audible alarm: intermittent sound, 80 dB or more
• Visual indication: green LED on standby, flashing red LED on detection (distinguishable at 50,000 lux)
• Water resistance: IP45 equivalent
• Impact resistance: pendulum method, IEC 61243-1
• Operating temperature: −10 °C … +50 °C
• Battery: 2 × R03 (1.5 V); weight approx. 400 g including batteries
• Accessory: carrying case

Limits of use and safety

A wide range does not mean the stick is suitable for every level: for checks at 150 kV or 400 kV, the insulating stick used must have sufficient length and insulation for that voltage class. Do not use the instrument in installations below 11 kV, for example 6 kV or 10 kV switchgear; the HWB-35 is suitable for these levels. Before each use, confirm that the detector works, follow the site's approach distance rules and earth the conductors after a "no voltage" result. For more on this topic, see our electrical safety equipment checklist.

Why buy from HASEGAWA Türkiye?

• For 150 kV-focused installations we assess the HWB-550A together with your existing stick inventory and identify missing items
• We prepare quotations for multi-unit purchases to be distributed across regional depots or projects
• On request, we provide a comparative selection table against the narrow-range models for each level