HWB-138 Universal Joint High Voltage Detector

HASEGAWA HWB-138 is a universal joint high voltage detector built for high voltage installations in the AC 66 kV – 138 kV range. The range covers sub-transmission levels such as 66 kV, 110 kV and 132 kV and forms the upper-middle step of the HWB family.

110 kV is a common high voltage level in many European networks, and in countries that follow UK-origin practice 132 kV is a core transmission level. The HWB-138 is intended for teams that want to handle 66 kV, 110 kV and 132 kV installations with the same equipment. Manufactured in Japan by Hasegawa Electric, it is supplied by HASEGAWA Türkiye, the official HASEGAWA distributor in Türkiye, to customers across Europe.

How does a high voltage detector work?

The HWB-138 is a separate-type detector: the instrument is fitted to the end of an insulating stick and brought towards the conductor to be checked. According to the spec table, the alarm starts at a distance of 5 – 10 cm from the conductor at AC 66 kV. On standby the instrument shows it is ready with a green LED, which switches off automatically after approximately 2 minutes. When voltage is detected, the red LED flashes and an intermittent sound of 80 dB or more is heard. The fact that the flash can be distinguished at 50,000 lux matters for checks carried out in direct sunlight in open switchyards.

HWB-138, HWB-110 or HWB-550A?

	HWB-110	HWB-138	HWB-550A
Operating voltage (AC)	35 kV – 110 kV	66 kV – 138 kV	11 kV – 550 kV
132 kV installation	Outside the range	Within the range	Within the range
150 kV installation	Outside the range	Outside the range	Within the range
Detection distance (spec table)	Not stated	5 – 10 cm (at AC 66 kV)	Not stated

150 kV and 220 kV are above the HWB-138's upper limit. For 150 kV, the HWB-550A can be considered within the family, or the HST-170 among the hot stick options. If you are looking for a different design in the same 66 kV – 138 kV range, see also the HST-138V page.

Technical specifications

• Operating voltage: AC 66 kV – 138 kV, 50/60 Hz
• Detection distance: 5 – 10 cm at AC 66 kV
• Alarm: intermittent sound (80 dB or more) and flashing red LED; green LED on standby
• Construction: separate type
• IP45-equivalent water resistance; impact resistance by IEC 61243-1 pendulum method
• Operating temperature: −10 °C … +50 °C
• 2 × R03 (1.5 V) batteries, approx. 400 g including batteries, supplied with carrying case

Limits of use and safety

Use the HWB-138 only in the 66 kV – 138 kV range; it may not give reliable results on feeders below 66 kV and must never be used at 150 kV or above. Carry out checks with a stick of an insulation class and length suited to the voltage level, maintaining the minimum approach distance set by the site operator. Confirm that the detector works before each task, and do not touch the conductor without earthing even if the result shows no voltage. Our detector inspection guide can help with periodic checks.

Why buy from HASEGAWA Türkiye?

• On projects mixing 66 kV, 110 kV and 132 kV levels, we settle the right HWB model in a single conversation
• We prepare project-based quotations for multi-unit orders for construction sites
• We plan the stick to carry the detector and the transmission line earthing equipment together