HST-70L Hot Stick High Voltage Detector

HASEGAWA HST-70L is a hot stick high voltage detector designed for lines in the AC 20 kV – 80.5 kV range. The detector at the end of the insulating stick is touched against the conductor so that the operator can check from a safe distance whether the line is live. Manufactured in Japan by Hasegawa Electric, it is supplied by HASEGAWA Türkiye, the official HASEGAWA distributor in Türkiye, to customers across Europe.

The HST-70L is intended for technical staff working on high voltage feeders at distribution network operators (DSOs), substation maintenance teams and industrial sites. It is one of the three models in the L series and, with a starting voltage of 3000 V ± 600 V, offers a mid-level detection threshold.

Where is it used?

• Feeders and distribution lines: verifying the absence of voltage on overhead lines and feeder outlets above 20 kV before maintenance or fault repair.
• Substations: checking busbars and line outlets after the circuit breaker and disconnector have been opened, before earthing.
• Industrial sites: incoming cubicles and connection points of large consumers supplied at high voltage.
• Commissioning: status checks on newly built lines before and after energisation.

HST-70L or HST-W80L?

The models in the L series are compared in HASEGAWA's common technical table:

	HST-30L	HST-70L	HST-W80L
Operating voltage (AC)	3 kV – 34.5 kV	20 kV – 80.5 kV	20 kV – 80.5 kV
Starting voltage	500 V ± 100 V	3000 V ± 600 V	5000 V ± 1000 V
Dielectric strength test points	1	3	3
Battery / battery life	LR44 × 2 / ~4 h	LR44 × 2 / ~4 h	LR44 × 2 / ~4 h
Weight	Approx. 3 kg	Approx. 3 kg	Approx. 3 kg

The HST-70L and HST-W80L cover the same voltage range; the difference lies in the threshold at which the detector starts to respond. A higher starting threshold generally reduces the likelihood that induced voltage from parallel live circuits produces a false "live" indication. If you are unsure which threshold suits your site, send us your line arrangement.

Technical specifications

• Operating voltage: AC 20 kV – 80.5 kV, 50/60 Hz
• Starting voltage: 3000 V ± 600 V
• Dielectric strength: AC 75 kV per 300 mm of stick for 1 minute, at 3 points
• Leakage current: 0.1 mA or less during the withstand test
• Battery: 2 × LR44 (1.5 V); approx. 4 hours of continuous operation
• Operating temperature: −10 °C … +50 °C
• Weight: approx. 3 kg

Limits of use and safety

Use the HST-70L only within the 20 kV – 80.5 kV range stated on its label; on a lower-voltage line it may not give a correct result. Before every measurement, confirm that the detector works on a known live source or with a suitable voltage detector tester. During the test, hold the stick only by its handle, wear gloves and personal protective equipment rated for the voltage class and observe the minimum approach distances. A "no voltage" result is not in itself a permit to work: the line must then be earthed with earthing sets, in line with the five safety rules of EN 50110-1. As the batteries last approximately 4 hours in continuous use, we recommend keeping spare LR44 cells to hand. For routine checks of the instrument, see our periodic inspection guide.

Why buy from HASEGAWA Türkiye?

• We help you choose between the HST-70L and HST-W80L, matching the starting threshold to your line arrangement
• We prepare quotations for multiple units and team kits, with a commercial invoice
• Suitable testers for checking the detector in the field can be included in the same quotation