HSF-11 Medium / Low Voltage Detector

HASEGAWA HSF-11 is a handheld medium / low voltage detector that checks for voltage on bare conductors by direct contact. It operates from AC 80 V – 11.4 kV, so a single instrument covers everything from 0.4 kV distribution boards to 10 kV-class medium-voltage switchgear (up to 10.5 kV). At approx. 150 g it fits easily in a maintenance kit.

The detector has two threshold levels defined to earth: 65 V ± 15 V on the low-voltage side and 2000 V ± 200 V on the high-voltage side. Made in Japan, the HSF-11 is supplied as a genuine HASEGAWA product by HASEGAWA Türkiye, the official distributor in Türkiye.

Where is it used?

• Building and industrial transformer rooms: Checking for voltage at 10 kV-class switchgear outgoing feeders, busbar connections and the bare points of cable terminations.
• LV distribution boards: Confirming the presence of voltage on the low-voltage side of the transformer, at circuit-breaker outputs and on main busbars.
• Checks after switching: Seeing whether the circuit really is dead after a circuit breaker or disconnector has been opened and before earthing is applied.
• Outdoor sites: IPX3-equivalent protection makes it convenient on pole-mounted transformers and kiosk substations exposed to rain.

The red LED is designed to be visible at 8000 lx, and the audible alarm reaches 50 dB or more at 2 m. The result can therefore be followed clearly in sunlit outdoor switchyards and noisy plant rooms.

HSF-11 or HSE-7G?

	HSF-11	HSE-7G
Operating voltage	AC 80 V – 11.4 kV	AC 60 V – 7000 V
LV threshold	65 V ± 15 V	60 V
HV threshold	2000 V ± 200 V	400 V
Insulated cable	Not applicable, bare conductors only	3000 V through φ5 mm OE wire
Battery and continuous operation	2 × R03, approx. 6 hours	2 × LR44, 3 hours
Weight	Approx. 150 g	Approx. 55 g

If your site has 10 kV-class switchgear (up to 10.5 kV), the HSF-11's range covers that level, while the HSE-7G is limited to 7000 V. If a preliminary check through the sheath and pocket portability are the priority, the HSE-7G remains more practical.

Technical specifications

• Operating voltage: AC 80 V – 11.4 kV, 50 Hz and 60 Hz
• Threshold voltage: 65 V ± 15 V on the LV level, 2000 V ± 200 V on the HV level
• Insulation resistance: 100 MΩ or more between contact tip and handle
• Dielectric strength: 20 kV, 1 minute; leakage current 0.1 mA or less
• Indication: red LED (8000 lx) and min. 50 dB tone at 2 m
• Water protection: IPX3 equivalent
• Battery: 2 × R03 (1.5 V), approx. 6 hours continuous operation
• Operating temperature: −10 °C … +40 °C; weight approx. 150 g

Limits of use and safety

The HSF-11 is specified for bare conductors only; a "no voltage" result taken through an insulated cable sheath must not be relied on. It must not be used on systems above 11.4 kV; for higher-voltage installations such as 15 kV-class and 36 kV-class switchgear, and for points that require reach, choose a hot stick high voltage detector. Because it is a handheld instrument, approach distances in MV installations must be set according to applicable regulations and your company procedures (for example EN 50110-1 where it applies), and PPE such as insulating gloves and a face shield must be worn in full.

Before every use, the light and sound functions should be tested with a voltage detector tester or a known live source. A dead indication from the detector does not replace earthing; after the check, the circuit must always be earthed. For regular inspection intervals, see our periodic inspection article.

Why buy from HASEGAWA Türkiye?

• We review your single-line diagram to assess whether the HSF-11 is sufficient for your 10 kV-class switchgear and LV boards
• We can add suitable HLA testers to the same quotation so your teams can verify detectors on site
• We prepare a single-line quotation with a commercial invoice for instruments to be issued to several maintenance teams