HSR-1.5NR Railway Medium Voltage Detector

HASEGAWA HSR-1.5NR is an AC/DC railway medium voltage detector with magnetic earthing, used to verify absence of voltage on AC 6.6 kV and DC 1000 V – 7000 V circuits on railway lines. Because the earth connection is made by magnet, it can be attached quickly to steel surfaces such as the rail, shortening preparation time on site.

The model's key feature is its two-stage indication on the DC side: a green light flashes at approximately DC 350 V to earth, and a red light comes on at approximately DC 750 V. This lets the user distinguish low-level residual voltage as well. The warning is given by a light visible at 8000 lx and an intermittent sound. This model is manufactured in Japan by HASEGAWA Electric; we are the official HASEGAWA distributor in Türkiye.

How does a railway voltage detector work?

First the magnetic earth lead (7 m) is attached to the rail or a suitable steel earth point. The contact tip is then touched against the conductor to be checked. The unit evaluates the voltage between the conductor and earth:

• On AC circuits it gives a light and sound warning at voltages above 2000 V ±20% (50/60 Hz)
• On DC circuits the green light starts flashing at around 350 V ±80 V
• When the DC voltage exceeds the 750 V ±100 V threshold, the red light comes on

This staged design helps you tell quickly on site whether significant voltage still remains on the line after the feed has been disconnected, or only a low-level residue. Typical applications are DC traction supply lines, catenary and AC 6.6 kV distribution circuits at railway installations.

HSR-1.5NR or HSR-1.5NJ?

	HSR-1.5NR	HSR-1.5NJ1	HSR-1.5NJ
Earthing system	Magnet	Clip	Clip
DC operating voltage	1000 V – 7000 V	1000 V – 7000 V	600 V – 7000 V
DC warning threshold	350 V ±80 V (green) / 750 V ±100 V (red)	800 V ±100 V	400 V ±80 V
AC operating voltage	6.6 kV	6.6 kV	6.6 kV
Weight	Approx. 3.2 kg	Approx. 3.2 kg	Approx. 3.2 kg

The deciding factor is the type of earthing point: for a fast connection to a steel rail choose the HSR-1.5NR; if there is a terminal or conductor to clip onto, the HSR-1.5NJ / 1.5NJ1 is more suitable.

Technical specifications

• AC operating voltage: 6.6 kV, 50/60 Hz; starting voltage 2000 V ±20%
• DC operating voltage: 1000 V – 7000 V
• DC starting voltage: 750 V ±100 V (red), 350 V ±80 V (green flashing)
• Earthing: magnet; 7 m magnet-type earth lead
• Warning: light visible at 8000 lx, intermittent sound
• Dielectric strength: AC 14 kV, 1 minute
• 2 × LR03 / R03 batteries; approx. 3.2 kg; carrying case

Limits of use and safety

The scope of the HSR-1.5NR is limited to AC 6.6 kV and DC 7000 V; it must not be used on higher-voltage lines such as AC 25 kV catenary, for which a detector of the appropriate class such as the HST-W80JS must be selected. For an accurate measurement, the surface the magnet attaches to must be clean, unpainted and genuinely earthed. Check the battery condition and the warning function before use.

A flashing green light shows that low-level voltage is present on the line; in that case do not start work, and investigate the source. Once absence of voltage has been verified, the line must be earthed with suitable equipment such as the Type R DC railway earthing hook. Insulating gloves and PPE must be used according to the operator's instructions. More details are in our article on catenary voltage testing.

Why buy from HASEGAWA Türkiye?

• Recommendation of the magnetic or clip HSR version according to the earthing point on site
• Supply of spare accessories such as the magnetic earth lead
• Quotations combining detectors and earthing hooks for railway maintenance teams