HXA-70 Arm-Mounted Proximity Alarm

HASEGAWA HXA-70 is an arm-mounted hot-line proximity alarm built for crews working on overhead lines from 66 kV to 110 kV. It is fastened to the forearm with a band, monitors the electric field around the conductor without contact and gives an audible warning of at least 65 dB when the critical distance is entered. It is the model covering the highest voltage class in the arm-mounted HXA series.

Under normal conditions, on a 66 kV line with a phase-to-earth voltage of 38 kV, the alarm starts at approximately 150 cm from the conductor. This wide warning distance is consistent with the larger safety clearance required at high voltage. The HXA-70 is manufactured in Japan by HASEGAWA Electric and supplied as a genuine HASEGAWA product by HASEGAWA Türkiye, the official distributor in Türkiye.

Where is it used?

The HXA-70 is relevant on overhead lines at 66 kV and 110 kV, above the distribution network. Typical applications:

• Maintenance on poles and towers of 66 kV and 110 kV overhead lines
• Repairs on de-energised circuits where a live circuit runs along the same route
• Insulator, clamp and fitting replacement on substation incoming and outgoing lines
• Warning personnel during aerial platform and crane work under or near lines

Because the device is worn on the arm, the warning continues while both of the technician's hands are busy with tools and materials. The body weighs about 45 g and does not hinder movement even when worn all day.

HXA-70 or HXA-30?

	HXA-6	HXA-30	HXA-70
Operating voltage	AC 6.6 kV – 33 kV	AC 11 kV – 66 kV	AC 66 kV – 110 kV
Alarm start distance	80 cm (standard conditions)	70 cm at 11 kV	150 cm at 66 kV
Sound level	At least 65 dB (at 1 m)	At least 65 dB	At least 65 dB
Battery	CR2032 (3 V) × 1	CR2032 (3 V) × 1	CR2032 (3 V) × 1
Weight (body only)	Approx. 45 g	Approx. 45 g	Approx. 45 g
Dimensions	78 × 82 × 25 mm	78 × 82 × 25 mm	78 × 82 × 25 mm

The three arm-mounted models share the same body and battery design; the difference lies in the voltage class to which the detection threshold is set. If your lines are up to 33 kV, the HXA-6 is more suitable; between 11 kV and 66 kV, the HXA-30. At 66 kV and above, the HXA-70 is the right choice. For crews who prefer to wear the alarm on the helmet, the HXA-70S offers the same voltage class and the same 150 cm alarm distance.

Technical specifications

• Operating voltage: AC 66 kV – 110 kV
• Standard alarm start distance: 150 cm on a 66 kV line (38 kV phase-to-earth), under normal conditions
• Frequency: 50 Hz / 60 Hz
• Sound level: at least 65 dB
• Battery: 1 × JIS CR2032 (3 V)
• Permissible temperature: −10 °C … +40 °C, without condensation
• Weight and size: approx. 45 g (body), 78 × 82 × 25 mm
• Accessory: fastening band

Limits of use and safety

The HXA-70 is a warning device; it is not designed to detect the absence of voltage. Before starting work on lines up to 110 kV, verify the absence of voltage with a hot stick high voltage detector of the appropriate class, then earth the line with earthing equipment. The alarm distance varies with conductor arrangement, adjacent phases and surrounding earthed structures; the minimum approach distance set in the work plan must be maintained regardless of whether the alarm sounds.

Condensation on the body can affect detection, so allow the device to acclimatise in the cool of the morning or when leaving an air-conditioned vehicle. Check the battery at the start of each shift, and use insulating gloves, a safety helmet and all other PPE.

Why buy from HASEGAWA Türkiye?

• Advice based on site conditions when choosing between arm-mounted and helmet-mounted types for your 66 kV and 110 kV line projects
• Quantity-based bulk quotations and commercial invoice for large transmission crews
• Spare CR2032 batteries and fastening bands added to the same order