Medium / Low-Voltage Detectors

Medium / low-voltage detectors allow checks across a wide range, from low voltage up to medium voltage, with a single device. Pole-top crews on distribution networks, technicians maintaining compact substations and industrial sites with their own MV distribution are the main users of this group. The models range from a pocket-sized hand-held detector to telescopic designs and a dual-purpose AC/DC model.

The first step in selection is to establish the highest nominal voltage of the network you work on. The upper limits of the models range from 7 kV to 36 kV; a 6 kV network and a 33 kV distribution line call for different models.

Which model?

Model	Operating voltage	Typical use
HSE-7G	AC 60 V – 7000 V	Hand-held, approx. 55 g; pole-top telecom and network crews
HSF-11	AC 80 V – 11.4 kV	Checks on bare conductors; networks up to 11.4 kV
HSS-25B1	AC 80 V – 25 kV	Telescopic type; medium voltage up to 25 kV
HSS-36B1	AC 80 V – 36 kV	Extended range; 33–35 kV distribution networks
HST-1.5N	AC 600 V – 7000 V; DC 600 V – 7000 V	FRP insulated stick; AC and DC installations
HSN-6A2	Up to AC 10.5 kV / DC 21 kV in withstand tests	Withstand voltage testing

The HSS-25B1 and HSS-36B1 allow checks from a distance by extending the stick; however, low voltage cannot be detected in extended mode. The HSE-7G responds at 3000 V on insulated conductors (φ5 mm OE cable); at lower voltages, contact with a bare conductor is required. The HSN-6A2 is recommended for use in withstand voltage tests rather than for general live/dead checks.

Points to note in use

• With hand-held models, the approach distance to the conductor is determined by the user's arm. Where a minimum approach distance must be maintained, hot-stick high-voltage detectors should be preferred.
• Before measuring, verify that the detector works with a voltage detector tester or a known live source, and wear insulating gloves suited to the MV class.

All voltage classes are compared on the voltage detectors page. The selection criteria are covered in detail in our article How to Choose a Voltage Detector.

Frequently Asked Questions

Which model from this category can be used in 36 kV-class switchgear?

The model covering 33 kV and 35 kV systems is the HSS-36B1, with a range of AC 80 V – 36 kV. The upper limit of the HSS-25B1 is 25 kV, so it is not suitable at this level.

Which model should be chosen for DC installations?

The model in this group that works on DC is the HST-1.5N, with a range of 600 V – 7000 V on both AC and DC.