Voltect Non-Contact Voltage Indicator

HASEGAWA Voltect is a non-contact voltage indicating and warning device that detects the presence of line voltage in substations, on transmission lines and in consumer installations without touching the conductor. It works on 50/60 Hz line voltages from 3.3 kV to 550 kV, covering everything from distribution feeders to extra-high-voltage switchyards. Its key advantage is that it needs no voltage transformer (VT/PT) or capacitive potential divider (PD) to obtain the voltage information, which makes installation economical and straightforward.

Voltect is manufactured by HASEGAWA, which took over the former Million Electric Mfg. technologies. HASEGAWA Türkiye, the official distributor in Türkiye, supplies the genuine HASEGAWA system on a project basis.

How does a non-contact voltage indicator work?

The device detects without contact whether the monitored line is energised and reports the result through the controller in three ways. The operation indicator lamp is red while the line is live and green when it is de-energised; it stays unlit (milky white) if the controller has no supply. In addition, a relay contact and a 0 – 1 mA DC meter output are provided.

The contact changes state within 0.5 s or less after the line is energised or de-energised (with the operating point setting ratio at 70 % or below). Single-phase types have a 1c contact and two-phase types 1c × 2 contacts; at 100 V DC they can switch 0.5 A resistive or 0.1 A inductive load. These outputs can be connected to alarm circuits, remote monitoring systems or panel indicators.

Choosing the controller

• Voltage-switching indicator (SM series): Provides live / dead information. Single-phase options are SM1AH (high sensitivity) and SM1A (standard); two-phase options are SM2AH and SM2A. A low-sensitivity SM (L) type is also available.
• Voltage-proportional indicator (DM series): DM1A (single-phase) and DM2A (two-phase) give a voltage-proportional output at standard sensitivity. The meter internal resistance is approx. 1.5 kΩ; on SM types it is below 5 kΩ.

Technical specifications

• Line voltage: 3.3 kV – 550 kV, 50/60 Hz
• Contact: response 0.5 s or less; maximum circuit voltage 180 V DC, 140 V AC
• Meter output: 0 – 1 mA DC
• Supply: 110 V DC standard (24 V and 220 V options); 75 mA single-phase, 100 mA two-phase
• Withstand: AC 2 kV, 1 minute; insulation resistance 10 MΩ or more at 500 V DC
• Impulse withstand: ±7 kV, 1.2 × 50 µs

Limits of use and safety

Voltect is an indicator for continuous monitoring and warning; it does not replace the verification of absence of voltage required before work on the line. Before work, test with a hot stick high voltage detector of the appropriate class and earth the line. For the difference between contact and non-contact methods, see our comparison article.

In circuits connected to the contact output, do not exceed the 180 V DC / 140 V AC limit or the stated switching capacity. Select the controller supply voltage to match the site's auxiliary supply, and have installation and commissioning carried out by authorised personnel.

Why buy from HASEGAWA Türkiye?

• We work out the mix of single- or two-phase, SM or DM controllers with you based on your number of feeders and panels
• We confirm the 24 V, 110 V or 220 V DC auxiliary supply option for your site at the ordering stage
• Multi-point project quotations with commercial invoice for substation and switchyard projects