Voltage detectors for urban public transportation (trolleybus / tramway) – DTTU type



DTTu-Tb and DTTU-Tv voltage detectors for urban transport power installations (trolleybus /tramway), with d.c. voltage of 825 V are warning equipment for the maintenance and operating personnel on the existence of the electric shock hazard, by the optical and acoustic indication of voltage presence.
The optical warning is made with intermittent red signals (for reversed polarity) or green (for normal polarity), also visible in strong ambient lighting conditions.
Acoustic warning is triggered by intermittent signals with an intensity of 69 dB (A).

Both before and after each use, by pushing the test button and the triggering of signals, there will be verified the detector`s functionality (confirming that the battery is in good condition and the electronic circuits are in proper condition).

DTTU-Tb and DTTU-Tv voltage detectors must be used in dry weather conditions.

The DTTU-Tb detector for trolleybus includes two insulating sticks (which include detection components) which allow the detection of voltage presence on the two power contact lines of trolleybuses. This type of detector can also be used in switch boxes (power injection points) and in power distribution stations.

The DTTU-Tv detector for tramway includes an insulating stick (which includes the detection components) which is connected, by means of an 8-meter insulated earthing cable, to an alligator clip which can be attached to the rolling track (rail).
The checking of voltage can be performed from remote, using an appropriate insulating stick + an appropriate adaptor (e.g. telescopic stick PTU-AS-400-4c + adaptor AC-DTTU or modulated stick PMU 400-3 B/ba + adaptor AB-DTTU).

Technical characteristics


Maximum operating voltage (V d.c.)


Intermittent signalling, optical and acoustic, in bipolar connection for voltage rates higher than (V d.c.)

130 ± 20

Dielectric test voltage (V/1min)



9 V battery type 6LR61

Operating temperature range (0C)

-25 …+55

Protection class provided by the housing

IP 20

Weight DTTU Tb / DTTU Tv (kg)

1,35 / 1,19

Voltage detector stick length (cm) 67