Dvb01 User Manual Upd «95% Fresh»

Capable of monitoring DC voltages typically from 0V to 100V (actual range depends on configuration). Relay Output Capacity: DC: 0V–30V / 10A. AC: 0V–250V / 10A. Operating Modes (P-1 to P-5)

Positive terminal of the voltage being measured (Source). dvb01 user manual

The relay pulls in when the measured voltage is between set limits and releases when outside them. Capable of monitoring DC voltages typically from 0V