Monitoring relay VRBU3, VRBU3N

• This unit monitors a 3-phase supply for phase imbalance, low or missing phases or
incorrect phase sequence and trips a relay if it detects any anomaly. A front panel control allows selection of minimum voltage level. LEDs indicate power on and trip status.
• Versions are available to suit 3-wire, 3ph (VRBU3) and 4-wire, 3ph+N (VRBU3N) supplies of 110 V, 210 V and 430 V nominal. The 110 V and 120 V versions occupy a single
module width on the DIN rail and have a single relay contact whereas the 430 V version occupies a three-module width and has two relay contacts.
• These instructions contain important safety information. Please read them thoroughly before commissioning, operating or maintenance of the unit.