Interlocking relay (PBL) is designed for permanent and safe control of voltage presence on busbars in medium voltage switchgear. Voltage control prevents accidental earthing of the busbar. The relay is suited for operating with insulators equipped with capacitive or resistive dividers.
The ralay can supply the coin, which blocks the connection of the earthing with the current, preventing the closing of the earthing switch in the presence of voltage at its terminals.
The relay continuously measures the currents in the circuits of the three inputs (L1-N1, L2, N2, N3, L3) connected to the output of the measuring insulators. Switching relay: authorization is only in the absence of currents in the input circuits (currents below the threshold) and after pushing the ‘odblokowanie button’ for about 30 sec. Input circuit clamps are located on the rear panel. For proper operation of the relay you need auxiliary power supply to be connected to the clamps on the rear panel (L +, N-).
The front panel includes banana type jacks connected directly to the input clamps on the rear panel. Next to the slots there are signals, indicating the presence of current in the circuit inputs. On the left side the front panel, there are two control signals – red - no authorization signaling the flow of current in the circuit inputs and green - the authorization - signaling the lack of current flow.
In the presence of voltage on the lines (L1-3) contacts are in a “no authorization” (compact P2-P3 and P4-P5, the relay in idle mode). In the absence voltage on the lines of contacts go into a state of “authorization” (shorted contacts P1-P2 and P4-P5, the relay energized) for about 30 sec. The button ‘odblokowanie’ is highlighted.
All technical data presented in the catalog can be changed due to technological progress.