FZW28-12(F) Branch Load Switch (Watchdog)

FZW28 Branch load switch is named as Watchdog.  If there is a fault occurs at the user side’s incoming line section, or fault occurs inside the user’s load side section and the user side protection active time setting does not cooperate with substation’s transformer protection time setting, the substation transformer line outgoing switch may automatically open. If the fault is permanent and automatic reclosing does not resolve the problem, therefore, a fault occurs at user’s side will cause the power down for the whole outgoing line from substation which is a part of power distribution network.

The user switch is the ideal equipment solving the accidents above. It’s installed in the duty point of 10kV overhead line, could automatically cut the single phase to earth fault and automatically isolate phase to phase short circuit fault to ensure the using safety of non-fault user.

Typical Function of Watchdog Switch

Auto-cut single phase to earth Fault   Automatically opening the switch, abandoning the faulty branch, the users of substation and other feeders will not impacted by the fault.

Auto-isolate phase to phase short circuit fault  When the substation outgoing cable protection automatically breaks due to short-circuit fault happens at branch of feeder line, the watchdog instantly switches off, abandoning the fault branch and then the substation protection recloses so the faults have been isolated that the feeder line’s users are having their power supply back.

Rapid Positioning Fault Point  The action of Watchdog caused by the fault of branches of feeder line only affecting theactual fault branch, and the fault is being automatically reported to power distribution company in order to pinpoint the exact fault location, and arrange for recovery.

Monitoring the user load   the Watchdog can detect and transmit the load data to power supply center to realize the real time load monitoring.