7SR210 & 7SR220 Description of Operation
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Trip Time Alarm
The CB Trip Time meter displays the measured time between the trip being issued and the CB auxiliary contacts
changing state. If this measured time exceeds the Trip Time Alarm time, a Trip Time Alarm output is issued.
Trip Time Adjust
This allows for the internal delays caused by the relay – especially the delay before a binary input operates – to
be subtracted from the measured CB trip time. This gives a more accurate measurement of the time it took for the
CB to actually trip.
Hot Line In/Out
The Hot Line function can be used to provide an immediate trip and auto-reclose inhibit for any Overcurrent, Earth
Fault or Sensitive Earth Fault detection. This function is used to increase safety when personnel are working in
the vicinity of live primary equipment.
When Hot Line is enabled, pickup of any 50, 51, 50G, 51G, 50SEF or 51SEF element will cause an instantaneous
trip, bypassing any time delay setting of the element. Any auto-reclose sequence will be inhibited and Auto-
reclose Lockout will be raised. This feature is not triggered by pick-up or operation of other protection elements
such as under/over voltage, frequency, thermal or negative sequence over-current.
Additionally, when Hot Line is In, Manual Close is inhibited. This can help to prevent unintended energisation of a
dead circuit whilst personnel are working nearby. Hot Line must be switched to Out before the Manual Close
action will be successful.
Hot Line can be configured to be switched In/Out by binary inputs, function keys or by commands via the
communications protocols. There are no other configurable options for Hot Line.
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