ZIV 7IRD-A - Manual and External Blocking

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Chapter 6. Description of Operation of Protection Subsystem

M7IRDA2003I

7IRD-A/J/M: Distribution Protection & Control Terminal

6-18

 Recloser Manual Close

If the Recloser Manual Close Enable setting is YES in the Logic Settings, then reclosing is

initiated when the Recloser receives a Manual Close Command signal from a Status Contact

Input. The subsequent closing sequence is similar to a final programmed reclose attempt except

there is no Sequence Check Time. Also, the following Reclose Sequence settings supersede

those associated with a final programmed reclose attempt:

- Manual Close Supervision By Reference Voltage (equivalent to Supervision of the

Reference Voltage Reclosing setting).

- Time Delay on Reference Voltage.

- Time Delay on Inhibit Input Deactivation.

- Time Delay on Manual Close (equivalent to Reclosing Time).

- Reset Time after Manual Close.

Near the end of the Recloser Manual Close sequence, at breaker closure, the Reset Time

after Manual Close timer is started. Recloser Lockout results if a mask enabled trip output

occurs during this period of time. If no trip occurs, the Recloser returns to the Recloser Reset

state.

6.6.4 Manual and External Blocking

There are two types of block signals, Manual and External. Priority is given to the block

commands received first. To remove the block the corresponding opposite command should be

issued.

 Manual Blocking

The Recloser can be manually blocked with the Recloser Block command via the operator

interface keyboard on the terminal unit. If the Recloser is in a Reclose Sequence when the

Block Reclosing command is received, further operations are suspended. No reclose attempts

are initiated after a breaker trip.

A Recloser Unblock command must be entered from the operator interface to exit the Blocked

status. If the breaker is open when this command is received, the Recloser changes to the

Recloser Lockout state. If the breaker is closed when the Unblock command is received, the

Reset Time after Manual Close timer is started.

 External Blocking

The Recloser External Lockout feature operates the same as Block Reclosing, except that

commands are executed through Status Contact Inputs instead of the operator interface.

The Recloser External Lockout state can be controlled by the status of one single status

contact input or by two separate contact inputs, depending on the model.

Block Reclosing commands override Recloser External Lockout commands. If the Recloser

receives a Recloser Block command while in the Recloser External Lockout state, the

Recloser changes to the Recloser Blocked state which can only be reset by a Recloser

Unblock command.