Toshiba GRL100-701B Instruction Manual page 227

The fourth line (Open2) is displayed only for three-terminal line application ("3TERM" setting).
The automatic monitor function (A.M.F.) can be disabled by setting the switch [A.M.F] to
"OFF".
A.M.F.
Disabling the A.M.F. prevents tripping from being blocked even in the event of a failure in the
items being monitored by this function. It also prevents failures from being displayed on the
"ALARM" LED and LCD described in Section 4.2.1. No events related to A.M.F. are recorded,
either.
Disabling A.M.F. is useful for blocking the output of unnecessary alarms during testing.
Note : If the simulated fault inputs are applied under a failure condition and the A.M.F. is switched
"OFF", the relay will issue a trip command but the operation of the relay cannot be displayed
correctly.
L.TEST
The switch [L. test] is used for local testing.
When the switch [L. test] is set to "1" (=On), the voltage and current data received from the
remote terminal are set to zero. This switching is transmitted to the remote terminal and the
remote terminal sets the voltage and current data received from the switching terminal to zero.
Thus in the three-terminal application, the out-of-service terminal can carry out a local relay
testing without disturbing the in-service terminals.
Note : When [L. test] is set to "1" (=On) in the two-terminal application, the current differential
element can operate at both terminals if the load current is larger than the setting of DIFI1.
Open1, Open2
The switch [Open 1] and [Open 2] are used to maintain two terminal operation in three-terminal
line application, when one terminal is out-of-service (i.e., breaker and/or disconnector are
opened) due to relay failures or communication failures and fault investigations.
When the remote terminal 1 or 2 is out-of-service, set the switch [Open 1] or [Open 2] to "1"
(=On) at the in-service terminals to remove the out-of-service remote terminal from protection.
The remote terminal 1 is a terminal to which the local communication port 1 is linked and the
remote terminal 2 is a terminal to that the local communication port 2 is linked.
T.TEST
The switch [T. test] is used for local testing of the current differential elements. When the [T.
test] is set to "1" (=On), the local current data is looped into the receiving circuit interrupting the
current data from the remote terminal as well as transmitted to the remote terminal.
Note : The switch [T. test] must be used only when all the terminals are out-of-service. If not, the
local test current may cause a disturbance at the in-service remote terminal because this
switching is not recognized at the remote terminal.
In case of electrical interface, the electrical cable must be removed to prevent signal
interfering between sending and the receiving data. The remote terminal will detect the
communication failure.
D.TEST
The switch [D. test] is used to test the relay models with an optical interface (Short wavelength
light, GI, 2km class) and with an electrical interface in accordance with CCITT-G703-1.2.1,
1.2.2 and 1.2.3. Setting the [D. test] to "1" (=On) enables loop-back tests as well as end-to-end
tests of the relays under the direct connection of the communication circuit. For the loop-back
test or end-to-end test setup, see Section 6.5.1.1.
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