1.2.2.2 Time Dial
A numerical value normally associated with a TIME CURVE, or defines the use of a specific time
curve from a family of curves. Used when conducting a timing test. The TIME DIAL number also
may be used in a Time-Curve algorithm in calculating the theoretical operating time of the relay
under test.
1.2.2.3 Instantaneous (Inst.) Tap
A numerical value associated with a tap setting on the instantaneous element of the relay.
Normally associated with a value of current or voltage. Used to define a pick up value, or
minimum operating point, of the instantaneous element of the relay under test.
1.2.2.4 Reset Time
Is a numerical value of time in seconds. Normally associated with electromechanical relays, this
is the amount of time required for the operating disk to reset. If multiple timing tests are
conducted on a relay, the test system will wait the Reset Time value prior to applying the next
timing test.
Note, if the Reset Time is too short, and the disk does not completely reset, then timing error
will be introduced to the test. Note that numerical relays also can have reset times to coordinate
with electromechanical relays.
1.2.2.5 Target Tap
Is a numerical value of dc current. This value is used when conducting the Target and Seal-in
tests on electromechanical relays.
1.2.2.6 Test Multiple
A numerical value normally associated with conducting timing tests. Multiples are normally
expressed in terms of 2, 3, 4, etc., times the Relay Tap, or Pickup, value of the relay under test.
If only one Test Multiple is entered, then only one timing test point will be conducted. If two or
three multiples are entered, then the test system will wait the Reset Time before applying the next
Test Multiple.
1.2.2.7 Reach
A numerical value expressed in Ohms. This value is used to determine the “distance”, in Ohms,
that the relay under test “sees” either into the transmission line or a generator.
1.2.2.8 Torque
A numerical value expressed in degrees. A value used in impedance relays to define the
“maximum torque angle” or “line angle” setting of the relay under test.
1.2.2.9 Operate, (Op) or Trip Time
A numerical value which expresses the operating time of the relay under test. Normally used to
specify a definite operating time for a given fault value.
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