Date Code 20010719 701 Motor Protection Relay
Commissioning
Selected Functional Tests
7.13
Step 3. Set the current source phase angles to apply balanced three-phase
currents. Refer to Figure 7.1 on page 7.4 for the correct angles that
depend on the PHROT setting.
Step 4. Turn on the current sources and increase the current applied to the
relay. Refer to Tab le 7. 5 to determine the appropriate magnitude for
each phase current. Use the front-panel Meter Values\Instantaneous
Meter function to view the unbalance current measurement
(U/B = xx%). For each applied current value shown in Table 7.5, the
relay should display unbalance current magnitude equal to the
expected reading percent shown.
Table 7.5 Curr ent Unbalance M easuring Acc uracy
Motor Thermal Element Accuracy
NOTE: This test outlines steps to verify performance of any of
the GENERIC thermal curves. When using the RATING or USER
thermal element setting methods, the steps are similar, but
the expected operating times will be different, depending on
the settings you use.
Step 1. Connect the current sources to the IA, IB, and IC current inputs
(5 A or 1 A, as indicated by the ITAP setting).
Step 2. Using the front-panel Set Relay\Relay Elements\Thermal Model
Elements function or serial port SHOW command, note the PHROT,
FLA, and CURVE settings. Set the Service Factor setting, SF equal
to 1.15.
Table 7.5 Current Unbalance Measuring Accuracy
|I| Applied (A secondary) Expected Reading (%) Actual Reading (%)
|IA| = 0.9 • FLA
|IB| = FLA
|IC| = FLA
7%
|IA| = 0.75 • FLA
|IB| = FLA
|IC| = FLA
17%
|IA| = FLA
|IB| = 1.2 • FLA
|IC| = 1.2 • FLA
12%
|IA| = 0.9 • FLA
|IB| = 1.1 • FLA
|IC| = 1.1 • FLA
13%
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