System Testing; Local Test; Remote Test - ABB OTM C 21D Installation And Operating Instructions Manual

3.3 System testing

3.3.1 Local test

In automatic mode, "AUTO" LED is ON and you can transfer the switch using I, O, and II push
buttons on the front panel of the switch.
Press "AUTO" button to return the automatic operation.

3.3.2 Remote test

The procedure of the remote test is as follows:
1. Connect to the remote test signal according to Figure 7.
2. Ensure that the OTM_C_21D is in automatic mode ("AUTO" LED is on).
3. Short circuit the remote test signal for at least 100 ms until the "AUTO" LED blinks to enter the
test mode.
Under test mode, the automatic transfer switch will simulate switching cycle and finally return
to its original position prior to the activation of the test mode.
e.g., when the switch is in Position I:
Enter test signals; the switch transfers to Position O à to Position II à to Position O à to
Position I. Entering test signals is invalid before the automatic transfer switch returns to its
original position.
Under test mode, press the "AUTO" button to cancel test mode and return to automatic
mode. The "Auto" LED will be "ON" as normal.
4. After the remote test finishes, the OTM_C_21D automatically returns to the automatic
mode ("AUTO" LED is on).
In the test sequence, the main power supply circuit will be closed.
If the test sequence is interrupted due to power failure, the automatic
transfer switch will enter "automatic mode" after power recovery.
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1SCC303015M0201 l ABB Installation and operating instructions, 34OTM_C_21D rev. B
Figure 7. Remote test connection in OTM_C_21D
3. Description