INSTALLATION (continued)

Functional Test (continued)

2 – Voltage Checks

First check nameplate on the transfer switch for rated voltage. It should be the same as the normal and emergency line voltages.

Use extreme caution when using a meter to measure voltages in the following steps. Do not touch power terminals; shock, burns, or death could result !

1.Close the normal source circuit breaker. The Load Connected To Normal lamp should come on.

2.Use an accurate voltmeter to check phase to phase and phase to neutral voltages present at the Transfer Switch normal source terminals.

3.Close the emergency source circuit breaker. (Start the generator, if necessary.)

4.Use an accurate voltmeter to check phase to phase and phase to neutral voltages present at the Transfer Switch emergency source terminals.

If necessary, adjust the voltage regulator on the genera- tor according to the manufacturer’s recommendations. The ASCO 386 will respond only to the rated voltage specified on the Transfer Switch nameplate.

5.Check phase rotation; it must be the same as the normal source.

6.Shut down engine-driven generator, if applicable.

7.Close the cabinet door and tighten the screws.

3 – Electrical Operation

This procedure will check the electrical operation of the Non-Automatic Transfer Switch. See Figure 1–3.

Close the transfer switch enclosure door and tighten the screws before you test electrical operation.

Transfer Test

Both normal and emergency sources must be available and above 90% of nominal voltage specified on name- plate.

1.Turn the door-mounted Transfer Control switch clockwise to Transfer To Emergency.

2.The transfer switch will operate to the Emergency position. The Load Connected To Emergency light should come on and the Load Connected To Normal light should go off.

3.Turn the door-mounted Transfer Control switch counterclockwise to Transfer To Normal.

4.The transfer switch will operate back to the Normal position. The Load Connected to Normal light should come on and the Load Connected To Emergency light should go off.

This completes the Functional Test of the ASCO 386 non-automatic transfer switch.

Figure 1–3. Operating Controls.

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Emerson 381333230 manual Voltage Checks, Electrical Operation