Vertiv Liebert STS2/PDU - Page 112

Vertiv™ | Liebert
®
STS2
™
100-1000A, 50/60Hz User Manual | Rev. 12 | 11/2017 104
To return to normal mode:
1. Verify that the LED for Source 1 is On, indicating that the source is supplying power and is operating within acceptable
tolerances.
2. Insert the key in the CB1 breaker interlock.
3. Rotate the key to retract the interlock.
4. Close source input breaker CB1.
Verify that CB1 LED is On.
5. Select the SOURCE 1 button.
6. Close output breakers CB3 and CB3A (if supplied).
Verify that CB3 and CB3A LED’s are On.
7. Verify that STS SOURCE 1 and OUTPUT LED’s are On.
8. Open bypass breaker CB4.
Verify that CB4 LED is Off.
9. Rotate the keys in the CB4 interlock to extend the interlock.
10. Remove the proper key from the CB4 interlock and insert it in the CB2 breaker interlock.
11. Rotate the key to retract the CB2 breaker interlock.
12. Close source input breaker CB2.
Verify that CB2 LED is On.
Bypass Procedures for Source 2
To bypass the switch for Source 2:
1. Verify that Source 2 is supplying power via the LED display.
• If the LED Display is not available, check the gate driver board LED’s through the slots in the control panel. See
Figure 43.
2. Remove the interlock key from CB4 and place it in the CB5 interlock.
3. Open the alternate source input breaker CB1.
Verify that CB1 LED is Off.
4. Rotate and remove the CB1 interlock key.
5. Insert the key in the CB5 bypass breaker interlock.
6. Rotate the interlock keys in the CB5 bypass breaker interlock to retract the interlock.
7. Close bypass breaker CB5.
Verify that CB5 LED is On.
8. Open source input breaker CB2.
Verify that CB2 LED is Off.
9. Rotate the CB2 interlock key and remove it to lock out the breaker.
10. Secure the key according to your site’s lockout/tagout procedure.
11. Open output breakers CB3 and CB3A (if supplied) to remove power and isolate the static switch from the load.
Verify that CB3 and CB3A LED’s (if supplied) are Off.
12. Verify that the output LED is On.
Power is now flowing directly from the source to the load, without passing through the static transfer switch.
NOTE
To bypass the Source 2 static transfer switch when Source 1 is presently active, you must first transfer to Source
2. See 14.2.2 - Manual Transfer / Preferred Source Selection.