Vertiv™ | Liebert® STS2/PDU
™
User Manual | Rev. 6 | 10/2017 80
To return to normal mode:
1. Remove the key from CB5 and insert it in the CB1 breaker interlock.
2. Rotate key to retract interlock.
3. Close source input breaker CB1.
4. Verify the Source 1 and CB1 breaker status on the Mimic screen.
5. Select the SOURCE 1 button in the SOURCE XFERS menu.
6. Close output breakers CB3 and CB3A (if supplied).
7. Verify CB3 and CB3A breaker status on the Mimic screen.
8. Verify that STS SOURCE 1 and OUTPUT boxes are highlighted on the Mimic screen.
9. Open bypass breaker CB4.
10. Rotate the keys in CB4 interlock to extend the interlock.
11. Remove the proper key from CB4 interlock and insert it into CB2 breaker interlock.
12. Rotate the key to retract the CB2 breaker interlock.
13. Close source input breaker CB2.
14. Verify the STS SOURCE 2 box and CB2 breaker status on the Mimic screen.
• If the Color Graphical Display is not available, check the gate driver board LEDs through the slots in the control panel.
See Figure 60.
10.4.2 Bypass Procedures for Source 2
To bypass the switch for Source 2:
1. Verify Source 2 is supplying power via the Mimic.
• If the Color Graphical Display is not available, check the gate driver board LEDs through the slots in the control panel.
See Figure 60.
2. Remove the interlock key from CB4 and place it in CB5 interlock.
3. Open the alternate source input breaker CB1.
4. Rotate and remove the CB1 interlock key.
5. Insert the key in the CB5 bypass breaker interlock.
6. Rotate interlock keys in the CB5 bypass breaker interlock to retract the interlock.
7. Close bypass breaker CB5.
8. Verify the breaker status on the Mimic screen.
9. Open source input breaker CB2.
10. Rotate the interlock key and remove it to lockout the breaker.
11. Secure the key, per your site’s lockout/tagout procedure.
12. Open output breakers CB3 and CB3A (if supplied) to remove power and isolate the static switch from the load.
NOTE
If you wish to bypass the Source 2 static transfer switch but Source 1 is presently active, you must first
transfer to Source 2. See 10.2 - Manual Transfer / Preferred Source Selection.