Toshiba 431A operation manual MBS Operation, MBS Mechanical Interlock Plate Operation

13.8MBS Operation

Switch MBS from on-line to Bypass (Solid lines)

The 431M Mechanical Interlock Plate is locked in the On-Line position by a solenoid. When the UPS is placed in Static Bypass mode, the light on the front of the MBS lights and the interlock solenoid retracts and allows the Mechanical Interlock Plate to be moved. See Figure 13-8.

1.Place the UPS in static bypass. The Bypass indicator light on the 431M should illuminate and the interlock solenoid will retract.

NOTE: If the Bypass indicator light DOES NOT ILLUMINATE in bypass mode, contact Toshiba Field Service immediately.

2.Slide the Mechanical Interlock Plate to the center position as shown in Figure 13-8 B.

3.Switch CB2 ON (up) as shown in Figure 13-8 C.

4.Switch CB3 OFF (down) and CB1 OFF (down), as shown in Figure 13-8 D.

5.Slide the mechanical Interlock Plate to the left position as shown in Figure 13-8 E.

6.The circuit breakers are now locked in Maintenance Bypass position.

CB1

CB2

CB3

(A)	(B)
	CB3

(C)	(D)	(E)
On-Line to Maintenance Bypass

Maintenance Bypass to On-Line

Figure 13-8 - MBS Mechanical Interlock Plate Operation

Switch MBS from Bypass to On-Line (Dotted lines)

1.The Maintenance Bypass position is shown in Figure 13-8 E. The UPS should be in static bypass mode, and the MBS indicator light should be illuminated.

2.Slide the mechanical Interlock Plate right to the Center position as shown in Figure 13-8 D.

3.Switch in order, CB1 ON (up), and CB3 ON (up) as shown in Figure 13-8 C.

4.Switch CB2 OFF (down), as shown in Figure 13-8 B.

5.Slide the mechanical Interlock Plate to the right position as shown in Figure 13-8 A.

6.Place the UPS in On-Line mode.

7.The MBS indicator light should extinguish, and the MBS solenoid locks the Mechanical Interlock Plate in place.

4300 Series Ancillary Cabinets Installation and Operation Manual 59