P-164000249 30-200 kW 19Revision 2 User's and Installation Guide2.5 Options and accessoriesContact an Eaton sales representative for information about the available options.2.5.1 Maintenance Bypass SwitchThe Maintenance Bypass Switch (MBS) enables power to completely bypass and isolate the UPS sothat the UPS can be safely serviced or replaced without interrupting power to critical systems.An internal maintenance bypass switch is provided as a factory installed option for 30-150 kW units.Alternatively, MBS solutions are also available in external enclosure as accessory items.External Maintenance Bypass Switch PanelThe external MBS is enclosed in its own separate cabinet, and it can be either a wall-mounted orstand-alone cabinet depending on the MBS power rating. The MBS wiring has two different options:two- and three-switch configuration. The two-switch model contains a Maintenance Isolation Switch(MIS) and a Maintenance Bypass Switch (MBP). The three-switch model contains a Bypass InputBreaker (BIB) in addition to a MIS and an MBP.The two-switch model assumes that the UPS rectifier and bypass are coupled through dedicatedbreakers and separate cables from the switchgear. However, the three-breaker model can beconnected to the switchgear with only a single cable, and the cable connections between the paneland UPS are run separately.For more information, see Figure 2-8: Two-switch MBS electrical connection drawing on page 20and Figure 2-9: Three-switch MBS electrical connection drawing on page 21.
