Eaton Ferrups FX UPS P-164000906 Eaton Ferrups FX User’s Guide P-164000906—Rev 05
13
To reduce the possibility of electric shock all AC and DC terminal covers must be installed on the back of the
UPS prior to applying power to the Eaton Ferrups FX series UPS.
44..44
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If your UPS does not have a plug, a bypass switch can transfer the protected equipment to direct AC input
power conveniently when it is time to service the UPS.
BPE bypass switches are available in two types MBB ( Make Before Break ) and BBM ( Break Before Make )
A MBB switch makes a new connection before it breaks the original connection. For example, if you turn an
MBB switch from UPS to LINE, the bypass switch connects the load to AC input power before disconnecting
the load from UPS output power.
A BBM switch breaks the original connection before it makes a new one. If you turn a BBM switch from UPS to
LINE, the switch disconnects the load from UPS output power before connecting the load to AC input power.
Table 6. BPE Bypass Switch Positions
Switch Position Description
Line
Connects the load directly to AC input power and disconnects
UPS output. AC input power is still connected to the UPS input.
Off
Disconnects the load from the UPS output power and AC input
power.
UPS
Connects the UPS output to the load.
NOTE
In all three positions, AC input power is still connected to the input terminals inside the
UPS (once the UPS is installed). Use the AC disconnect switch (located on the right side
of the bypass switch) to disconnect AC input power during maintenance or service.
Do not attempt to change the BPE bypass switch position if the UPS is operating on battery power. This can
cause damage to the bypass switch or the UPS.
