American Power Conversion MatrixTM UPS - Manual (Page 17)

5.1.5 Bypass mode
When in the bypass mode of operation, the load is supplied power conditioned by the Isolation Unit. However, the load
will not be protected from utility voltage sags, swells or blackouts. The UPS will automatically transfer to bypass
operation when a failure occurs within the Electronics Unit. Detected EU failures include blocked fan, battery charger
fault, overtemperature and welded main relay; see section 7.2 for a complete list of fault messages. The UPS will also
automatically transfer to bypass if the EU separating screw is loosened (as if the EU were to be pulled off the IU). A
manual bypass switch located on the EU is used when maintenance of the EU is required. In all cases, the UPS must be
returned to on-line operation manually.
Local users are alerted to this mode of operation by visual and audible indicators. When in bypass, the UPS displays the
reason for bypass (fan failure, EU switch actuated, etc.) and "beeps". The UPS alerts remote users to the bypass
conditions via serial communications from the computer interface port.
5.1.6 Transfer between modes of operation
Transfer of load power to and from all modes of operation occurs synchronously with the utility voltage phase. See the
Specifications section of this manual for transfer time ratings.
5.2 Display and Controls Operation
The UPS is equipped with a 2x16 character back lit liquid crystal display (LCD) and three button keypad user interface.
The display is structured with five main menu screens and a default screen. Each main menu screen allows access to
several sub-menu screens. Using the pushbuttons, the user can scroll through the menus and access information or
control choices for UPS operation, status, diagnostics, set-up, and tests. The main menu and sub-menu selections are
described in the following sections.
5.2.1 Default screens
The UPS’s mode of operation is displayed by the default screen. Important fault messages
are also communicated by the default screen. The UPS will show the default screen and
the main menu screens when the Menu key is successively pressed. The UPS will
automatically show the default screen after there has been no keypad activity in the
previous 3 minutes or whenever warranted by a change in mode of operation or failure.
Examples of the most common default screens are shown at the left.
5.2.2 Main menu screens
The UPS will show the main menu screens when any default screen key is pressed or
when the Menu key is successively pressed. The five main menu screens are show in
order at the left.
The main menu screens allow access to screens that display operational choices or
show information on UPS status, diagnostics, set-up and tests. Access to the
sub-menu screens is gained by pressing the Scroll key. To return to the main
menu, press the Menu key.