20
4. OPERATING PROCEDURE
This section outlines the procedure to turn on and off your UPS and perform a transfer from UPS to
Bypass and vice-versa. All of the power controls are conveniently located on the front of the UPS. The
Main battery breaker controls the connection of the UPS to all batteries (internal or external). With this
breaker off, no battery power will reach the electronics of the UPS. The External Battery Breaker (only
present on systems with external battery cabinets) connects the external and internal batteries in
parallel. This breaker, along with the breaker in the external battery cabinets, must be ON in order for
the external batteries to be utilized by the UPS. The AC Input Breaker connects the UPS to the AC
utility, and it must be on for the UPS to derive its output power from the utility. All of these breakers
must be on for the system to operate correctly.
The large rotary switch, called the Transfer Switch, is used to control the operating mode of the UPS.
This switch has four positions. When in the OFF position, the UPS will not provide any output voltage
and the internal control circuits and power circuits are off. When in the OFF IDLE position, the UPS will
still not provide any output voltage, but all of the internal controls will operate while the internal power
circuits are energized but are not functioning. The ON UPS is the normal operating position for the
UPS. The UPS is fully operational when the switch is in this position. The load is protected and
powered by the UPS while in the ON UPS position. The ON BYPASS position is used to connect the
load directly to the AC utility. While in this position, the load is
not
protected or powered by the UPS. In
fact the breakers on the front of the UPS can all be turned off, including the AC Input breaker, without
affecting the operation of the load. However, should the switch be in this position when a utility failure
occurs, the load would crash. If the UPS breakers are left on while in this ON BYPASS position, the
UPS would continue to operate, but its output is disconnected from the load. This ON BYPASS position
is provided so that maintenance can be performed on the UPS without interrupting power to the load or
to allow the load to be powered directly from the utility should a failure occur in the UPS that prevents
the UPS from providing power to the load. When maintenance on the UPS is complete, the load can be
switched back from the AC utility to the UPS without interruption of power to the load.
The front panel LCD display and keypad are very powerful diagnostic tools that can be used by the
operator to detect problems both internal and external to the UPS. This 8 line by 40 character display,
informs the operator in English of all normal and abnormal conditions seen by the UPS. Should a
problem develop, the operator can quickly determine the cause using the information displayed. Many
problems are caused by faults outside the UPS such as overloads due to the load being too large or
not evenly distributed among the 3 output phases or due to a failure of a load. Also, AC line problems
caused by other equipment connected to the same utility feed pulling large inrush currents can occur.
The LCD display provides an abundant amount of information that allows the operator to detect and
correct such external problems without the need of a more costly service call. Internal UPS problems
are also more easily diagnosed and are, therefore, corrected much faster.
Besides providing the usual voltages, currents, etc., as well as very comprehensive diagnostic displays,
your UPS has what is referred to as historical data storage. Historical data storage allows abnormal
events such as AC line problems, overloads, and abnormal shutdowns to be saved in battery backed-
up memory which keeps the data intact even when the UPS is shut off. The operator can look at this
historical data either immediately, or at a later time, to determine exactly what problem the UPS
encountered. This information can be invaluable in detecting one-time or sporadic problems with the
load, AC line or UPS.
4.1 SYSTEM TURN-ON
Normally, the UPS can be switched on by simply turning on the main battery breaker and AC input
breaker on the front of the UPS, and turning the rotary "transfer switch" clockwise from the OFF
position to the OFF IDLE position and then to the ON UPS position (there is no need to stop at the OFF