24
pressed, the display will indicate a UPS to BYPASS transfer has been requested. If the AC utility is not
present at the time, the UPS will not allow such a transfer to take place, as doing so would switch the
critical load to a non-existent utility, which would crash the critical load. If all conditions are OK for a
transfer to take place, the LCD display will indicate so and ask you to press the key to proceed. After
a few seconds after pressing the key, the LCD will instruct you to turn the transfer switch. You have
a limited time to turn the switch (the LCD display will tell you how much time). If you fail to turn the
switch in the designated time, the operation will be aborted and you will have to start the procedure
over. Note that it is normal for the Battery Discharging front panel light to come on after you press the
key and for the audible alarm to start beeping after 10 seconds. If you decide to continue with the
transfer to ON BYPASS, the switch should be promptly turned to the ON BYPASS position. Once you
turn the transfer switch, the UPS will issue a warning to tell you that you are in the Bypass mode of
operation, which means your load is not protected from power outages on the AC line.
When you wish to go back from the ON BYPASS position to the ON UPS position, use this same
procedure. The only difference is that the UPS will display that you are attempting to transfer from
BYPASS to UPS and that you will be turning the switch counter-clockwise to the ON UPS position.
When performing a transfer between UPS and BYPASS or vice-versa make sure that you do not
accidentally turn the switch in the wrong direction or turn the switch too far so as to enter the OFF or
OFF IDLE positions. Doing so will cause the output from the UPS to shut off and your load to crash.
The UPS must disconnect itself from the AC line and operate from batteries during a transfer. To
conserve battery energy, promptly turn the switch as soon as possible after the LCD screen instructs
you to turn the switch. DO NOT attempt subsequent transfers if the LCD screen says that a transfer is
not possible due to low or bad batteries. If the LCD screen indicates a transfer is not possible you may
perform an interrupted transfer. Such a transfer will result in an interruption of voltage to the load;
therefore, all critical loads should be shut down in an orderly manner before attempting an interrupted
transfer. An interrupted transfer from ON UPS to ON BYPASS is accomplished by turning the transfer
switch counter-clockwise to the OFF IDLE position, then to the OFF position, and then to the ON
BYPASS position. An interrupted transfer from ON BYPASS to ON UPS is accomplished by turning the
transfer switch clockwise from ON BYPASS to OFF to OFF IDLE and ON UPS positions. REMEMBER:
DO NOT ATTEMPT AN
INTERRUPTED
TRANSFER UNLESS ALL CRITICAL LOADS ATTACHED TO
THE UPS ARE ALREADY POWERED DOWN!
If the Transfer switch is in the ON UPS position, but the UPS is not producing an output to the load
because of a fault condition, you will not be able to turn the switch clockwise to the ON BYPASS
position. The only way to change to the ON BYPASS position when the UPS is not producing an output
is to turn the switch counter-clockwise from ON UPS to OFF IDLE, to OFF, and finally to ON BYPASS.
4.3 SYSTEM TURN-OFF
Before you turn off your UPS, make sure that all critical loads are prepared for the loss of power. When
you have confirmed this, turn the rotary transfer switch counter-clockwise to the OFF IDLE position and
then to the OFF position. The UPS will immediately stop producing an output and a solid audible alarm
will be produced to indicate the UPS has been shut down once the switch leaves the ON UPS position.
Also, the LCD display will indicate a shutdown has occurred because of the transfer switch being
switched to the OFF IDLE position. Once the transfer switch reaches the OFF position, the UPS
controls will also shut down in about 5 to 10 seconds. You may also turn off the breakers on the front of
the UPS, but this is unnecessary unless you plan to open the unit. If left in the OFF IDLE position, the
controls of the UPS will continue to operate for about 2 hours (but the UPS power output will be off). At
the end of this 2 hour period, the UPS will turn itself completely off by tripping the Main Battery and AC
Input breakers automatically.
