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frequency shift will cause the "AC Fault" light to turn yellow and a blown fuse or tripped circuit
breaker will cause the fuse/breaker light to illuminate (RED).
The audible alarm can be silenced in both the "Normal Inverter" and the "Low Battery Warning"
modes by depressing the "Test/Alarm Silencer Switch" toward the "Alarm Silencer" position. The
alarm will automatically reset upon return to the "AC Normal" mode, providing an audible
indication of the next power problem. For long duration power outages or problems, the unit will
provide a low battery warning a minimum of two (2) minutes prior to low battery shutdown. At low
battery warning the "Battery Status" light will turn yellow and the audible alarm will turn back on, if
silenced previously. The alarm speed at low battery warning is more rapid -- four (4) times per
second.
If you have not already saved your data and turned off your critical loads, you must do so at this
time. The UPS will shut off automatically to protect the internal batteries form excessive
discharge. However, to conserve battery power you can turn off the UPS power switch after your
data is saved and loads are ready to be turned off. When commercial power is restored, switch
the MINUTEMAN power switch back on if it was turned off previously. The "AC Normal" LED will
come on after a short delay. Return your system to operations and the MINUTEMAN System will
automatically recharge the internal batteries during system operation.
Since most commercial power outages are of short duration, commercial power will probably be
restored before the low battery warning. IF COMMERCIAL POWER RETURNS BEFORE THE
WARNING SIGNAL, THERE IS NO NEED TO SHUT DOWN YOUR SYSTEM AT ALL. The
MINUTEMAN will switch back to normal AC mode operation automatically.
During normal AC mode operation, the MINUTEMAN unit will quietly protect your system form
power surges, voltage spikes and noise interference. No alarms will sound and the "AC Normal"
indicator light will remain "ON'" during this operation.
SYSTEM BATTERIES
The batteries used internally in AT Series MINUTEMAN units are sealed, maintenance free, lead-
acid batteries with electrolyte totally absorbed in the plates and separator material. These
batteries can be used in any position, except upside down. For maximum battery life, batteries
should be maintained at as cool a temperature as is practical indoors at proper trickle charge
voltage. The most effective charging temperature range is 41ºF to 95ºF. However, batteries can
be charged within the range of 32ºF to 104ºF (0ºC to 40ºC) without any detrimental effects.
Expected float life of the batteries is 3 to 6 years at 85ºF. We recommend replacement after 3
years of use. Replacement batteries can be purchased from Para Systems, Inc. or from your
local distributor or dealer. If the UPS must be stored, leave it plugged in with commercial power
applied and the power switch on for 24 hours prior to storage. Store the unit in a cool dry
location. For extended storage the unit must be removed from storage and recharged as above
every 4 months.
If batteries require replacement, refer to the "Important Safety Instructions" section on page 1 of
this manual. A trained service technician who is familiar with batteries and UPS systems must
accomplish replacement. Used batteries should be provided to a recycling center for reclamation
of the lead.
