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7
Features and operating limits
7th1
Mains limits for normal operation
Frequency and rms value of the mains input voltage has to be between acceptable limits for the UPS to
operate in normal mode.
Lower limit of the voltage depends on how much the UPS is loaded and it decreases as the load decreases
until it reaches 80 V phase-neutral.
Frequency lower and upper limits and voltage upper limit are fixed.
Voltage and frequency ranges for normal operation are given in the “technical specifications” section of
the manual.
This feature lessens the need to use the batteries. Thus, it increases the battery life and continuity of the
load power.
7th2
By-pass mains limits for bypass operation
Frequency, rms value and total harmonic distortion of the bypass mains input voltage has to be between
acceptable limits for the UPS to operate in bypass mode.
Different rms voltage upper and lower limits are present for the return from another operation mode to
bypass mode. This provides hysteresis and ensures that the device does not change operation mode very
often when the bypass mains rms voltage is close to one of the limits.
Bypass mains limits are software parameters. They can be changed upon request.
7th3
Battery test
This feature enables the user to obtain information about the battery condition. If the batteries have
approached end of their lives, batteries fail.
Battery life depends on several parameters like the number of charge-discharge cycles, discharge depth
and ambient temperature. Battery life greatly decreases as the ambient temperature increases. Therefore it
is recommended to keep the ambient temperature about 20 °C.
To perform a battery test, enter “START B. TEST” in the COMMANDS menu and wait. The UPS will
switch into battery mode, when the test has started. After about ten seconds, UPS will return to the
operation mode before the test. If the batteries pass the test, no alarm will be shown.
If the batteries fail, you’ll receive BATT FAILED message under the ALR submenu. In this case, make
sure that the battery circuit breaker is “ON”/”I”, charge the batteries for minimum 10 hours and repeat
the test. If the alarm persists, consult technical service for replacement.
Make sure that the batteries are fully charged and battery circuit breaker is “ON”/”I” before
starting battery test. Otherwise, the batteries will fail even if they are in good condition.
BATT FAILED message will not disappear until another successful test is performed.
