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8th3
Digital Inputs (UPS OFF and GEN ON)
Voltage to be applied to the digital inputs is 5V DC. Maximum current drawn by each input is 1 mA.
5V DC supply provided on the communication interface board can be used to supply both digital inputs.
Pay attention to the polarity of the voltages applied to the digital input terminals.
Input
Function
UPS OFF
If the UPS OFF input is set high by applying 5V DC voltage on the related
terminals, UPS stops generating the output voltage and stops feeding the load.
When the voltage on the digital input is removed, the UPS starts up according
to the normal procedure.
GEN ON
If the GEN ON input is set high by applying 5V DC voltage on the related
terminals, UPS smoothly increases the current drawn from the generator
during transitions from battery mode to normal mode.
8th4
Free Contact Communication
Free contact relay connection cables shall have a cross-section of 1.5 mm
2
.
Maximum voltage to be applied to the relay contacts is 42V AC rms (sinus) or 60 Vdc. Maximum
contact current depends on the applied voltage and the load characteristic. Both maximum
voltage and maximum contact current corresponding to the applied voltage shall not be
exceeded.
Maximum allowed resistive contact currents for several voltages are given on the table below:
Applied voltage
Maximum contact current for resistive load
Up to 42 V AC
16 A
Up to 20 V DC
16 A
30 V DC
6 A
40 V DC
2 A
50 V DC
1 A
60 V DC
0.8 A
Each relay has both a normally open (NO) and a normally closed (NC) contact. One end of these contacts
is common. Normal states of the relay contacts are shown on the figure at the beginning of the
“communications” section.
Relay functions are described below:
Relay
Function
ACFR (AC failure relay)
Contacts change position if the rms value or frequency of the
mains voltage is beyond their limits.
BYPR (Bypass relay)
Contacts change position if the UPS is working in the bypass
mode
BUVR (Battery under voltage relay)
Contacts change position if the battery voltages are critically low
to feed the load and the load power is about to be interrupted
SBFR (secure bus failure relay)
Contacts change position, if the output voltage disappears
