User Manual 10H52188UM51 - Rev. 1 - 09/2011
51
Liebert NXC
Communication
Table 6-1 Description of the dry contact ports
Silk print
Port name
Pin NO.
Pin name
Meaning
1
Output port of alarm
1.1
S_ALARM
The signal level is 12V when the system alarms
1.2 GND
GND
2
Output port of battery
status
2.1 ON_BATTERY
The signal level is 12V when the system runs in battery
inversion mode
2.2 GND
GND
3
Output port of bypass
status
3.1
ON_BYPASS
The level is 12V when the system runs in bypass mode
3.2 GND
GND
4
Input port of remote
EPO*
4.1
EPO_NC
EPO activated when opened to 4.2
4.2
＋
12V
EPO activated when opened to 4.1
4.3
＋
12V
EPO activated when shorted to 4.4
4.4
EPO_IN
EPO activated when shorted to 4.3
5
Output port of bypass
reflected
5.1 BFP_O
Bypass backfeed protection relay (normally open).
Closes when short circuit of bypass silicon controlled
rectifier (SCR) leads to backfeed
5.2 BFP_S
The middle point of the bypass backfeed protection
relay
5.3 BFP_C
Bypass backfeed protection relay (normally open).
Opens when shoft circuit of bypass SCR leads to
backfeed
Note*:
Pin1 and pin2, or pin3 and pin4 of the dry contact port 4 reserves the corresponding terminals for configuring the REPO function.
The REPO device also needs the shielded cable to connect to the normally open/closed remote REPO switch between the two
terminals. If not necessary, you should disconnect pin3 and pin4 of the dry contact port 4, or short pin1 and pin2 of the dry contact
port 4. Pin1 and pin2 of the dry contact port 4 have been shorted before delivery
Note
The EPO action of the UPS will close the rectifier, inverter and static bypass, but it cannot disconnect the UPS mains input inside. If
you want to disconnect the UPS completely, just disconnect the upstream input MCB when generating the EPO.
In emergency conditions, close the REPO switch (prepared by users) to shut down the rectifier and inverter, and the UPS is
powered off. In normal condition, the REPO switch cannot cut off the UPS input power. If a switch of electronic control tripping
function is adopted at the UPS input, the REPO switch can help the switch trip and thus cut off the UPS input power. The
position of the REPO switch is shown in Figure 1-3, and the REPO cable connection is shown in Figure 6-3.
Figure 6-3 REPO cable connection
The cable connection procedures are as follows:
1. Loosen the “+12V” and “EPO_IN” connection terminals of the REPO port.
2. Insert the two ends of the copper core cables with the insulation leather peeled into the “+12V” and “EPO_IN” connection
terminals of the REPO port, and press down the terminals. The REPO cable is complete. Ensure that the REPO cable is firmly
connected to avoid no action or wrong action of the REPO caused by accidental dropping or infirm contact.
3. For parallel UPSs, when connecting the REPO cable, users should parallel connect “+12V” of the REPO port with one end of
the electronic switch, and parallel connect “EPO_IN” with the other end of the electronic switch. Note the difference between
the port silkscreen “+” and “-” during connection.
When the REPO switch at the user end closes, the UPS will generate an alarm and cut off the output immediately, and the UPS
will not return to the normal operation state automatically. At this point, you must change the REPO switch state, and power on
the UPS manually.
REPO switch
REPO plug
