Emerson Liebert NXC 10-20kVA, Connection Manual, Page: 2 / 3

1.2 Connection Cables For Dry Contact Port
The UPS provides five dry contact ports; see Figure 1-1 for the specific positions. The silk prints of the five dry
contact ports are 1, 2, 3, 4 and 5. The pin layout of each dry contact port is shown in Figure 1-3, and the port
description is shown in Table
+12V +12V +12V
SA
L
A
R
M
GN
D
O
n_bat
ter
y
GN
D
O
n_bapas
s
GN
D
E
po_N
C
+12V +12V
Epo_I
N
BFP
_
o
BFP_s BFP_c
Dry contact port1 Dry contact port 2 Dry contact port 3 Dry contact port 4 Dry contact port 5
Table 1-1 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 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
backfeed
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 short 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 stop 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.
Figure 1
‐
3 Pin layout of dry contact ports