DCU20
User Manual rev. 19
Page 5/29
1 System description
Use latest device Documentation, Software and Firmware to ensure reliable operation of
the system (downloadable from www.nextys.com).
The DCU20 is a microprocessor controlled DC UPS rated 20A (
rating of the
power supply
connectable to the input
) usable in systems with a nominal voltage between 12V and 28V.
The DCU20 monitors the voltage coming from a DC power supply and in case of power failure a
backup battery is connected to the load. In normal condition the battery is kept charged by an
integrated battery charger supporting various battery chemistries such Lead-Acid, NiMH, NiCd and
Lithium.
1.
Alarm LED
indicator: It is
ON
when the unit is
in backup. It blinks at 1Hz rate in case of
error.
2.
USB Port
: Used to connect a PC running the
POWERMASTER
application
for
remote
monitoring and controlling. Firmware update is
also possible through USB connection.
3.
Temperature sensor
connection: Used to
connect a temperature sensor (P/N: WNTC-
2MT) to measure the battery temperature for
protection and temperature compensated
charge method.
4.
Relays dry contacts
: 2 relays are present for
remote monitoring. See §3.1 for more details.
5.
Inhibit input
: A signal between 5VDC and
30VDC applied to this input inhibits the
backup function; this input is programmable to
be active high or active low (see §4.5).
6.
“Battery sense” connection
: Used to
accurately sense the battery voltage by
considering the cables voltage drop. It is
recommended to use this input when the
battery internal resistance measurement is
needed (see §4.7).
7.
Input connection
: 2 poles are provided for
input connection. This must be connected to a
power supply rated 12…28VDC with a
maximum rated current of 20A (see §4.2).
8.
Output connection
: 2 poles are provided for
output connection. It must be connected to the
load to be backed up with a maximum rated
current of 20A (see §4.2).
9.
Battery connection
: 2 poles are provided for battery connection. This must be connected to
the battery. Although the unit is protected, please respect the correct polarity. (see §4.3)
10.
Display
“Input” area:
provides information regarding the
unit’s input (see §5.1).
11.
Display
“Output” area:
provides information regarding the unit’s output (see §5.1).
12.
Display
“Battery” area:
provides information regarding the battery (see §5.1).
13.
Control keys:
4 push buttons are provided to navigate through the menus and to select the
various functions.
1
2
3
4
5
6
7
8
9
10
11
12
13
Figure 1: Front panel view
5
DCU20_1680-21539-0006-E-1117
