DCU20
User Manual rev. 21
Page 7/29
3 Functional description
A simplified block diagram of the DCU20 is shown in Figure 2.
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
D
D
C
C
B
B
A
A
DC-UPS_V0.1.SchDoc
Title
Size
Date
File
Document NumberRev ision
Sheetof
Drawn By
DCU20 - 20A 12/24V DC-UPS Simplified Block Diagram
A3
doc_number
V0.1
1
1
Marco Geri
11/07/2012
NEXTYS
V
A
A
V
V
A
R
e
v
e
rs
e
P
o
la
ri
ty
B
a
tt
e
ry
h
e
a
lt
h
M
o
n
it
o
r
5A Battery
Charger
Microprocessor
Buttons
Relay s
USB
Thermal
Display
Buzzer
OUT
IN
BATT
THR
USB
READY
BACKUP
Figure 2: DCU20 simplified block diagram
DCU20 is a high performance digitally controlled DC-UPS that can be used in any DC system with a
rated voltage between
12V
and
28V
and up to
20A
of input current.
It includes a battery charger capable of charging Lead-Acid, Ni-MH and Li-ION batteries with a rated
voltage between 12V and 28V and able to deliver a charge current up to 5A.
The input voltage is continuously monitored by the microprocessor. In case of a power outage the
battery is connected to the load instantaneously through an active switch, reducing the power loss to
a minimum.
The product offers
additional features
to improve the performance and the reliability of the system,
which are described below.
3.1 Remote monitoring and controlling
3.1.1 USB
The
USB
interface allows the communication with the proprietary
POWERMASTER
software (available
for download at
www.nextys.com
) which allows the full control and monitoring of the DCU20 unit with
the ease of the PC.
3.1.2 Digital input
An
opto-isolated input
allows the inhibition of the backup function. The polarity of the input can be
defined using the Inhibit polarity setting (see §5.2.15).
3.1.3 Dry contact outputs
2 relays are present on the DCU20. User can chose which event activates the relay and the polarity.
The list of events is the following:
