14
3. Installation and Wiring
Dual Input (Single Unit)
When there are two AC power sources, single unit wiring procedures are as follows:
1
Follow
3.6.4 Dual Input Modification
to modify the UPS for dual input. Only experienced engineers or service personnel should
modify single input/dual input setup. For dual input, the main AC source’s Neutral (N) must be connected with the bypass source’s
Neutral (N).
2
Follow steps
1
~
5
in section
Single Input (Single Unit)
.
3
Connect the main AC source/bypass AC source/output/external battery cabinet cables to the wiring terminal block and do not forget
to ground the UPS (refer to
Figures 3-13~3-18
).
4
Follow steps
7
~
8
in section
Single Input (Single Unit)
.
BYPASS BREAKER
INPUT BREAKER
UPS OUTPUT
N
T
S
R
-
N
240V DC 240V DC
AC INPUT
N
T
S
R
+
BATTERY INPUT
R
S
T
N
R
S
T
N
I
O
ON
OFF
I
O
ON
OFF
I
O
ON
OFF
I
O
ON
OFF
I
O
ON
OFF
I
O
ON
OFF
I
O
ON
OFF
I
O
ON
OFF
Connects the bypass source
Protective
Device
4-Pole
Contactor
R S T N
R S T N
R S T N
CS
(*CS:
Contactor
Solenoid)
(20kVA Model)
+
N
-
Protective
Device
(Disconnect
Device)
Connects
an external
battery
cabinet
(if necessary)
For the external
battery cabinet’s
grounding( )
For the critical
loads’ grounding ( )
For the
UPS
grounding
( )
R S T N
Connects the main AC source
Protective
Device
4-Pole
Contactor
R S T N
R S T N
CS
(*CS:
Contactor
Solenoid)
Connects the
critical loads
N
T
S
R
3-Pole Breaker
(Figure 3-9: 20kVA UPS Single Unit Dual Input Wiring Diagram I )
SUTX20K
