-
6
-
2. Notes for correct operation
2.1 Notes for input power supply
(1) Always use the correct AC input power supply corresponding to the equipment rating.
(208V within
±
15%, 50 or 60Hz within
±
5%).
(2) The capacity of the input power supply must be larger than the required capacity of
the UPS.
(3) Install the breaker (ASD70S2U/35S2NU:75A, 100S2U/70S2NU:100A,
140S2U/100S2NU:125A) for the distribution board of the UL authorization.
(4) To have the potential of the ground of the computer system and the UPS correctly used,
connect with UPS according to the exchange input power supply kind of table.
①
Investigation of AC input power supply
Investigate to which in the table the exchange input power supply used corresponds
beforehand. Measure the voltage of ground with the tester etc. if it is uncertain.
②
Input wiring construction
Wire after selecting connected line(phase) to input terminal L and N of UPS so that
“Fit” in the table may become
○
or
△
.
○
: Standard of non-grounded power supply and single-wire ground power supply.
△
: Voltage of ground is caused (not excessive) in the UPS output terminal.
If the
single-wire ground is done on the load side, the power supply is short-
circuited.
×
: The voltage of ground of the UPS output terminal becomes excessive,
and causes the breakdown of the load.
Change wiring to
○
or
△
, because
single-wire ground on the load side becomes
the power supply short-circuited.
Or, add the insulation transformer to the output side.
Connections
to UPS
UPS output
voltage to ground
※１
Input power
source
R
S
Fit
U-G
V-G
Notes
A B
B A
B C
C B
C A
1 3-phase
ungrounded
power source
A C
○
See Note
See Note
A B
2 Single-phase
ungrounded
power source
B A
○
See Note
See Note
Ground voltage is unstable (floating
voltage).
Output voltage to ground:
V
Ｕ
-
Ｇ
＋
V
Ｖ
-
Ｇ
＝
a. 208V
A
C
B
○
a. 208V
a. 0V
A C
C A
×
a. 208V
(a. 416V)
a. 208V
A
3 3-phase
grounded
power source
B
C
×
a.
0V
(a. 416V)
a. 208V
A B
○
a. 208V
a. 0V
4 Single-phase
grounded
power source
B A
×
a. 0V
(a. 416V)
a. 208V
1. Connect the ground phase to the S input
terminal on the UPS.
2. If the S terminal is not connected to the
ground phase:
(1) The ground voltage is high when the
inverter is not synchronized whit the AC
input.
(2) A single-wire grounded load connected to
the UPS output side short-circuits the
power source.
A B
5 Neutral grounded
power source
single-phase,
3-wire
B A
△
a. 104V
(a. 312V)
a. 104V
A B
B A
B C
C B
C A
6 Neutral grounded
power source
3-phase 4-wire
A C
△
a. 120V
(a. 320V)
a. 120V
1. The ground voltage is high when the
inverter is not synchronized whit the AC
input.
2. A single-wire grounded load connected to
the UPS output side short-circuits the
power source.
A
C
B
×
a. 104V
(a. 390V)
a. 180V
A
B
C
A C
7 Neutral grounded
power source
3-phase 3-wire
C A
△
a. 104V
(a. 312V)
a. 104V
1. The ground voltage is high when the
inverter is not synchronized whit the AC
input.
2. A single-wire grounded load connected to
the UPS output side short-circuits the
power source.
Ｃ
Ｂ
Ａ
Ｃ
Ｂ
Ａ
Ｂ
Ａ
Ｃ
Ｂ
Ａ
Ｃ
Ｂ
Ａ
Ｃ
Ｂ
Ａ
Ｂ
Ａ
Ｂ
Ａ
Ｃ
Ｂ
Ａ
※
1 The voltage in parentheses is a maximum voltage at not synchronized with the AC input.
