3. Installation and Wiring
3.6 Wiring
3.6.1 Precautions Prior to Wiring
• The wiring must be performed by qualified professional personnel.
• Before wiring or making any electrical connection, make sure the power supplied to the input and output of the UPS is completely cut
off and the internal battery connectors are disconnected.
• When connecting the UPS to the utility AC power and bypass source, protective devices and 4-pole connectors must be installed. The
protective devices and 4-pole contactors must use approved components that meet safety certifications. Please refer to the following
table for suggested protective devices. For the installation of the protective devices and 4-pole contactors, see Figures 3-10~3-18.
UPS System
SUT20K
SUT30K
SUT40K
SUT60K
• When connecting the critical loads to the UPS, a listed certified breaker must be installed between them. Refer to the table below
UPS System
SUT20K
SUT30K
SUT40K
SUT60K
• Check that the size, diameter, phase and polarity of each cable connecting to the UPS is correct. For the specifications of input/output
cables and circuit breakers, refer to Table 3-1.
Table 3-1: Specifications of Input/Output Cables and Circuit Breakers
AC Input Cable*
Output Cable*
Battery Input Cable*
Tightening Torque
Input Breaker
* Use only copper wire rated to 194°F (90°C) or higher
Notes:
1. In accordance with local electrical codes, install a suitable conduit and bushing.
2. Please refer to national and local electrical codes for acceptable non-fuse breakers and cable size.
3. Cables with PVC material and with temperature resistance up to 201°F (105°C) are suggested.
4. Make sure that the input/output cables are locked tightly.
• When connecting with the external battery cabinet, confirm the polarity. Do not reverse the polarity.
• The grounding cable of the external battery cabinet must be connected to the (
• Installer should consider the maximum current and wiring gauge that may be required for future expansion of parallel configurations.
• The input of the UPS must be a Y connection, and the neutral line (N) must be connected to avoid UPS failure. Do not connect the
neutral line (N) of the UPS with the ground terminal (
• If there is a floating voltage between the input power's neutral (N) and the ground (
should be zero, it is suggested an installation transformer be installed in front of the UPS input side and the UPS neutral (N) be
connected with the ground (
• The utility AC power must be three phases (R/S/T) and meet the specifications on the UPS rating label. When connecting the utility
input power to the UPS, make sure it is in positive phase sequence (clockwise phase rotation).
• Connect the external battery cabinet's grounding terminal to the grounding terminal (
Do not connect the grounding terminal of the external battery cabinet to any other grounding system.
• The ground terminal (
) of the UPS must be grounded. Use ring-type terminal for wiring.
SUT20K
2
2 AWG (25 mm
)
2
2 AWG (25 mm
)
2
1 AWG (35 mm
)
130 in. lb. (14.7 N·m)
75A (3-pole x 1)
).
).
Recommended Protective Device
D-Curve 75A circuit breaker
D-Curve 125A circuit breaker
D-Curve 150A circuit breaker
D-Curve 225A circuit breaker
Recommended 3-Pole Breaker
C-Curve 75A circuit breaker
C-Curve 125A circuit breaker
C-Curve 150A circuit breaker
C-Curve 225A circuit breaker
SUT30K
2
1/0 AWG (50 mm
)
3/0 AWG (95 mm
2
1/0 AWG (50 mm
)
3/0 AWG (95 mm
2
1/0 AWG (50 mm
)
3/0 AWG (95 mm
130 in. lb. (14.7 N·m) 130 in. lb. (14.7 N·m) 130 in. lb. (14.7 N·m)
125A (3-pole x 1)
150A (3-pole x 1)
) terminal of the battery terminal block.
) and you require that the VNG of the UPS
) of the UPS system's battery terminal block.
10
SUT40K
SUT60K
2
)
250 kcmil (120 mm
2
)
250 kcmil (120 mm
2
)
250 kcmil (120 mm
225A (3-pole x 1)
2
)
2
)
2
)