Symmetra MW II 1200 kW 3 x 400/230 V Installation - 990-1979E-00120
Torque specifications
Required Breaker Settings (400 V Systems)Note: Contact APC Application Team for Required Breaker Settings in 380 V and 415 V
systems.
The Symmetra® MW is a fault-tolerant system capable of handling and surviving overloads and
internal/external faults. The overload performances and fault clearings are possible when the system
meets specified minimum requirements for breaker settings.
A proper breaker coordination study is required to ensure the highest availability of the UPS. This
breaker coordination study should be performed focusing on maintaining the fault tolerant characteristics
of the Symmetra MW.
The following tables provide the optimum settings for the input and output breakers. The settings are
specified in the tables below, but some of them can also be found in the Electrical Specification section.
See separate manual on parallel operation for information on required breaker settings in
parallel systems.
Input and upstream breakers
Torque specifications
Bolt Size M8 13.5 Nm
Bolt Size M10 30 Nm
Bolt Size M12 50 Nm
Bolt Size M14 75 Nm
Q1, Q5, and any upstream breaker
Duration [S] Current [A] Total load [%] Event/Operation
< 0.005 22 kA -- Internal fault clearing
2200* 127 Overload on-line
1793 100 On-line
1972 110 On-line+ Max. Battery
charge
* In the absence if a coordination study conducted by a professional engineer, the recommended
instantaneous trip setting for breakers Q1, Q2, Q4, Q5, and Q6 is 22 kA
** Only applicable to Q1
∞
∞
∞