American Power Conversion SYMF800KH User Manual

Page 38

Specifications: Required Breaker Settings (400 V Systems)

Symmetra MW 800 kW 3 × 400/230 V Installation - 990-1510D

22 kA is the maximum peak let-through current (including safety factor) available during clearing of
an internal fault in a 200 kW section or a Power Module. During or after a controlled fault clearing,
none of the breakers are allowed to trip on the instantaneous trip setting below the specified value.
This is also applicable to the upstream breakers, and a control of the instantaneous trip setting in this
part of the installation is required. The maximum peak let through current is applicable to utility with
prospective short-circuit currents up to 200 kA.

The diagram shows a dual mains systems in which the upstream breakers are named Q. Correct
settings of upstream breaker settings are mandatory. The systems can also be configured as single
mains systems.

Note

The instantaneous trip setting must not be derated even though the UPS system is derated
in system output power. The system size has no influence on the instantaneous trip
setting.

Note

For derated or parallel systems, the APC Application Team provides the correct breaker
settings and breaker frame sizes.

Note

For upstream breakers not mentioned in the table, the APC Application Team provides
the correct breaker settings for on-line, overload, and trip currents.

Dual Mains Single Installation