User Manual

Hipulse - Single Phase ‘1+N’ UPS System

130 kVA - 110V

WARNING

Failure to follow adequate earthing procedures can result in electric shock hazard to personnel, or the risk of fire, should an earth fault occur.

3.1.6Protective devices

For safety reasons, it is necessary to install, external to the UPS, circuit breaking protective devices in the input a.c. supply and towards the battery. Given that every installation has its own characteristics, this chapter provides general useful information engineers, with knowledge of operating practices, of regulatory standards, and of the equipment to be installed.

Rectifier and bypass inputs:

Protection against excessive over currents and short circuits

These inputs must be protected, installing suitable protective devices at the distribution panel of the incoming main supply, considering that the protection should discriminate with overload capacity of the system (see Chapter 9: Specification - Electrical Characteristics).

Split Bypass :

In the case of a split bypass being used, separate protective devices should be installed in the incoming mains distribution panel.

The protective devices must be selected for the nominal input current, with respect to the UPS rating and the input a.c. supply voltage as given in table 3-1.

Protection against earth faults (RCD devices):

In the event of a differential (RCD) device being installed upstream of the input supply, one must take into account transient and steady state earth leakage currents that are produced during start-up of the UPS.

The presence of an RFI suppression filter inside the UPS, determines a residual earth current greater than 3.5mA and less than 1000mA.

Residual current circuit breakers (RCCB) must be sensitive to d.c. unidirectional pulse (class A) in the network and insensitive to transient current pulses.

They are identified by the symbols respectively.

These isolators must have an average sensitivity, possible adjustable between 0.3 and 1A.

It is recommended that the selectivity with every differential switch be verified both upstream of the input distribution board and downstream (towards the load).

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Liebert 130 kVA user manual Protective devices, Split Bypass, Protection against earth faults RCD devices