Specifications

14.1.6Electrical Requirements

Table 23 Electrical requirements

Item

Requirement

Maximum Continuous Current

250, 400, 600, 800 amps

 

 

Load Power Factor Range

0.75 to 1.0, leading or lagging

 

 

Load Crest Factor

Up to 3.5

 

 

Source Voltage Distortion

Up to 10% THD with notches and ringing transients

 

 

 

125% for 30 minutes 250A-400A

 

 

Overload Capability

125% for 10 minutes 600A-800A

 

150% for 2 minutes

 

 

 

 

500% for 0.25 sec

 

 

Table 24 Unit short circuit withstand capability

Unit Voltage

Unit Amps

Withstand Capability

 

 

 

 

250A

100kA

 

 

 

208-240V

400-600A

100kA

 

 

 

 

800A

100kA

 

 

 

 

250A

65kA

 

 

 

380-480V

400-600A

100kA

 

 

 

 

800A

65kA

 

 

 

 

250A

25kA

 

 

 

600V

400-600A

25kA

 

 

 

 

800A

42kA

 

 

 

14.1.7Surge Suppression

The static transfer switch is equipped with transient voltage surge suppression on each input for surge suppression. The surge suppression is capable of protecting the static transfer switch from operating outside of tolerances due to surges as defined by IEC 1000-4-5 (1.2/50uS surge, 2kV CM and 1kV DM) as required under EN 50091-2. Optional surge suppression modules (TVSS) are available for each input of the STS2/PDU for surge protection of the transformers.

14.1.8Response Time

A dual level fast/slow transfer threshold is used for under voltage detection to allow the STS2/PDU to be compatible with UPSs and generators. The voltage thresholds and the slow transfer delay time is user-adjustable. The fast transfer delay time is less than 4 ms.

The over voltage detection uses a single threshold, with programmable level and delay time. See User Settings on page 101 for instructions on configuring these settings.

14.1.9Environmental Requirements

See 3.0 - Locating The STS2/PDU for details concerning environmental requirements for the STS2/ PDU.

14.2System Components

All STS2/PDU models provide two isolation transformers connected to a solid-state, three-pole dual- position static transfer switch within one enclosure, with the ability to transfer between two input sources to a single output.

All STS2/PDUs are configured with an LCD Color Graphical Interface touch screen display for moni- toring and configuring the unit.

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Liebert PDUTM System Components, Electrical Requirements, Surge Suppression, Response Time, Environmental Requirements