4 grounding, 5 electrical requirements, Table 19 electrical requirements – Liebert POWER PROTECTION STATIC TRANSFER SWITCH User Manual
Page 119: Table 20 unit short circuit withstand capability, 6 input surge suppression, 7 response time, 8 environmental requirements, Table 19, Electrical requirements, Table 20

Specifications
111
15.1.4 Grounding
Refer to 5.3 - System Grounding for specifications and instructions regarding grounding.
15.1.5 Electrical Requirements
15.1.6 Input Surge Suppression
The STS2 is equipped with transient voltage surge suppression on each input for maximum surge
suppression. The surge suppression is capable of protecting the STS2 from operating outside of toler-
ances 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.
15.1.7 Response Time
A dual level fast/slow transfer threshold is used for under voltage detection to allow the STS2 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 89 for instructions on configuring these settings.
15.1.8 Environmental Requirements
See 3.0 - Location Considerations for details concerning environmental requirements for the
STS2.
Table 19
Electrical Requirements
Item
Requirement
Maximum Continuous Current
100, 250, 400, 600, 800, 1000 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
Overload Capability
125% for 30 minutes 100A-400A
125% for 10 minutes 600A-1000A
150% for 2 minutes
500% for 0.25 sec.
Table 20
Unit Short Circuit Withstand Capability
Unit Voltage
Unit Amps
Withstand Capability
100-250A
100kA
208-240V
400-600A
100kA
800-1000A
100kA
380-480V
100-250A
65kA
400-600A
100kA
800-1000A
65kA
100-250A
25kA
600V
400-600A
25kA
800-1000A
42kA