The TECNED ST (SF/D) Static Transfer Switch series is available with single phase input /output and

current ratings from 25A to 500A.

The ST (SF/D) series can be supplied as a 1-pole or 2-pole static switch to meet customer

requirements for safety and reliability. Standard features include source select, auto source and

source lock, input V metering, mains S1-S2 out of tolerance alarm and general alarm with potential free contacts.

The ST (D) includes a digital controller with LCD display that shows the systems current state of

operation and system values, allows setting of system parameters and includes event and alarm logs.

Contact us


Option list ST (SF/D)

  • Extend to 12x PFC (NO/NC) with LED
  • Mimic diagram with Individual fuse/breaker failure indicator
  • Fan failure alarm
  • 3-position mechanical bypass
  • Up to 6 (DIN 96) meters / cabinet
Specifications ST (SF/D) 25-500A
Input Voltage

110/120/200/220/230/240/277V, (2W+E)

Voltage tolerance

180 / 264 Vac (Ph-N)


50Hz / 60Hz

Frequency window

2-10% adjustable

Output Transfer type

Break before make

Transfer methods

Automatic / Manual / Remote

Transfer time

< 4 msec (S1-S2 synchronized)

< 11 msec (S1-S2 not synchronized)


150% for 1 min. / 200% 10 seconds

Power Factor

0.6 lag to 0.9 lead

General Ambient temperature

-20 to +70 °C storage / -10 to +40 °C operation

Altitude above sea level

1000 m


Aluzinc frame / powder coat RAL 7035


Safety IEC/EN 62040-1 / EMC 55011


IEC 60146 / CE-Label