INFORM STATIC TRANSFER SWITCH
3Phase in - 3Phase out
50Amp to 400Amp
InfoSTS is a microprocessor controlled transfer switch, designed for automatic and manual switching between
two AC power sources, with interruption to the load of less than 2 msecs with synchronized sources and of less
than 12 msecs for unsynchronized sources.
STS utilizes SCRs connected in opposite parallel pairs (six pairs for 6 pole models ,eight pairs for 4 pole
models) . Three or four pairs of SCRs are used to connect the AC load to the power supply input referred to as
"PREFERRED", under normal conditions. The other three (of four) pairs of SCRs are on standby to transfer the
load to the other power supply input referred to as "ALTERNATE" in case of a failure of the "PREFERRED"
input supply.
Source 1 and Source 2 supply inputs should come from two different AC sources with nominally identical
voltages, phases and frequencies. The aim of the STS is uninterrupted transfer from one AC power supply to
the other, in case of a fault in the "PREFERRED" supply.
Before and during transfer from one source to the other, the operating conditions of the SCRs are carefully
monitored to prevent crosscurrents between two sources. The break-before-make technique makes healthy and
uninterrupted transfers possible.
" Increased power quality
" Easy monitoring all parameters on LCD display
" Fast microcontroller (32 mips)
" Power blackout protection
" Automatic static switching
" Remote monitoring of input power sources
" Easy static and mechanical transfer between separate input sources
" Remote management of power events
" Power event logging
" Advanced RS232 communication features
" DRY contact alarm interface
" Password protected login system from remote site (timed Access)
" 2 redundant power supplies form electronic boards (hot swappable)
" Easy front access to all components inside of the STS
" Second protection cover on live circuits which prevents electrical shock
" Input sources protected by fuses
" 3 positioned Maintenance bypass switch which prevents cross currents between input sources
" User adjustable parameters by entering a password
" Built in real time clock
" Alarm history (with their date and time)
" Automatic transfer test from a remote site or using front panel
" External emergency shutdown (EPO) input
" Hot plug construction during maintenance bypass
" High current output tolerant up to 1000%
" Temperature sensor inside the Cabinet
" Fast voltage black-out circuit
" Input phase balance and phase sequence fault detect circuit
" Adjustable Input source frequency lower/upper limits
