Step indicator SI4100

Step indicator SI4100

SI4100 is digital measuring, fully programmable device from series 4100, designed on basis of microcontrollers. SI4100 shows the current position of the tap changer of the high-voltage transformer in electrical substations. The unit is part of tap changer-motor drive equipment. The position of the tap changer can be read either analogue (by resistor matrix) or digital (BIN or BCD input). The unit is designed to be mounted on boards in control rooms of electrical substations.

user manual


SI4100 is offered in following variety*:

- (A/D) basic option - reads and shows current tap changer step
A analogue input (resistor matrix)
D digital BIN or BCD input
B digital BIN or BCD output for remote signalization
C code-protected user menu
X user is not allowed to change device settings
* - Every option can be ordered in any combination with other options, excluding versions “А” and “D”. One of the options - “А” or “D” must be chosen.

Main technical parameters of SI4100

input analog / BIN / BCD
digital input voltage range 5-48 VDC
analogue input single resistor step 6/ 8/ 10 Ohm
analogue input maximum matrix resistance 390 Ohm
analogue input maximum steps 39 when 10 Ohm; 48 when 8 Ohm; 64 when 6 Ohm
digital input maximum steps 127 when BIN-input; 79 when BCD-input
maximum wiring length * 200 m / 0.75mm2; 400m / 1.5 mm2; 700m / 2.5 mm2
power supply 55-250 VAC (80-350 VDC)/ 30-270 VAC (42-380 VDC)
display super bright red, 4-digit, 94х29 mm visible, purple filter
power consumption < 3 W
work temperature from 0° C to 55° C
storage temperature from -50° C to +90° C
dimensions (H/W/D) 144/144/65 mm (w/o plugs); 144/144/75 mm (with plugs)
mounting hole (H/W) 136/136 mm quad, centered
protection class IP52 front, IP31 back
own weight 320 g

Normal mode of operation

User-defined parameters

  • input type - analogue/ BIN/ BCD
  • digital input polarity
  • output type - BIN/BCD and relay polarity (NO/NC)
  • maximum steps at analogue input
  • analogue input single resistor step
  • display blinking
  • separate step display
  • saved preset data entry