Tap Position Sensor — optical OLTC position sensor and MOD-0013 / MOD-0014 display
The OLTC position sensor of a power transformer is based on an optical encoder, with an optional MOD-0013 or MOD-0014 display. The interface is Modbus RS-485, and the display adds a 4–20 mA current loop, powered from 24 V DC or 120 V AC. Mounting kits SEN-0001, SEN-0002, SEN-0003, SEN-0017 and ELC-0010 suit the drives of most OLTC manufacturers.
- Principle
- optical encoder
- Power supply of sensor and display
- 24 V DC or 120 V AC
- Operating temperature of sensor
- from −40 to 70 °C
- Sensor interface
- Modbus (RS-485)
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
The position sensor for the OLTC of a power transformer is built on an optical encoder and is supplied with an additional display. It provides accurate information on the tap position in real time and eliminates the typical failures of analogue sensors of earlier generations. Optical isolation and a robust design make it resistant to lightning strikes and switching overvoltages, and the sensor does not need to be disconnected during impulse tests of the transformer. It is designed for the harsh conditions of substations.
Setup is done with software: a common tap changer type is selected from a drop-down list, and the remaining parameters are filled in automatically. For other tap changers an advanced mode is provided, in which the sensor is configured for any application. The sensor transmits data over Modbus (RS-485) directly to C50 or E3 transformer monitors, so no separate indicator is needed. Power supply 24 V DC or 120 V AC, operating temperature from −40 to 70 °C.
The additional MOD-0013 (24 V DC) or MOD-0014 (120 V AC) display with backlight has a two-line seven-segment LED indicator with eight brightness levels for local indication of the position. Remotely, the position is transmitted over Modbus RS-485 or a 4–20 mA current loop powered by the loop, so the display also works with monitors of other manufacturers. The 1/8 DIN format display replaces the 1250B indicator with minimal modifications.
The sensor is offered as a direct replacement for legacy position sensors 1292KS, M-2948 and others. Mounting kits are available for the drives of most large OLTC manufacturers. SEN-0001 has a standard bracket and a coupling for a 3/16″ shaft, and its L-shaped bracket matches the mounting position of the 1292KS sensor. SEN-0002 has a bracket for the UZD tap changer without an additional Maltese cross gear. SEN-0003 comes with a flexible adapter 9 or 12 inches long and couplings of 0.25, 0.375 or 0.5 inch. SEN-0017 is designed for the MD-III drive typical of the RMV-II tap changer, and ELC-0010 is supplied without a bracket. Modernisation with the existing installation space preserved is carried out with support from the manufacturer's service.
Technical specifications
| Principle | optical encoder |
|---|---|
| Power supply of sensor and display | 24 V DC or 120 V AC |
| Operating temperature of sensor | from −40 to 70 °C |
| Sensor interface | Modbus (RS-485) |
| Display outputs | Modbus (RS-485), 4–20 mA (powered from the current loop) |
| Display | 7-segment two-line LED, 8 brightness levels, 1/8 DIN format |
| Shaft | 3/16″ |
| Mounting versions | SEN-0001 standard bracket; SEN-0002 for UZD; SEN-0003 flexible adapter; SEN-0017 for MD-III drive; ELC-0010 without bracket |
Request a price and lead time
Tap Position Sensor — optical OLTC position sensor and MOD-0013 / MOD-0014 display. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Questions and answers
How is the tap position sensor connected to a transformer monitor?
Over Modbus (RS-485) directly to the C50 or E3 monitors, so no separate display is required. The MOD-0013 or MOD-0014 display can be added for local indication.
What power supply is required and what temperature range does the sensor work in?
The sensor and display are powered from 24 V DC or 120 V AC. The operating temperature of the sensor is from −40 to 70 °C.
What outputs does the display have and what is its format?
The display has Modbus RS-485 and 4–20 mA outputs, with the current loop powering the 4–20 mA output. The format is 1/8 DIN, with a two-line LED indicator and 8 brightness levels.
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