ABB Bailey LPS01 Turbine Position Module

This turbine position module monitors steam turbine valve positions for ABB Bailey INFI 90 systems. It interfaces directly with linear variable differential transformers (LVDTs). Therefore, it enables precise control of turbine governor valves and stop valves.

Physical and Input Specifications

The ABB Bailey LPS01 measures 25.0 cm in length and 18.0 cm in width. Moreover, its module weight equals approximately 0.88 kg for rack mounting. A single 48-pin male connector links this module to the INFI 90 backplane. Additionally, the unit includes four independent LVDT input channels.

Parameter	Specification
Brand	ABB Bailey
Full Model	LPS01
Category	Turbine Position Module
Dimensions (L x W x H)	25.0 cm x 18.0 cm x 5.5 cm (9.84″ x 7.09″ x 2.17″)
Module Weight	0.88 kg (1.94 lbs)
Backplane Interface	1 x 48-pin Male Connector (INFI 90 Rack)
Power Supply Input	5 VDC from Backplane (0.9 A Typical) + 24 VDC External
Power Consumption	4.5 W + 5 W (External)
LVDT Input Channels	4 Independent Channels
LVDT Excitation	5 kHz Sine Wave, 3 Vrms (Programmable Amplitude)
Input Signal Type	Differential AC (Primary + Secondary)
Input Impedance	10 kΩ per Channel
Input Voltage Range	0 to 5 Vrms (Secondary Signal)
Position Measurement Range	±25 mm (Depending on LVDT Sensor)
Resolution	16 Bits (0 to 65535 Counts)
Accuracy	±0.1% of Full Scale
Update Rate	10 ms per Channel (40 ms for All 4 Channels)
Filtering	Programmable (0 to 100 Hz Low-Pass)
On-Board Components	4 LVDT Signal Conditioners + 1 Oscillator (5 kHz) + 4 RMS-to-DC Converters + 1 ADC Chip + 4 Protection Diodes + 1 Microcontroller + 2 Memory Chips + 1 Voltage Regulator
Energy Storage	3 x 470 µF Electrolytic Capacitors (35V) + 3 x 100 µF (16V) + 2 x 10 µF Tantalum (25V)
Isolation Rating	1500 Vrms (Inputs to Backplane)
Operating Temperature	0°C to +55°C (32°F to 131°F)
Storage Temperature	-25°C to +85°C (-13°F to 185°F)
Mounting Type	INFI 90 Rack (Single Slot)
Status Indicators	1 Green LED (Power) + 1 Green LED (Run) + 4 Green LEDs (Channel Valid) + 1 Red LED (Fault)

LVDT Input Features and Position Measurement

The ABB Bailey LPS01 accepts four independent LVDT sensors for valve position feedback. Specifically, the module generates a 5 kHz sine wave excitation for each LVDT primary coil. In addition, the module demodulates the secondary AC signals into DC position values. Moreover, the 16-bit resolution provides 65,535 discrete counts for precise positioning. Consequently, this module delivers accurate valve position feedback for turbine control systems.

Programmable Excitation and Filtering

This turbine position module features programmable excitation amplitude for different LVDT sensors. For instance, you can adjust the excitation voltage from 1 to 5 Vrms. In addition, programmable low-pass filters remove mechanical vibration noise from position signals. Moreover, the update rate of 10 ms per channel suits fast turbine response requirements. Thus, this module adapts to various valve position sensing applications.

Energy Storage and Signal Integrity

This module stores energy using eight onboard capacitors for power filtering. Specifically, three electrolytic capacitors smooth the 5 VDC supply for stable oscillator operation. In addition, three capacitors filter the 24 VDC supply for LVDT excitation circuits. Furthermore, two tantalum capacitors provide high-frequency noise suppression for analog inputs. Therefore, the ABB Bailey LPS01 maintains position accuracy during brief power interruptions.

Installation and Diagnostic Indicators

Seven LED indicators provide operational status at a glance on this module. First, a green Power LED lights when the 5 VDC backplane supply is present. Second, a green Run LED flashes during normal module operation. Third, four green Channel Valid LEDs illuminate when each LVDT channel provides a valid signal. Finally, a red Fault LED indicates excitation failure or out-of-range position. Thus, you can diagnose valve position status instantly without external tools.