Description
1. Product Overview
Model: UT150-2
Brand: ALSTOMCompatible System: Exclusively matched with ALSTOM Alspa™ series distributed control system. It serves as the standard Local Operator Unit (LOU) for turbine ETS trip protection systems and generator set drive control architectures, and is a core EOL discontinued maintenance spare part.
Product Definition: This device is an on-site human-machine interaction and local instruction processing module, acting as a supplementary local operation terminal for the central control DCS system. It supports unit start/stop, operation mode switching, process parameter viewing and modification, fault alarm acknowledgement & reset, as well as local storage of operation events beside the equipment cabinet. Equipped with dual redundant communication links and hardware self-test functions, it also implements local logic judgment for protection signals including turbine overspeed, shaft vibration and axial displacement. Complying with IEC 61508 SIL3 functional safety level, it is the core front-end hardware for on-site monitoring and safety operation of thermal power steam turbine generator units, hydropower water turbine units and large industrial drive turbines.
2. Hardware Structure & Six Functional Units
2.1 Backlit LCD Display & Membrane Keypad Operation Unit
It adopts a 2-line × 20-character monochrome backlit LCD display with good visibility in low-brightness computer room environments. The front panel integrates an integrated membrane keypad matrix including function switching keys, numeric input keys and page-up/down navigation keys with clearly hierarchical menus. It can retrieve all measurement point data such as unit rotational speed, temperature, oil pressure, valve position, protection setpoints and fault history page by page. It supports manual on-site issuance of start, stop and emergency trip commands to realize independent local control of individual equipment without relying on the central control system.
2.2 Dual Isolated RS485 Redundant Communication Unit
The board carries two mutually galvanically isolated RS485 communication interfaces adopting the standard Modbus-RTU protocol; baud rates of 9600/19200/38400bps can be configured on site. The primary and backup links operate in hot redundancy mode and automatically switch to the backup channel seamlessly within 1 second once the main bus line is broken, avoiding loss of operation control and data transmission interruption. It can connect to the rack backplane bus to perform bidirectional data interaction with Alspa main control CPU, protection modules and remote upper systems, and supports multi-module networking topology construction.
2.3 Non-Volatile Event & Fault Storage Unit
An on-chip EEPROM power-off memory chip is integrated to cyclically store timestamped operation logs, protection action records, communication anomaly alarms and parameter modification records. Data is permanently retained after power loss without relying on archiving by the upper system. It can store no less than 300 sequential events to facilitate review of operation procedures and root causes of fault triggers after unit shutdown due to accidents. It supports separate reset of a single alarm and one-key clearing of all alarms in batch.
2.4 Local Protection Logic & Hardware Fast Trip Unit
It contains two independent dual-channel arithmetic cores adopting a 2-out-of-2 (2oo2) voting architecture; a trip command will only be output when fault conditions are judged by both channels simultaneously to prevent spurious tripping caused by single-circuit single-point faults. It collects hard contact signals from speed probes, vibration sensors and temperature switches in real time, and outputs trip drive signals within milliseconds once over-limit conditions are detected. A hard-wired safety protection loop is formed independent of main control software to prevent loss of emergency shutdown capability of the unit resulting from main control crash or bus disconnection.
2.5 Wide-Voltage Regulated Power Supply & Multi-Level Protection Unit
Rated input power supply is DC 24V with an allowable input voltage fluctuation of ±10%. The internal circuit integrates EMI power filtering, reverse polarity protection, overcurrent fuse and TVS surge clamping circuits. The mainboard will not be burnt down by instantaneous grid spikes or reversed wiring polarity. The power supply circuit is galvanically isolated from communication and signal loops to prevent supply interference from coupling into the bus and causing system disorder, with the overall power consumption lower than 10W.
2.6 Panel Embedded Mounting & Industrial Three-Proof Reinforcement Unit
It adopts standard cabinet panel cutout embedded installation. The front operation panel reaches IP65 ingress protection rating against water splash and dust accumulation. The entire PCB is coated with conformal coating for moisture proofing, anti-corrosion and salt spray resistance. The device features a fanless enclosed passive heat dissipation structure with no mechanical wearing parts. Key chips on the circuit board are designed with sufficient heat dissipation margin to withstand long-term operation under harsh conditions including high temperature inside sealed cabinets and low-frequency vibration from the turbine unit body.
3. Detailed Technical Specifications
(1) Core Function & Interaction Parameters
| Item | Specification |
|---|---|
| Product Model | UT150-2 Local Operator Unit (LOU) |
| Compatible System | ALSTOM Alspa™ DCS Control System, Turbine ETS Protection System |
| Display Specification | 2×20 character monochrome backlit LCD |
| Operation Input | Integrated membrane function & numeric keypad panel |
| Communication Configuration | Dual isolated RS485, Modbus-RTU, automatic redundant switching |
| Event Storage | Local EEPROM storage of ≥300 timestamped event records, data retained after power off |
| Safety Architecture | Dual-core 2oo2 voting logic, SIL3 functional safety certification |
| Core Functions | Local start/stop, parameter setting, alarm reset, protection interlock, fault query |
| Panel Protection | Front panel IP65, rear wiring compartment IP20 |
(2) Electrical Power Supply & Bus Parameters
- Rated Operating Power Supply: DC 24V, voltage range 21.6~26.4V
- Typical Overall Power Consumption: ＜10W
- Communication Terminals: Tool-free pluggable Phoenix terminals with push-in quick wiring
- Backplane Compatibility: Fits standard Alspa rack backplane slots and supports centralized rack power supply
- Hot Swap Note: Hot plugging of this module and communication wiring terminals while the cabinet is powered on is strictly prohibited
(3) Environmental Applicable Parameters
- Standard Operating Temperature: -10℃ ~ +60℃
- Storage & Transportation Temperature: -20℃ ~ +70℃
- Relative Humidity: 5%~95% RH, non-condensing, free of strong corrosive gas and salt fog condensation
(4) Mechanical Installation Dimensions
- Cabinet Cutout Size: 146mm (W) × 74mm (H)
- Overall External Dimension: 160mm (W) × 88mm (H) × 55mm (D)
- Mounting Method: Clip-on embedded cabinet panel mounting, no rear screws required for fastening
- Net Weight: Approx. 0.42kg
- Housing Material: High-strength flame-retardant engineering plastic front frame + metal shielding backplate
4. Product Functions & Technical Advantages
Redundant Dual-Bus Architecture Eliminates Single-Point Disconnection Risk for Local Operation
The two communication links operate in hot backup mode and switch over seamlessly if one line ages or breaks down. On-site maintenance personnel will not be unable to perform local shutdown operations due to a single cable fault, greatly improving the reliability of on-site emergency disposal for the unit.
Independent Hardware Logic Protection Loop Provides Backup Protection Independent of Main Control Software
Trip signals are directly output by on-board hardware circuits. Even if the entire DCS main control program crashes and the network is completely disconnected, this module can still execute emergency tripping upon overspeed and excessive vibration, forming the final hardware safety barrier for the unit.
Hierarchical Permission Control for Local Parameters Prevents Human Misoperation
A two-level password lock is configured for operator view-only access and administrator parameter modification access. Critical parameters such as grid paralleling setpoints and protection trip thresholds can only be modified with authorized passwords to avoid grid impact and equipment faults caused by incorrect parameter changes by inspection staff.
Independent Local Event Archiving Enables Fault Tracing Without Relying on Upper System
Fault and operation records are stored in the module's local memory chip. Historical data can still be retrieved after the upper system goes offline or shuts down. Troubleshooting trip causes does not depend on log files from the central control server, shortening fault analysis time.
IP65 Front Panel Protection Allows Direct Installation in On-Site Outdoor Control Cabinets
The front panel reaches dustproof and waterproof grade suitable for direct installation in on-site cabinets without additional protective covers. It is ideal for on-site cabinets in turbine halls with high moisture and dust, delivering a compact and tidy cabinet layout.
Standard Modular Design Supports Direct Drop-In Replacement of Same-Series Spare Parts
Following unified hardware specifications of the Alspa platform, the same model spare part can be put into service directly after disassembly and installation without reconfiguring rack backplane settings or program configurations, enabling module replacement within short unit outage windows at power plants.
5. Application Scenarios
Thermal Power Generation Industry
Local operation panel for turbine generator unit ETS emergency trip systems and Alspa DCS control systems, used for collecting protection signals including turbine rotational speed, axial displacement and bearing vibration, as well as local unit start/stop and fault acknowledgement & reset.
Hydropower Energy Industry
On-site HMI terminal for water turbine governor systems and inlet valve control units, supporting gate opening adjustment, unit grid paralleling operation and local triggering of overspeed protection.
Petrochemical Industry
On-site monitoring and operation unit for large process drive turbines and cracking gas compressor sets, enabling on-site viewing of process parameters and reset of interlock faults, meeting on-site control requirements for explosion-proof chemical plant areas.
