OTIS LCB II (Limited Capacity Board II) is a microprocessor-based controller board used in OTIS MCS-220 elevator systems. This guide provides a verified overview of its technical specifications, diagnostic indicators, and critical fault codes based on official field component documentation. 1. Hardware Overview & Specifications The LCB II board (part number GDA 21240 D
for the current version) contains an Intel 8088 microprocessor and is divided into analog and digital sections. Power Protection : The board is protected by Fuse F1 (4A)
, which covers the 24Vdc supply. If F1 blows, the system loses 30Vdc tension, disabling calls and sensors. Compatibility
: It supports various drive types, including AC 2-speed, Hydraulic, and Variable Frequency (LVF/LSVF).
: Features dedicated LEDs for real-time status and a port for the Service Tool (SVT) used for advanced diagnostics. 2. Diagnostic LED Indicators
Technicians can perform a visual check of the board's health by observing the following LEDs: Normal Status Board Power Supply : 22 Vac power is present from the transformer. Brake Situation : Brake coil is energized. Group & Phase Relay : Normal power phases (Relay J OK). Intermittent : Phase inversion or missing phase. Operational Status Indicates the elevator is in a normal operational state. 3. Critical Fault Codes & Troubleshooting otis lcb ii manual verified
Faults are logged in the LCB II service tool under the "Event Logging" menu. Common codes include: Operational Errors 0100 (OpMode)
: OCSS cannot operate due to a driver failure (BR or NR failure). 0102 (OpMmode DTC) : Door cannot close within the set time. 0103 (DTO) : Door cannot fully open within the set time. Motion & Safety Errors 0202 / 0203 (DFC)
: The ES (Emergency Stop) signal activated while the car was running fast or slow. 0204 (TCI/ERO) : The inspection or emergency recall switch is activated. 0224 (1-Relay)
: Indicates a missing phase or that the TCBC/GECB board failed to start. Communication Errors 0400 (RSL Parity)
: Two remote stations are sharing the same serial line address. 0500 (RNG 1 msg) : Data error on the elevator serial lines. 4. Key Service Tool Commands OTIS Service Tool Guide , you can interact with the board using these functions: : Sends the car to the bottom or top terminal floor. : Disables door opening for testing. : Disables hall calls. Clear "LV ERROR" : On CVF controls, press the Blue Key + 5 OTIS LCB II (Limited Capacity Board II) is
on the URM to clear drive-related low voltage errors after a fuse replacement. For detailed parameter adjustment, refer to the MCS - LCB II List of Parameters
which outlines settings for door movement times and position indicators. for a particular drive type, such as LSVF or Hydraulic OTIS Elevator LCB-2 Fault Codes Guide | PDF - Scribd
Under ASME A17.1-2019/B44-19, Section 8.11 mandates that “maintenance and repair procedures shall be performed in accordance with the manufacturer’s instructions.” Using an unverified manual exposes a building owner or contractor to:
Drawing from verified field experience and manual specifications, here are solutions to the three most common LCB II issues:
The OTIS LCB II (Logic Control Board II) is one of the most widely deployed elevator control boards in history, found in hundreds of thousands of OTIS 211, 311, and 411 MRL (Machine Room-Less) and geared traction elevators manufactured from the mid-1990s to the late 2000s. It is a second-generation microprocessor-based controller that replaced the LCB I, offering improved serial communication (RSL5), expanded input/output capacity via remote stations (RS-5/RB-5), and better diagnostic capabilities via a handheld Service Tool (SVT). Code of Federal Regulations (CFR) – Elevators Under
When a technician or a maintenance log uses the phrase "LCB II Manual Verified," it is not merely a checkbox — it is a procedural declaration with legal, operational, and safety implications.
P-332-04 Rev C (03/2005).If you have eApps access, input the manual’s ID number. The system will confirm:
The elevator accelerates roughly or cannot find the floor level.
| Component | Label | Function | |-----------|-------|----------| | Main CPU | U1 | 68HC11E9 (mask ROM version) | | EEPROM | U6 | 93C46 (stores parameters & faults) | | Watchdog timer | U4 | DS1232 – resets CPU if program stalls | | Power LED | DS1 | Solid = 5V logic supply OK | | Run LED | DS2 | Blinking ~1Hz = normal operation | | Fault LED | DS3 | Steady or coded blink = fault active | | RSL connector | J5 | 2-wire serial to hall/car fixtures | | Door operator | J10 | 0–10V analog position command |
✅ Verified: The RSL bus must be terminated with a 120Ω resistor at the last device. Missing termination causes intermittent “COMM LOSS” faults.
