The Alimak OSD 5 is an optional Overload Sensing Device designed to enhance the safety and operational efficiency of hoists and lifts. This system monitors the load within the car, indicating when it is fully loaded and preventing operation under overload conditions.

Function Description

The OSD 5 system integrates load cells into the pull rods that connect the machinery to the car structure. These load cells measure the weight within the car, and their signals are transmitted to the OSD 5 amplifier, typically located in the M-panel. When the rated load is exceeded, the control circuit of the hoist is automatically switched off to prevent its use, and a red LED light is activated to indicate the overload condition. For hoists equipped with an ALC (Alimak Lift Control) system, an overload will trigger fault code F4 on the display.

The OSD 5 offers various operational modes and functions:

Calibration Mode – System Setup: This mode allows for the configuration of system parameters, including payload and alarm limits. Users can adjust settings such as Payload (400 kg - 30000 kg), Overload (R1, 100-120% of payload), Full load (R2, 30-100% of payload), Underload (R3, absolute values not less than hysteresis), and Hysteresis (Hst, not less than 75 kg and not more than 10% of payload, or bigger than 80 kg). Load Calibration can be set between 50-120%. The system setup is accessed by pressing "Prog." and "Zero" buttons, then using "Cal." to navigate parameters and "Zero" and "Load" to adjust values. All changed parameters must be tabbed through before returning to the Weight display to ensure they are stored.
Calibration Mode – Zero Calibration: This procedure establishes the "empty car" weight. It is initiated by pressing "Prog." and "Zero" buttons, then selecting "Zero" from the menu. The lift/hoist must be empty (no load). Pressing "Cal." starts a countdown from 10 to 1, allowing the operator to exit the car. Upon completion, the zero point is automatically calibrated and stored.
Calibration Mode – Load Calibration: This procedure calibrates the system with a known weight. It is initiated by pressing "Prog." and "Zero" buttons, then selecting "Load" from the menu. A calibration weight, ideally 100% of the payload (but at least 50%), must be placed in the car. The stored weight value is adjusted to match the calibration weight using "Zero" and "Load" buttons. Similar to zero calibration, pressing "Cal." starts a countdown, allowing the operator to exit the car. The calibration weight is automatically stored upon completion.
Calibration Mode – Load Calibration with Default Values: This is an automatic calibration method that uses predefined values for specific Alimak models (e.g., Scando 650, Scando 450, 6-ton load cell). This method sets both load and zero values. It requires the car to be empty.
Work Mode – View Current System Parameters: This mode allows operators to view the stored system parameters, such as Elevator Capacity, Relay 1 and 2 Alarm capacities, and Reset values. Parameters marked with an asterisk can be altered in "Cal. mode."
Work Mode – System Test and Zero Functions: This mode allows for testing inputs and outputs. Pressing and holding "Prog." displays input and output states. The "Load" button activates a self-diagnostic system test, which sequences through the instrument's hardware components to ensure operational status. The display also shows the software version (S 1.xx) and indicates whether the device is wired to ALC II CAN interface ("CAn") or relay control ("RELAY").
Failsafe Mode: This function is for situations of over or under load, such as running against buffer springs or during a drop test. Activated by pressing the "Zero" button for 5 seconds, it displays "InSP" for inspection mode or "- - ---" otherwise. If connected to CAN, five trips are allowed; otherwise, a maximum of two trips are possible.
Relay Function: The OSD 5 has two digital inputs (+24VDC). DI1 is activated when the lift/hoist is stationary and brakes are engaged. DI2 is activated when doors are closed, enabling measurement and potential operation based on weight. After a power failure, 10% extra weight is approved for the first trip, indicated by synchronized flashing dots on the display. Subsequent trips show out-of-sync flashing dots.
Trailing Cable Compensation: This function compensates for the weight of the trailing cable. It is activated by setting a function bit and performing a Zero Calibration at the bottom floor, then traveling to the highest possible point and performing another Zero Calibration. Cable weight can be set between 0.9 - 4.8 kg/m, with a maximum compensation of 250 kg per load cell or 10 kg/m.
Verification: In "Work mode," pressing the "Zero" button displays the difference between load cells. Pressing "Prog." followed by "Zero" displays the temperature.
Extra Functions (Func0-Func8): These functions offer specialized behaviors:
- Func0 (Default): Normal full load and overload function.
- Func1 (Bit 0): For permanent lifts with special requirements. Relay 2 activates for 5 seconds at full load. Payload activates Relay 1. Overload triggers ALCII alarm F4.
- Func2 (Bit 1): For lifts with floor sensors, using input instead of weight. Input 2:1 for full load, 2:2 for overload.
- Func4 (Bit 2): For special lifts where an empty car is heavy relative to payload. Deactivates alarms for 6.1-6.2 errors (software v1.08) or 1.x and 6.x errors (software v1.09 and higher).
- Func8 (Bit 3): For lifts with low payload and high lift height, enabling trailing cable compensation.
- Multiple functions can be activated by adding their binary bit values.

Important Technical Specifications

Payload Range: 400 kg - 30000 kg
Overload (R1) Setting: 100 – 120 % of payload
Full Load (R2) Setting: 30 – 100 % of payload
Underload (R3) Setting: Absolute values cannot be less than hysteresis (Hst)
Hysteresis (Hst) Setting: Not less than 75 kg and not more than 10 % of payload, or bigger than 80 kg
Load Calibration Range: 50 – 120 % of rated load
Trailing Cable Compensation: 0.9 - 4.8 kg/m, max 250 kg per load cell or 10 kg/m.
Software Version: Valid mainly for OSD software version OSD-5 1.09 and later versions. ALCII functionality requires software version 3.50 or later.
Digital Inputs: 2 x +24VDC for relay function.
Load Cell Connection: Uses 4-wire connection for +Exc, -Exc, +Signal, -Signal, and Screen.
- EXC + = RED (RD - BU ~ 410 Ohm)
- SIG + = GREEN (GN - YE ~ 350 Ohm)
- EXC - = BLUE
- SIG - = YELLOW
Supply Voltage: 24 VDC.
Display: LED display for weight, menu navigation, and error codes.
Relay Outputs: Relay 1 (Overload), Relay 2 (Full load).

Usage Features

Intuitive Interface: The front panel features "Prog.", "Cal.", "Load", and "Zero" buttons for navigation and adjustment of settings.
Visual Indicators: A red LED light indicates overload. The display shows current weight, system parameters, and error codes. Dots on the display provide run indications and status for extra weight trips.
Error Codes: A comprehensive list of error codes (Err 1.1 to Err 9.3) helps diagnose issues such as abnormal load cell values, reversed pin positions, communication failures, ID tag errors, programming errors, A/D converter errors, calibration issues, heavy car weight, wrong inclination, load cell constant-value ratio errors, ROM checksum errors, serial number errors, and trailing cable compensation errors.
Production Mode Testing: The display can show "tESt" if the device is in production mode for testing. This can be removed by performing a Zero Calibration followed by a Load Calibration.
Software Update Capability: Software can be downloaded from the A3 website for ALC II systems (version 3.50 or later). This process is for certified personnel only and involves specific steps for booting and restarting the ALC II.

Maintenance Features

Self-Diagnostic System Test: The "System test" function allows for quick verification of the instrument's hardware components.
Debug Information: Accessing debug information (by pressing "Cal" then "SYS", "R1", "R2", "R3", "Hyst", or "Func" and then "Load" or "Zero") provides detailed insights into current system parameters, load cell values, compensation values, floor positions, current and programmed positions, distance between zero calibrations, and current value in % from R2. This is crucial for troubleshooting and system monitoring.
Calibration Procedures: Regular Zero and Load Calibrations ensure accurate weight measurement and system performance.
Trailing Cable Compensation Calibration: This specific calibration helps maintain accuracy in systems with varying cable weights.
Error Code Diagnostics: The detailed error codes guide technicians in identifying and resolving specific issues, from wiring problems to programming errors.
Software Updates: The ability to update software ensures the device operates with the latest features and bug fixes, enhancing long-term reliability and performance.

Alimak OSD 5 - Page 3

Table of Contents