To strengthen the management of control systems and ensure the safe, stable operation of instrumentation control systems such as DCS (Distributed Control System), SIS (Safety Instrumented System), and PLC (Programmable Logic Controller), this management policy is established. It aims to improve the environment of the control cabinet room, facilitate system maintenance, and prevent accidents effectively.
I. Environmental Management of Control Cabinet Rooms
Cleanliness and Housekeeping
The control cabinet room must be kept clean and tidy. Regular cleaning and inspection shall be carried out to eliminate dust and debris.Sealed Enclosures
All control cabinets must remain properly closed to minimize dust ingress.Temperature and Humidity Control
Temperature and humidity shall be strictly regulated in accordance with the SH/T3006-2024 Specification for Petrochemical Control Room Design.Room temperature range: 18℃ to 28℃, with a temperature change rate not exceeding 5℃/h.
Relative humidity range: 30% to 70%, with a humidity change rate not exceeding 6%/h.
Condensation must be strictly avoided at all times.
Lighting Requirements
All lighting fixtures shall be functional and provide adequate illumination to meet work needs.Storage Restrictions
No miscellaneous items or hazardous materials (e.g., flammable or explosive substances) shall be stored in the control cabinet room.Noise Control
Maximum permissible noise in cabinet room: 70 dB(A)
Maximum permissible noise at the engineer station: 60 dB(A)
Electromagnetic and Mechanical Interference Prevention
During plant operation, there shall be no obvious magnetic fields or strong mechanical vibrations within the cabinets. Equipment generating electromagnetic interference is strictly prohibited.Static Electricity Protection
Personnel entering the cabinet room must wear anti-static clothing and use grounding wristbands or anti-static footwear as needed.
II. Work Management Within Control Cabinet Rooms
Access Control
During plant operation, only authorized instrument maintenance personnel may enter the control cabinet room or engineer/operator stations. Unauthorized access is strictly prohibited.Personnel Conduct
Personnel must wear clean attire, maintain cleanliness of the environment and equipment, avoid contaminating surfaces, and restore all items to their original position after work.Work Discipline
Any unrelated activity or personal behavior is strictly forbidden inside the cabinet room.Prohibited Equipment Use
Use of equipment such as welding machines, electric drills, or any other high-EMI devices is prohibited within the cabinet room.Wireless Communication Restrictions
Operation of wireless communication devices (e.g., walkie-talkies, mobile phones) is prohibited within a 2-meter radius of the control cabinets, engineer station, or operator station.Personnel Monitoring Requirement
When performing work at the engineer station, maintenance personnel must be accompanied by at least one other qualified individual. Solo work is not allowed.
III. Control System Management Regulations
System Configuration Changes
Any modification to the control system (e.g., alarm settings, ranges, graphic screens) must be reviewed and approved by process engineering personnel.A configuration change log must be maintained.
Major control strategy changes require submission of a Control Strategy Change Request Form, with approval from relevant leadership.
Password Management
Passwords for servers, engineer stations, and operator stations shall be maintained by designated personnel.
Operators are not permitted to log in using engineer-level credentials.
Unauthorized Power Use Prohibited
Use of dedicated power strips under operator consoles without prior approval is prohibited.Fault and Maintenance Records
After any fault rectification or system repair, complete and accurate troubleshooting and maintenance records must be submitted.Computer Operation Protocol
Before shutting down the engineer station, the file system must be verified.
Upon startup, no operations should be conducted for 10–15 minutes, and the SOE (Sequence of Events) and alarm panels must be confirmed to be running.
Virus Prevention and Backup Policy
Before performing data backup, all USB drives or external hard disks must be fully formatted to prevent virus transmission.
Backups should be performed routinely and securely stored, ensuring system recovery is feasible in case of failure.
Commissioning of New or Modified Systems
Any newly built, modified, expanded, or reactivated control systems must undergo thorough inspection and confirmation prior to use.
IV. Control System Maintenance and Inspection Policy
Routine Maintenance Responsibility
Instrument maintenance staff shall perform regular maintenance in accordance with the system configuration and operational status, ensuring safe and stable operation.Scope of Maintenance Tasks
Maintenance tasks should include, but are not limited to:A. Environment Cleaning:
Clean the cabinet room, remove dust from cabinet surfaces, clean operator consoles, filters, fans, fire extinguishers, and engineer/operator station computers.
B. Power Supply and Grounding Checks:
Inspect power module indicators for alarms.
Check for unusual sounds or overheating.
Verify UPS operation, battery status, and leakage.
Confirm all grounding terminals are secure and meet requirements.
C. System Health Monitoring:
Check status LEDs on controllers, I/O modules, communication cards, HUBs A/B.
Look for overheating in safety barriers and relays.
Listen for abnormal fan noises in control and operator stations.
D. Cable and Animal Prevention Checks:
Ensure cable entry points are sealed.
Inspect all anti-rodent measures for integrity.
E. Configuration Backup:
Conduct regular system configuration backups.
Verify validity and timeliness of all backup files.
Maintenance Recordkeeping
All maintenance logs must be clearly written, well-organized, and securely archived. Any detected issues must be promptly recorded in a defect log and addressed immediately by qualified personnel.