Electrical Instrument Installation? Follow These Best Practices

Electrical Instrument Installation: Preparation, Procedures, and Principles

Electrical instruments are crucial devices for monitoring various technical parameters of electrical equipment. In recent years, with the deepening of reform and opening-up, electrical instrumentation engineering has driven rapid industrial development and plays a vital role in promoting industrial transformation.

Currently, technological upgrading has become a key initiative for enterprise revitalization. Whether it involves process technology upgrades or instrumentation upgrades, close cooperation with instrumentation specialists is required. Therefore, instrument operators need not only knowledge and skills for daily maintenance but also expertise in the selection, installation, and commissioning of process measurement and control systems to effectively implement these tasks.

1. Preparations Before Electrical Instrument Installation

To ensure measurement accuracy and reliability, electrical instruments must meet the following requirements: accuracy must comply with specified standards; sufficient anti-interference capability is required so that measurement errors do not vary significantly due to external factors; the instrument’s own power consumption should be as low as possible to avoid large errors when measuring low-power electrical equipment; adequate insulation resistance and dielectric strength are essential for safe operation; and the instrument should have a clear, easy-to-read display with clear, distinct, and uniformly marked scales.

Additionally, before installation and construction, each component of the instrument installation design drawings must be analyzed in detail, including the design specifications, instrument equipment summary table, instrument list, instrument component summary table, instrument layout drawings, etc.

A thorough review and analysis of these drawings ensures that installed instruments and components meet all specified requirements and quality standards. This facilitates post-installation testing and trial operation and helps prevent system failures caused by individual component issues after installation.

2. Steps for Electrical Instrument Installation

To ensure smooth execution of electrical instrument installation projects, construction steps must be reasonably planned. Instrument installation is a long-term project that begins during the civil construction phase, requiring coordination with civil engineering teams to clearly define the location, quantity, elevation, coordinates, and dimensions of embedded parts and reserved openings. The installation then proceeds as follows:

First, fabricate the base channel steel for instrument panels. This step can be skipped if the purchased instrument panel includes a pre-fabricated base frame. Next, install instrument panels and control consoles. Simultaneously, verify the number and location of civil engineering reserved openings and embedded parts, and confirm the position and method for routing pipes into the control room.

After on-site instruments are installed, protective enclosures (such as instrument protection boxes) should be installed promptly to prevent damage from other construction activities. Mounting brackets for instrument enclosures should also be installed. A "two-step" approach can be adopted: while wiring personnel install cables and pneumatic tubing to the already-installed instruments, others install protective enclosures—this improves efficiency for wiring and piping work.

Once all on-site work is completed, instrument piping should be blown out and pressure-tested, constituting the first calibration of the installation. Trial operation of the construction project should also begin. During this phase, system refinement is achieved through calibration and debugging.

At this point, installation, calibration, and debugging are essentially complete. The system should be periodically inspected during later use to ensure stable operation.

3. Basic Principles of Electrical Instrument Installation

Ten fundamental principles must be followed during electrical instrument installation:

• Warning signs on any electrical equipment must not be moved by unauthorized personnel.

• If insulation of electrical equipment or wiring is damaged, live parts are exposed, or abnormal conditions are detected during operation, power must be immediately cut off, work stopped, and repairs completed before resuming use.

• When bending conduit, select the appropriate bender based on pipe diameter; avoid excessive force. When threading wires, keep your head away from pipe ends to prevent injury from wire ends.

• When cutting grooves or holes in structures, wear gloves and protective goggles, and take care to prevent falling debris from injuring people.

• When laying cables, wear gloves and necessary protective gear to avoid skin poisoning.

• Installation, assembly, and moving of instrument panels must be directed by a designated person to ensure coordination and prevent accidents.

• When installing instruments on panels, personnel on both front and back sides must coordinate closely to prevent instruments from falling and damaging equipment or injuring personnel.

• Instruments containing liquid standard cells must not be inverted.

• Equipment or wiring that may interfere with instrument sensitivity must not be placed near instrument rooms, nor should chemical substances that emit corrosive gases be stored there.

• Tightening or removing instrument fittings on pressurized process equipment or piping is prohibited. If necessary, appropriate safety measures must be taken.

4. Project Handover and Acceptance

Upon project completion, a trial operation is conducted in three phases: individual testing, integrated testing, and design-condition testing.

Individual testing involves trial operation of individual electrical instruments, primarily testing indicating instruments. Detection is performed by operating measurement instruments, instrument tubing, and control room controls.

Integrated testing follows successful individual testing. The entire system is run using water instead of process material to verify normal operation of display, control, and other functions. After successful integrated testing, formal trial operation begins, using actual production processes to test the electrical instruments. This testing must be jointly conducted by the construction unit and the client. Upon successful operation, the project is formally handed over through the signing of completion documents.

5. Conclusion

Electrical instrument installation and commissioning is a complex project that must begin early in the plant construction process. It requires production departments to specify operational requirements, engineering departments to design, construction units to execute, and civil engineering teams to cooperate.

Therefore, detailed design input and requirements from relevant departments are essential before construction begins, and these must align with production process requirements. Engineering design must strictly reflect the enterprise’s actual production conditions, and only through rigorous construction can a qualified, production-adapted electrical instrumentation system be successfully installed.