A switchgear is a crucial component in electrical systems, serving as a protective device, which controls and isolates electrical equipment. So, proper installation is key for the safety and reliability of electrical systems as well as personnel. This article delves into aspects of switchgear installation including key considerations, personnel responsibilities, installation procedure, as well as a comprehensive checklist.
Considerations Before Switchgear Installation
There are several factors that require attention before commencing the installation of a switchgear in a facility. Some of these factors include:
- System Design Analysis: Before starting the installation, thoroughly analyze the electrical system design. Also, the specifications of the switchgear must align with the system requirements. There should be provision of proper earthing connection, and verification of all components such as relays, busbar sizes, meters, circuit breakers, fuses, etc.
- Clearance and Accessibility: Enduse adequate clearances around the switchgear for ventilation and accessibility. Clearances must include compliance with safety standards as well as Internationel Electric Code and local regulations. Of particular concern is where cables enter into the switchgear – be it bottom or top entry. Ensure cut-outs are properly sized.
- Environmental Conditions: Evaluate the environmental conditions at the installation site. Moreover, switchgear installation should be in areas with minimal dust, humidity, and corrosive gasses to prevent deterioration. If indoors, the room needs proper air conditioning and should be dry at all times. Outdoor switchgear should have an enclosure suitable to withstand prevailing weather conditions.
- Electromagnetic Compatibility: Consider electromagnetic compatibility to prevent interference with other electrical equipment. It could be necessary to install shielding measures.
- Cable Routing: Plan the cable routing to minimize electromagnetic interference. Also, ensure proper segregation between control and power cabling. When routing cables, follow specifications in terms of cable radius by the manufacturer. All cable entries and other openings of the room or floor must be sealed with proper sealant.
Switchgear Installation Procedure
The installation procedure varies from company to company and whether the installation occurs in an intermediate facility or at the final destination. Below are general guidelines – manufacturers will provide specific installation guidelines.
- Site Preparation: Ensure that bases, the e-house structure, cable trenches, and holes for bolts are match the manufacturer’s specifications. Provide adequate lighting at all times during and after installation.
- Receiving and Handling: Handle switchgear components with care during transportation and unloading. Use an approved lifting method. Cover and store the equipment in a dry place.
- Assembly and Interconnection: Follow the manufacturer’s guidelines for assembling and interconnecting switchgear components. Also, pay attention to torque specifications for bolted connections, and ensure proper grounding to avoid electrical shocks and to provide a path for fault currents. Cable pulling, termination, and crimping should be according to specifications. All installations shall follow applicable electrical regulations such as IEC 61439 and IEC 61936-1.
- Circuit Breaker Installation: Follow the precise procedure for the installation of switchgear circuit breakers. In addition, proper alignment, mounting, and connection are necessary.
- Control Wiring: Control wiring should follow wiring diagrams from the manufacturer, using color-coded wires and secure terminations.
- Functional Testing: Conduct functional tests to verify the correct operation of all switchgear components. These include tripping and closing operations and checking control and protection features.
- Safety Measures: Implement safety measures throughout the installation process such as the use of PPE, adhering to lockout procedures, and utilizing the right tools for each task.
Personnel Responsibilities
Personnel responsibilities vary from facility to facility, but all facilities and projects require a coordinated effort across multiple people to ensure safe switchgear installation. Typical personnel often involve the following:
- Project Manager: Ensures that work progresses according to plan and that the necessary equipment is available in good condition. Also, collaborates with the Safety Personnel and QA/QC Inspector to establish and follow safety and quality control measures respectively.
- Project Engineer: Interprets specifications, advises on cable sizing requirements to connect switchgear.
- Designer: Produces drawings and often a 3D model that shows the switchgear line-up and its position on the front relative to major beams and cross members.
- Fabricator: Ensures the placement of the switchgear as per drawings and requirements.
- QA/QC Inspector: Monitors execution of work to ensure they follow approved shop drawings and project specifications. This may require an engineering degree, but typically comes from a fabrication background.
Switchgear Installation Checklist
Although the installation procedure for a switchgear may vary depending on the manufacturer, there are key steps to take before, during, and after installation.
Pre-Installation Checklist
It is necessary to accomplish the following steps before commencing installation:
- Determine the suitability of egress points for switchgear to be brought into the e-house.
- Ensure adequate clearance and accessibility inside the e-house
- Verify that installation is compatible with the planned entry point of cabling (either top mount or bottom mount)
Installation Procedure Checklist
- Set the switchgear in place.
- Bolt shipping splits together.
- Bus bar installation.
Note: the subsequent steps will only be performed once the switchgear arrives at its final destination.
- Bring the cables into the e-house/switchgear.
- If applicable, prepare the cabling for termination and terminate.
- Conduct any SATs (Site Acceptance Tests).
- Energize the switchgear as per established standards.
Post-Installation Checklist
- Verify proper quality checks are confirmed.
- Transfer any redlines to designers or project engineers.
- Notate the work performed as per company guidelines.