Ensuring proper Switchboard Clearances is crucial for maintaining safety and functionality in electrical installations. Switchboards must be located and installed with adequate space, ventilation, and accessibility to prevent overheating, facilitate easy maintenance, and ensure safe emergency evacuations.
Switchboard Location – General Requirements
Switchboards should be located in well-ventilated areas to prevent overheating. They must be placed in locations that allow for proper airflow. Additionally, switchboards need protection against moisture to avoid damage. There must be enough space around the switchboard for installation, future replacement of devices, and for easy operation, testing, maintenance, and repair.
Switchboard Clearances – Accessibility and Emergency Exit Facilities
Proper switchboard clearances also involve ensuring accessibility and safety in emergencies.
Unobstructed Access
Switchboards should be positioned so that neither the switchboard nor the access to it is blocked by the building’s structure or fixtures. This ensures that access is always clear.
Space Around Switchboards
There must be ample space around the switchboard on all sides to allow for safe operation and adjustments.
Emergency Exit Facilities
Switchboards must have sufficient exit routes for emergencies. Specific requirements include:
Distance Requirements: Maintain a minimum clearance of 1.0 meter from all accessible faces of a switchboard. For domestic setups, this can be reduced to 0.6 meters.
Unimpeded Space: Ensure at least 0.6 meters of unobstructed space around switchboards with doors open or switchgear fully racked-out (see Figure 2.19).
FIGURE 2.19 ACCESS TO SWITCHBOARDS—FREESTANDING SWITCHBOARD WITH SWITCHGEAR RACKED OUT
Emergency Exit Paths: For switchboards with a capacity of 800 A per phase or more than 3 meters in length, provide at least two emergency exits. An exception applies if there is a clear space of 3 meters in front of the switchboard (refer to Figure 2.24).
FIGURE 2.24 EXAMPLE OF EXCEPTION TO CLAUSE 2.10.2.2(iii) WHERE ONLY ONE EXIT PATH NEEDS TO BE PROVIDED
Access Openings: Openings or doorways should be at least 0.9 meters wide by 2.2 meters high for switchboard rooms or enclosures (see Figure 2.20).
FIGURE 2.20 ACCESS TO SWITCHBOARDS—SWITCHBOARD IN CORNER POSITION
Doors and Access:
• Switchroom doors must open outward without needing a key or tool from the switchboard side to ensure quick evacuation.
• If there are multiple doors, they should be spaced apart. Doors in narrow access areas should be capable of being secured in an open position.
• For single domestic installations, the requirements for doors and emergency exits are less stringent.
• Safety Note: Plan for multiple escape routes to handle potential arcing faults during work (see Figures 2.21, 2.22, and 2.23. Also, refer to AS/NZS 3000:2018, clause 2.10.2.2)
FIGURE 2.21 ACCESS TO SWITCHBOARDS—SWITCHBOARD WITH ONE END AGAINST WALL
FIGURE 2.22 ACCESS TO SWITCHBOARDS—SWITCHBOARD DOORS THAT OPEN INTO ACCESS WAYS OR NARROW PASSAGE WAYS
FIGURE 2.23 ACCESS TO SWITCHBOARDS—FACING SWITCHBOARDS
Location of Main Switchboard
The main switchboard has extra location requirements and must be installed according to these guidelines:
Accessibility
It should be easily accessible, located near a building entrance. Alternatively, a remote control panel for main switches can be used.
Multiple Installations
In buildings with multiple electrical installations, the main switchboard should not be within any single tenancy. This ensures that it is accessible for the entire premises.