As a specialist commercial electrical contractor, Micron Group is commissioned to conduct routine maintenance of electrical switchboards at numerous high-rise buildings within the Sydney CBD. One of those buildings being International Tower One, located within the iconic Barangaroo precinct.
Maintenance of main switchboards is a preventative safeguarding measure carried out routinely by qualified electrical engineers and electricians, usually annually, to identify any faults before they can develop into serious electrical issues, or worse, cause fire.
Main switchboards handle an enormous amount of energy (electrical current represented as amps) entering a building from the supply lines, and as such there can be serious consequences, or risk of fire or explosion if something goes wrong. All businesses heavily rely on electrical power, and many cannot afford a critical electrical failure, the down time to repair a fault caused by fire or component burn out far exceeds the down time required for routine electrical switchboard maintenance.
At Barangaroo International Tower One, Micron Group conducts main switchboard maintenance and service annually, this includes the following items:
Electrical Switchboard Maintenance Checklist
- Checking that all electrical connections are tightened correctly and torqued to the correct setting. Loose connections in electrical cables can lead to excessive heat and possibly fire
- Internal and external cleaning of dust, debris, and vermin – contaminants such as dust can build up and can become conductive over time, it is important to keep the switchboard clean to minimise the risk of an arc flash, explosion, or fire
- Ensuring all penetrations into the switchboard are sealed and inspecting the condition of weather seals around the switchboard covers – this helps prevent dust and debris from entering the switchboard.
- Inspection of cable insulation for signs of deterioration or damage – cable insulation must be intact in perfect order to minimise the risk of a short circuit
- Conduct thermographic scanning – thermal scanning is a great tool used by Micron Group engineers for locating faults that are not visible to the naked eye within an electrical switchboard system
- Exercising the ACB circuit breakers and ATS units
- Check for signs of corrosion, or damage, and repair as required
- Inspection of electrical switchboard metalwork and paint enamel
- Inspecting and updating all electrical switchboard labels and circuit schedules
- Checking for design changes and updating as built switchboard drawings and electrical schematics
As power to the main switchboard needs to be shut down to perform regular switchboard maintenance, there is a considerable amount of organisation required. Micron Group ensure the following is completed without compromise.
Preparing a Building for an Electrical Switchboard Maintenance Shutdown
- Working with the energy authority to shut down the building’s substation to safely isolate power to the main switchboard.
- Co-ordinating with onsite building management on the following items below:
- Performing the shutdown at a time that will have minimal impact on the operation of the building.
- Notifying tenants and building security of the shutdown as lifts and lighting will be affected.
- Working with other essential services trades to ensure that all electrical services and HVAC services return online once power is restored.
Services affected by electrical shutdowns must be clearly identified and documented, and if deemed critical, alternative temporary power is often connected using mobile generators. Diesel Generators provide the essential power required while main switchboard maintenance is safely carried out. Take for example the air conditioning services at Tower One Barangaroo: the air conditioning service was required to remain on whilst carrying out maintenance, so a generator was setup and temporary cabling installed to power these services.
Micron Group uses up to ten electricians / engineers to complete the maintenance to four large main switchboards at Tower One, this ensures the maintenance is completed methodically, quickly, and efficiently. The goal is to complete all the required maintenance items safely and effectively while ensuring the power is only off for the shortest time possible.
Procedures During the Shutdown Include:
- Isolating and locking off power from the energy authority’s substation to the main switchboard
- Testing with certified equipment at the main switchboard to confirm isolation of power
- Installing safety isolation tags and locks, locking off main electrical circuit breakers
- Removal and cleaning of all covers and panels, cables, cable lugs and busbars
- Thermographic scanning of all internal main switchboard components (while cables and busbars are still warm)
- Inspection of busbars, cables, circuit breakers and insulation
- Torque wrenches are used to ensure all connections are tightened to the specified recommended torque setting
- General inspection and cleaning inside the main switchboard
Electrical Safety – Once Switchboard Maintenance is Complete It Must Be Confirmed ‘Absolute Safe’ Before Re-Connecting Power:
- A visual inspection is carried out and technicians check each other’s work
- An insulation resistance test is carried out to confirm there are no short circuits or faults, testing strictly adheres to ASNZ:3000. Insulation resistance testing between all phases to earth and phase to phase is overseen by licensed electricians
- All covers are replaced to their correct position and secured appropriately
- Lock out tags are removed by the technicians who installed them
Once power has been restored it is important to check that all building services are restored and powered back on. Micron technicians conduct several post checks confirming and ensuring that electrical services have returned to normal, and systems are online, ensuring no circuit breakers have tripped when power was restored.
As with International Tower One Barangaroo, Micron Group recommends electrical switchboard maintenance be conducted annually. Our primary goal is to complete essential switchboard maintenance efficiently and with absolute precision, minimal disruption to the day-to-day running of the building, and to ensure the safety of the building and its occupants is maintained.