APTP Articles

No More Manual ACB Racking – A Game Changer in Electrical Safety!

NHP’s TemRack iR enables remote racking of the Terasaki TemPower 2 AR Air Circuit Breaker (ACB). This automated racking function permits safe isolation of the ACB with zero physical interaction between personnel and the ACB.

Arc faults are serious events where a large amount of electrical energy is explosively released, which could result in serious burns or death of operators in the area. Additionally, they can cause significant damage to switchgear, conductors, switchboards and installations, which results in costly downtime and repairs.

The time spent in a potentially dangerous area can be minimised by utilising common accessories for switchgear which facilitate remote operation, such as motor operators and open/close coils. There are also methods available to complete the racking of circuit breakers remotely. These allow the operator to be away from the switchroom when switching and racking operations are occurring.

Each year there are between 6 and 11 incidents involving arc faults in Australia. Injuries to workers range from serious burns to death. (Australian Institute of Health & Safety, 2019.)

The hierarchy of controls is used to mitigate risks in the workplace, ranking the risks from the least effective to the most effective in relation to their level of protection and reliability. At the bottom rung of the hierarchy is PPE which is the ‘least effective’, through administrative controls, engineering controls, isolation, substitution, followed by elimination as the most effective means of control. 

The most likely time for an arc fault to occur in a switchroom is during electrical and mechanical operations, such as switching, isolation and racking of circuit breakers. It is common practice in the industry to use personal protective equipment (PPE) for operator protection during these operations, however it is more effective to isolate the operator entirely from the arc fault hazard. Isolation involves personnel being separated from the energised electrical equipment and conductors. 

NHP’s TemRack iR is a fully integrated automated racking device, which enables remote racking of the Terasaki TemPower 2 AR ACB body in and out of its associated carriage. The automated racking function permits safe isolation of the ACB with zero physical interaction between personnel and the ACB, thereby reducing the risk of exposure to explosive arc fault events and high incident energy.

The TemRack iR’s mechanical interlocks and safety functions integrate seamlessly with the ACB, with the ACB’s functionality remaining unaffected. Similarly, your electrical protection methodology/system onsite remains unaffected.

The TemRack iR features integrated digital I/O for control and feedback, allowing the operator to remotely rack the ACBs in or out while the operator is located outside the switch room. Remote control can be performed via a local control station or other remote methods utilising the integrated I/O on your automation system. Where ACBs are fitted with open/closed coils, the remote operation of the ACB can also be performed as a further risk mitigation strategy.

The TemRack iR device can be fitted as part of a new ACB build or retrofitted to an existing Terasaki TemPower 2 AR ACB by NHP’s Service and Solutions Team.

TemRack iR integrated racking devices will help you to significantly improve personnel safety at your plant by separating personnel from the energised electrical equipment and conductors. 

NHP