In October 2011, Tapeswitch Corp. proposed a power isolation interlock system with an exchange key unit from their trapped key interlock product line for the maintenance facility of a leading transit authority in Boston to ensure safe maintenance and repair operations and to secure worker safety. The system Tapeswitch implemented was a unique and complete solution, which allowed control of multiple operations, while ensuring reliable safety. It has been in place since March 2011 and has been well received by the maintenance personnel.
Tapeswitch Corp. was invited to engineer a replacement for its current combination of interlocks and panels from multiple manufacturers to implement a complete solution. Tapeswitch Corp. provided a fully integrated Castell system, consisting of its power isolation panel interlock and exchange key interlock to effectively streamline and secure multiple maintenance operations. Since power is being generated by the Acela system, personnel must follow a predetermined process before beginning maintenance operations. For instance, when a train pulls into the maintenance facility, the release of an electrical power isolation interlock confirms power disconnection, trapping an exchanged key until the enabling solenoid is de-energized. The power is safely controlled until the overhead conductor rail has been retracted and is no longer a hazard to the maintenance workers requiring access to dangerous areas. The system then releases exchange keys that activate maintenance power panels and a maintenance lift. Additional exchange keys released that energizes the panels that run onboard systems for test and repair. When work is completed, the process is reversed, releasing the key controlling the power and allowing power to be returned, so the train can leave the facility safely.
The main power isolation interlocks KSD32 is a key driven 32 amp switch disconnector suitable for the isolation or switching of 32 amp (maximum) current. The type of disconnector used is suitable for "on load" isolation and is suitable for extended periods of isolation. The standard KSD comes with six poles plus two auxiliary early break contacts. The KSD is manufactured from either brass or stainless steel, making it suitable for use in standard or harsh corrosive environments. The unit is supplied suitable for mounting into an existing panel or for surface mounting within its own IP65 rated lockable steel enclosure. The X key exchange box is a product designed to enable the release of keys by the insertion of one or more primary key(s). The need for this type of product usually arises when there are more keys required than the initial isolation system supplies. The unit will generally be the link between the isolation locks and the access products. The product is supplied in an enclosure suitable for surface mounting and is available in many configurations and numbers of locks.