TranSystems Corporation - LGM Construction

501070099 Federal Express Oakland Sort Expansion Issued for Bid 10/11
1. The secondary bus bars shall be tin-plated copper. Main horizontal bus bars shall be mounted with all
three phases arranged in the same vertical plane. Bus sizing shall be based on ANSI standard
temperature rise criteria of 65 degrees C over a 40 degrees C ambient (outside the enclosure).
2. Provide a full capacity neutral bus.
3. A copper ground bus shall be furnished firmly secured to each vertical section structure and shall
extend the entire length of the switchgear. The ground bus short-time withstand rating shall meet that
of the largest circuit breaker within the assembly.
B. Wiring/Terminations
1. Small wiring, necessary fuse blocks and terminal blocks within the switchgear shall be furnished as
required. Control components mounted within the assembly shall be suitably marked for identification
corresponding to the appropriate designations on manufacturer’s wiring diagrams.
2. Provide a front accessible, isolated vertical wireway for routing of factory and field wiring. Factory
provisions shall be made for securing field wiring without the need for adhesive wire anchors.
3. Front access to all circuit breaker secondary connection points shall be provided for ease of
troubleshooting and connection to external field connections without the need of removing the circuit
breaker for access.
4. Lugs shall be provided in the incoming line section for connection of the main grounding conductor.
Additional lugs for connection of other grounding conductors shall be provided as indicated on the
drawings.
C. Main and Tie Circuit Breakers
1. Main and tie circuit breakers shall be drawout type, electrically operated. All closing shall be
electrically supervised. The main and tie circuit breakers shall NOT have any means to manually close
that would bypass the electrical interlocks. Under no conditions shall both main breakers and the tie
breaker be closed concurrently. Manual closing shall be possible only through a control switch that
acts on the electrical operator.
2. The case of the circuit breaker shall be a polyester thermoset material providing high dielectric
strength.
3. All circuit breaker operating mechanisms are to be two-step, fully-stored energy devices for quickmake,
quick-break operation with a maximum of a five-cycle closing time. Open-close-open cycle shall
be possible without recharging. Motor operator shall automatically charge when circuit breaker is
closed.
4. Current-carrying components shall be completely isolated from the accessory mounting area and
double insulated from the operator with accessory cover in place.
5. Padlocking provisions shall be furnished to receive up to three padlocks when circuit breaker is in the
disconnected position, positively preventing unauthorized closing of the circuit breaker contacts.
12 KV – 480/277V SECONDARY DOUBLE-ENDED UNIT SUBSTATIONS 16371-6