TranSystems Corporation - LGM Construction

501070099 Federal Express Oakland Sort Expansion Issued for Bid 10/11
B. Conduct field survey to assess protective characteristics of existing protective devices included
within the scope of this study.
C. Proceed with coordination study only after all new equipment furnished by the contractor as been
submitted.
3.2 FAULT-CURRENT STUDY
A. Source Impedance: The Port of Oakland has advised that 10,000A short circuit current potential is
available at the 12KV level from substation SS8. Substation SS8 is immediately adjacent to the
Security Screening Building at the intersection of Air Cargo Way and Sally Ride Way. Port
substation SS8 feeds Fed Ex’s Main 12KV Distribution Switchgear in the generator building, which
in turn feeds to the new unit substation in the new Sort Building. Refer to the Electrical
Infrastructure electrical drawings for the single-line diagram of the 12KV distribution system.
B. Calculate momentary and interrupting duties on the basis of maximum available fault current.
Summarize results in report.
3.3 COORDINATION STUDY
A. Gather and tabulate the following input data to support coordination study:
1. Product Data for over-current protective devices. Use equipment designation tags that
are consistent with electrical distribution system diagrams, over-current protective device
submittals, input and output data, and recommended device settings.
2. Electrical distribution system one-line diagrams.
3. Data sheets to supplement electrical distribution system diagram, cross-referenced with
tag numbers on diagram:
a. Special load considerations, including starting inrush currents and frequent
starting and stopping.
b. Magnetic inrush current overload capabilities of transformers.
c. Motor full-load current, locked rotor current, service factor, starting time, type of
start, and thermal-damage curve.
d. Ratings, types, and settings of utility company's over-current protective devices.
e. Special over-current protective device settings or types stipulated by utility
company.
f. Time-current-characteristic curves of devices indicated to be coordinated.
g. Manufacturer, frame size, interrupting rating in amperes rms symmetrical,
ampere or current sensor rating, long-time adjustment range, short-time
adjustment range, and instantaneous adjustment range for circuit breakers.
h. Manufacturer and type, ampere-tap adjustment range, time-delay adjustment
range, instantaneous attachment adjustment range, and current transformer ratio
for over-current relays.
i. Panelboards, switchboards, motor-control center ampacity, and interrupting
rating in amperes rms symmetrical.
B. Perform coordination study and prepare a written report using the results of fault-current study and
approved computer software program. Comply with IEEE 399.
ELECTRICAL PROTECTIVE DEVICE COORDINATION 16031 - 3