[j.
Fault pressure relay (device 63): Provide a fault pressure relay
sensitive to rate of rise of transformer tank pressure to detect
internal faults in transformer windings. Fault pressure relay shall be
wired to a compatible auxiliary seal-in relay (Device 63X), which shall
trip primary circuit breakers and transformer secondary breakers of the
associated transformer via a lockout relay. Fault pressure relay shall
be transformer mounted and auxiliary relay shall be panel mounted in a
semiflush case. Auxiliary relay shall have trip-indicating targets.]
k.
Thermal relay (device 49): Provide a winding thermal relay, with
associated accessories. Equipment shall indicate the winding
temperature of the transformer, provide automatic cooling fan control,
and shall have one spare single-pole, double-throw contact for remote
indication of overtemperature for connection to a future Supervisory
Control and Data Acquisition (SCADA) System.
l.
Auxiliary control relays:
Provide as required to implement protective
functions and interlocking
as indicated. Auxiliary relays shall have
contacts rated to carry 30
amperes for one minute and 12 amperes
continuously. Coils shall
be a long-life design with a projected
service life of 40 years.
1.
Auxiliary relays used for tripping circuit breakers shall be
multicontact, high-speed relays operating in one-half cycle or
less.
2.
Auxiliary relays for functions other than tripping circuit
breakers shall be normal-speed relays operating in two cycles or
less.
3.
Auxiliary timing relays shall be electro-pneumatic relays with
contacts rated for at least the load they are controlling.
2.2.6.2
Instruments
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NOTE: Select essential instruments and meters. Add
to the specification any special metering not listed
which is required for a specific project. Use of an
Electronic Monitoring System and Electronic Trip
Assemblies in the breakers may eliminate the need
for many individual electro-mechanical meters. This
may also be accomplished on simpler systems by using
the electronic watthour meter and identifying the
desired special programming features. For
SOUTHNAVFACENGCOM projects, provide three thermal
demand ammeters.
**************************************************************************
ANSI C39.1 for electrical indicating switchboard instruments, with one
percent accuracy class, antiparallax pointer, and glare-free face with
scales as indicated and coordinated to the ratios of the current and
potential transformers provided. AC ammeters and voltmeters shall be a
minimum of [50][115] mm [2][4 1/2] inches square, with 4.36 rad 250 degree
scale. Provide single-phase indicating instruments with flush-mounted
transfer switches for reading three phases.
a.
AC ammeters:
Transformer rated, 5-ampere input, 60 Hz.
SECTION 16361N
Page 27
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