1.3 RELAY SELECTION
The Model 139 relay
is
available in horizontal
or
vertical
mount
versions and is
equipped
with a
number
of standard features that
are
programmed for a specific
application by means of selector switches. Although these can be changed
1r.
the
field.
they
will
be
factory preset
1f
specified according
to
the
relay
order
code
of
Table 1-2. Each relay
is
shipped with a
yellow
product
specification card vvhich
shows installed options and factory
switch
settings.
Consultthiscardand
Table 1-2
to
determine
how
the
relay has been
equipped.
Relays are available for use with
1or5
amp
current
transformers (CTs) which
must
be
specified with
the
order.
Since
the
relay
only
sees secondary current, any CT
ratio can be used with
the
relay
providing
it has
the
correct
secondary rating
to
match
the
relay (i.e. 1
amp
or
5
amp
type).
Although many features are standard and field selectable.
the
following options
will not
be
provided unless specifically
ordered:
1 I
Ground
Fault
2) RTD Overtemperature
f'.·
3) Thermal Capacity
Meter
4)
4-20mA
Full Load
Output
Stocking of spare relays is simplified
since
many features are field programmable
allowing a relay to be set
up
for
different
applications. Those features that
must
be
specified at
time
of
order
are indicated in Table 1-2.
2
Courtesy of NationalSwitchgear.com
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