Schweitzer Engineering SEL-387-0 Instruction Manual Download Page 36

Page: 36 / 556

2.10

SEL-387-0, -5, -6 Relay

Instruction Manual

Date Code 20170601

Installation

Rear-Panel Connections

Current Transformer Inputs

Connect current inputs to the four sets of current input terminals. Note that the
CT shorting connectors providing current connections to Connectorized relays
install in only one orientation. Note also that the current input terminals on
both terminal block and Connectorized relays have a mark at one terminal per
phase to indicate polarity. Each current input is independent of the other two
inputs. Current inputs are designated

IAW1

IBW1

ICW1

;

IAW2

IBW2

ICW2

;

IAW3

IBW3

ICW3

; and

IAW4

IBW4

, and

ICW4

Optoisolated Inputs

Connect control input wiring to the six standard inputs

IN101

–

IN106

and to any

of the interface board optoisolated inputs

IN201

–

IN208

you need for your

application.

All control inputs are dry optoisolated inputs and are not polarity dependent.
Specify a nominal rated control voltage of 48, 110, 125, 220, or 250 Vdc for
level sensitive and 24 Vdc for nonlevel sensitive when ordering. To assert an
input, apply nominal rated control voltage to the terminals assigned to that
input. A terminal pair is brought out for each input. Refer to

General on

page 1.8

for optoisolated input ratings. There are no internal connections

between inputs. ON and OFF values are normally within one volt of each
other, in the indicated range.

Output Contacts

Connect output wiring to the SEL-387 main board eight standard independent
output contacts,

OUT101

through

OUT107

and

ALARM

. Standard independent dry

output contacts are not polarity dependent; the left side of

Figure 2.7

shows

these contacts as they would appear on a terminal block version.

Figure 2.7

Standard Independent Output Contact Representation

Connect output wiring to any of the additional output contacts

OUT201

–

OUT212

you need for your application. On the additional interface board, you have the
option of either standard or high current interrupting contacts.

High current

interrupting contacts are polarity dependent.

A plus polarity mark next to

the terminal requiring positive dc voltage identifies these contacts on a relay
rear panel. The right side of

Figure 2.7

shows this polarity mark for high

current interrupting contacts. Ensure correct polarity; reversed polarity causes
a short circuit to appear across the contact terminals.

Communications Port

Refer to

Table 2.1

for a list of cables that you can purchase from SEL for

various communication applications. Refer to

Section 7: Serial Port

Communications and Commands

for detailed cable diagrams for selected

cables.

WARNING

Before working on a CT circuit, first
apply a short to the secondary
winding of the CT.

NOTE:

When installing CT shorting

connectors, ensure that you secure
each connector to the relay chassis
with the screws at each connector
end. When removing a CT shorting
connector, pull it straight away from
the relay rear panel. Removing a
shorting connector causes internal
mechanisms within the

connector to

individually short out each power
system current transformer.

NOTE:

Listing of devices not

manufactured by SEL is for the
convenience of our customers. SEL
does not specifically endorse or
recommend such products nor does
SEL guarantee proper operation of
those products, or the correctness of

connections, over which SEL has no
control.