Siemens SG8158-00 사용자 설명서

Protective Function Configuration

Siemens Energy & Automation, Inc.

5 Protective Function Configuration

5.1 Overview

This chapter explains how to set the parameters for the

protective functions of the ISGS relay.

Password

All parameter changes require a password. Refer to

Section 3.3 on how to enter your password. Viewing

parameter settings does not require a password.

Note: The ISGS relay is not password protected

when making parameter changes through

Wisdom software.

Configuration Steps

Perform parameter changes using steps 1 through 9 of the

standard operating procedures described in Section 3.5.

Parameter Sets

Many protective functions can be set to two different param-

eter setsset A and set B. These functions are indicated by

the letter A or B preceding the address block number. Alter-

nate sets are useful for seasonal settings or for special oper-

ating periods. Either set can be selected (in address block

7100) to be the active set that controls the relay operation.

The parameters for both sets are entered in the relevant

address blocks. Waveform capture buffer settings apply to

both parameter sets. Unless you do not desire an alternate

set, configure both sets when configuring the relay.

Note: The settings for parameter sets A and B are

entered in the address block. However, the

parameter set which the ISGS relay is

actively using is selected at address block

7100. Refer to Section 6.11 for discussion

of parameter sets.

Actions on Pickup or Trip

Protective functions can be set to have actions occur on

pickup or on trip. Binary outputs can be set to be actuated

on pickup of a protective function. A protective function is set

to trip a breaker by assigning the trip contact that is con-

nected to the breaker (default is Trip 1). Binary outputs can

also be assigned to trip a breaker. It is possible, however to

have a protective function enabled and not assigned to any

output. Events and their sequences are entered in the trip log

as usual, but the breaker will not be affected. This setting is

useful for monitoring and alarming without tripping, and for

waveform capture. For more information on the control of

inputs and outputs, refer to Chapter 6.

Pickup

When testing induction disk relays, an established practice is

to set the pickup value to 1.0 A of secondary CT output. The

time overcurrent curves will show a pickup, but the relay will

not trip in a predefined repeatable manner until it reaches 1.3

to 1.5 A. With numerical relays like the ISGS, however, a sus-

tained pickup indication means definite operation. To

account for measurement inaccuracies, and to guarantee

that the relay will never trip at 100% of pickup or below, the

pickup point is set at 106% of the pickup setting to avoid any

unintended nuisance trips.

Neutral or Ground

The availability of protective functions for neutral or ground

depends on how the external CTs are connected. If a ground

or zero-sequence CT is used and connected to the fourth

internal CT, the ground or neutral protective function is a

ground function. If the fourth CT is connected in the common

return of the other three internal CTs (residual), the function is

indicated as being neutral. There does not need to be an

explicit selection of neutral or ground.

Custom Curve

The custom curve is one user-defined curve that can be

used by one or more protective functions that have the cus-

tom curve option in the curve list.

Wisdom Software

While the ISGS relay protective functions can be completely

configured manually using the LCD and the keypad, Wisdom

software allows faster and easier configuration when it is

used on a PC connected to either data port. For data port

connections refer to Section 2.5.

5.2 Instantaneous Phase Overcurrent (50)

The Instantaneous Phase Overcurrent function consists of a

phase instantaneous overcurrent function and an adjustable

delay. This function begins timing when any individual phase

current exceeds the pickup at 100% of set pickup point and

drops out at 95% of the pickup point.

The function can be enabled or disabled (1501).

The range of the pickup value (1502) depends on the sec-

ondary phase CT rating (1 A or 5 A), and the value is in sec-

ondary amperes.

The time delay (1504) represents the time between pickup

and trip and can be adjusted from 0 to 60 seconds in steps

of 0.1 second. If the function remains in pickup for longer

than the time delay, the function causes a trip. The delay can

also be set to infinity so that the function never times out.

Each of the two waveform capture buffers (1510 and 1511)

can be independently programmed to freeze snapshots on

pickup or trip.

The function is able to actuate any binary output contact on

pickup, and any trip or binary output contact on trip.

A1500 Instantaneous Phase Overcurrent (50)

Address Parameter

Option

1501 Function

Enabled or Disabled

1502 Pickup

5 A CTs: 1-120 A

1 A CTs: 0.2-24 A

(0.1 A steps)

1504 Time Delay

0-60 s (0.01 s steps)

1510 Freeze Wfm1

on Pickup, on Trip, or None

1511 Freeze Wfm2

on Pickup, on Trip, or None

1512 Blocked by

None, 50HS & 50HSN, 50 HSN,

or 50HS

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