Basler BE1-47N User manual

INSTRUCTION MANUAL
FOR
VOLTAGE PHASE SEQUENCE RELAY
BE1-47N
Publication: 9170400990
Revision: H 09/07
www . ElectricalPartManuals . com

www . ElectricalPartManuals . com

9170400990 Rev H BE1-47N Introduction i
INTRODUCTION
This instruction manual provides information about the operation and installation of the BE1-47N Voltage
Phase Sequence Relay. To accomplish this, the following information is provided:
•General Information and Specifications
•Controls and Indicators
•Functional Description
•Installation
•Testing
WARNING!
To avoid personal injury or equipment damage, only qualified personnel should
perform the procedures in this manual.
NOTE
Be sure that the relay is hard-wired to earth ground with no smaller than 12 AWG
copper wire attached to the ground terminal on the rear of the unit case. When
the relay is configured in a system with other devices, it is recommended to use a
separate lead to the ground bus from each unit.
www . ElectricalPartManuals . com

ii BE1-47N Introduction 9170400990 Rev H
First Printing: September 1985
Printed in USA
© 1989, 1998-1999, 2001, 2006-2007 Basler Electric, Highland Illinois 62249 USA
All Rights Reserved
September 2007
It is not the intention of this manual to cover all details and variations in equipment, nor does this manual
provide data for every possible contingency regarding installation or operation. The availability and design
of all features and options are subject to modification without notice. Should further information be
required, contact Basler Electric.
BASLER ELECTRIC
ROUTE 143, BOX 269
HIGHLAND IL 62249 USA
http://www.basler.com, [email protected]
PHONE [phone] FAX [phone]
CONFIDENTIAL INFORMATION
of Basler Electric, Highland Illinois, USA. It is loaned for confidential use, subject
to return on request, and with the mutual understanding that it will not be used in
any manner detrimental to the interest of Basler Electric.
www . ElectricalPartManuals . com

9170400990 Rev H BE1-47N Introduction iii
REVISION HISTORY
The following information provides a historical summary of the changes made to the BE1-47N instruction
manual (9170400990). Revisions are listed in reverse chronological order.
Manual
Revision and Date Change
H, 09/07 •Added manual part number and revision to all footers.
•Updated power supply burden data in Section 1.
•Updated Target Indicator description in Section 3.
G, 07/06 •Moved contents of Section 7, Manual Change Information to the
manual introduction and deleted Section 7.
•Moved contents of Section 6, Maintenance to Section 4 and deleted
Section 6.
•Corrected Target options of style chart (added N) None).
•Corrected/clarified output contact specifications.
•Added Gost R certification statement.
•Updated all front panel illustrations to show laser-cut overlay.
F, 02/01 •Updated the S1 case drawings.
•Updated the style chart.
E, 08/98 •Removed all references to Service Manual 9170400620.
•In Specifications:
oAdded phase rotation sensitivity
oUpdated the dielectric strength information
oUpdated the power supply input voltage range and burden data
oAdded RFI and UL information
•Corrected errors in style chart.
•Revised functional description of power supply.
•Added outline drawings to cover all mounting options.
•Updated manual format.
D, 11/89 •Negative sequence voltage timing accuracy statement clarified.
•Improved wording of test procedures.
•Corrected projection-mount case illustrations.
www . ElectricalPartManuals . com

iv BE1-47N Introduction 9170400990 Rev H
This page intentionally left blank.
www . ElectricalPartManuals . com

9170400990 Rev H BE1-47N Introduction v
CONTENTS
SECTION 1 •GENERAL INFORMATION................................................................................................ 1-1
PURPOSE........................................................................................................................................... 1-1
APPLICATION .................................................................................................................................... 1-1
Phase Rotation Sensitivity............................................................................................................ 1-1
MODEL AND STYLE NUMBER.......................................................................................................... 1-1
Style Number Example................................................................................................................. 1-2
SPECIFICATIONS.............................................................................................................................. 1-3
Voltage Sensing Input .................................................................................................................. 1-3
Power Supply................................................................................................................................ 1-3
Target Indicators........................................................................................................................... 1-3
Negative Sequence Voltage......................................................................................................... 1-3
Undervoltage ................................................................................................................................ 1-4
Overvoltage .................................................................................................................................. 1-4
Output Contacts............................................................................................................................ 1-5
Type Tests.................................................................................................................................... 1-5
Physical ........................................................................................................................................ 1-5
Agency Recognition/Certification ................................................................................................. 1-5
SECTION 2 •CONTROLS AND INDICATORS ....................................................................................... 2-1
INTRODUCTION................................................................................................................................. 2-1
SECTION 3 •FUNCTIONAL DESCRIPTION........................................................................................... 3-1
INTRODUCTION................................................................................................................................. 3-1
VOLTAGE SENSING.......................................................................................................................... 3-1
PHASE SHIFTING.............................................................................................................................. 3-1
PICKUP SCALING.............................................................................................................................. 3-2
LOW-PASS FILTER............................................................................................................................ 3-2
NEGATIVE SEQUENCE VOLTAGE COMPARATOR........................................................................ 3-2
OVERVOLTAGE/UNDERVOLTAGE COMPARATOR....................................................................... 3-2
TIMING................................................................................................................................................ 3-2
OUTPUTS........................................................................................................................................... 3-6
Main Outputs ................................................................................................................................ 3-6
Auxiliary Outputs .......................................................................................................................... 3-6
Power Supply Status Output ........................................................................................................ 3-6
INDICATORS...................................................................................................................................... 3-7
Internally Operated Targets.......................................................................................................... 3-6
Current Operated Targets ............................................................................................................ 3-6
POWER SUPPLY ............................................................................................................................... 3-7
TARGET INDICATORS ...................................................................................................................... 3-7
Internally Operated Targets.......................................................................................................... 3-7
Current Operated Targets ............................................................................................................ 3-7
SECTION 4 •INSTALLATION.................................................................................................................. 4-1
INTRODUCTION................................................................................................................................. 4-1
RELAY OPERATING GUIDELINES AND PRECAUTIONS ............................................................... 4-1
MOUNTING......................................................................................................................................... 4-1
CONNECTIONS................................................................................................................................ 4-12
MAINTENANCE................................................................................................................................ 4-15
STORAGE......................................................................................................................................... 4-15
www . ElectricalPartManuals . com

vi BE1-47N Introduction 9170400990 Rev H
SECTION 5 •TESTING ............................................................................................................................ 5-1
INTRODUCTION................................................................................................................................. 5-1
OPERATIONAL TESTS...................................................................................................................... 5-1
Negative Sequence Voltage Pickup and Dropout........................................................................ 5-1
Overvoltage Pickup and Dropout.................................................................................................. 5-2
Undervoltage Pickup and Dropout................................................................................................ 5-2
VERIFICATION TESTS ...................................................................................................................... 5-3
Definite Time Verification.............................................................................................................. 5-3
Inverse Time Verification.............................................................................................................. 5-3
www . ElectricalPartManuals . com

9170400990 Rev H BE1-47N General Information 1-1
SECTION 1 •GENERAL INFORMATION
PURPOSE
BE1-47N Voltage Phase Sequence Relays respond to negative sequence voltage (V2) which results from
a fault or misconnection on a balanced, three-phase system.
APPLICATION
BE1-47N relays are designed to protect equipment from damage caused by phase failure, reverse phase
sequence, phase unbalance, undervoltage, or overvoltage.
The relay detects reverse phase connection of lines, transformers, motors, generators, and synchronous
condensers and is often applied in automatic transfer schemes to assure connection of proper phase
rotation as well as voltage conditions. When used in a motor application, the relay provides protection by
preventing motor startup during open-phase or reverse-phase conditions and by tripping the motor off line
for phase unbalance, undervoltage, or overvoltage conditions.
Negative sequence voltage is the result of any unequal phase condition on the source. This can be due to
unequal single-phase loads on the system or unequal transformer impedances between phases. A 1 to
2% level can normally be expected in an industrial supply. Any significant increase above this level can
indicate a power service problem and could lead to serious plant problems. The BE1-47N has the ability
to detect negative sequence voltage levels of this magnitude.
Undervoltage and voltage balance relays have traditionally been applied to protect induction motors from
operating with one phase open. These relays may not reliably detect this condition due to the back emf of
the motor on the open phase. However, an induction motor with a starting current of 6 per-unit will
generate a negative sequence voltage of 16% if fully loaded when a fuse opens. The negative sequence
voltage will be somewhat reduced if the motor is not fully loaded. The sensitivity of the BE1-47N and its
insensitivity to frequency allow reliable protection to be applied to motors.
Motor losses and current unbalance increase with the negative-sequence voltage level. The increased
loss due to negative sequence voltage is not a function of motor load but is independent. A machine
operating with 3.5% negative sequence voltage will have its losses increased by 25%. An open fuse on a
power factor correction capacitor bank can result in a significant increase in negative sequence voltage.
The effect of this condition can be costly.
BE1-47N relays can be applied to protect motor buses from an open phase. It can also be applied to
protect critical individual motors, static, and non-rotating loads from the effects of negative sequence
voltage.
A choice of time delay characteristics allows the relay to respond in the desired manner for a wide variety
of transient and fault conditions.
BE1-47N relays may also be used to provide overvoltage and undervoltage protection. A separate time
delay is utilized to prevent shutdown of equipment during minor voltage dips and to permit sequential
operation when the relay is being used in a supervisory capacity.
Phase Rotation Sensitivity
Relays that use phase-to-phase voltage to determine negative sequence are sensitive to phase rotation.
BE1-47N relays are phase rotation sensitive. Unless otherwise noted, all connections shown in this
manual assume ABC rotation.
MODEL AND STYLE NUMBER
BE1-47N electrical characteristics and operational features are defined by a combination of letters and
numbers that make up the style number. Model number BE1-47N designates the relay as a Basler
Electric Voltage Phase Sequence Relay. The model number, together with the style number, describes
the options included in a specific device and appears on the front panel, draw-out cradle, and inside the
case assembly.
The style number identification chart for the BE1-47N relay is illustrated in Figure 1-1.
www . ElectricalPartManuals . com

1-2 BE1-47N General Information 9170400990 Rev H
Figure 1-1. BE1-47N Style Identification Chart
Style Number Example
If a BE1-47N relay has a style number of E3F–E1P–A1R0F, the relay has the following features:
E------- Three-phase, line-to-line voltage sensing
3-------- 120 Vac, 60 Hz nominal sensing voltage input
F-------- Two output relays with normally open (NO) contacts
E1------ Timing characteristic uses definite time delays
P------- Relay control power is 125 Vdc or 120 Vac, nominal
A------- One internally operated target indicator
1-------- Instantaneous undervoltage element
R------- Instantaneous overvoltage element
0-------- No auxiliary output relay
F-------- Semi-flush mounting case
www . ElectricalPartManuals . com

9170400990 Rev H BE1-47N General Information 1-3
SPECIFICATIONS
BE1-47N electrical and physical specifications are listed in the following paragraphs.
Voltage Sensing Input
Voltage
Nominal: 120 or 208 Vac (60 Hz)
100 or 173 Vac (50 Hz)
Maximum Continuous: 160% of nominal
Frequency
Nominal: 50 or 60 Hz (dictated by relay style)
Range
50 Hz Sensing Input: 45 to 55 Hz
60 Hz Sensing Input: 55 to 65 Hz
Burden: ≤2 VA per phase
Power Supply
Power supply types and specifications are listed in Table 1-1.
Table 1-1. Power Supply Ratings
Type Nominal
Input Voltage Input Voltage Range Burden at Nominal
O (midrange) 48 Vdc 24 to 150 Vdc 4.6 W
125 Vdc 24 to 150 Vdc 4.6 WP (midrange) 120 Vac 90 to 132 Vac 17.5 VA
R (low range) 24 Vdc 12 to 32 Vdc ∗4.6 W
48 Vdc 24 to 150 Vdc 4.6 WS (midrange) 125 Vdc 24 to 150 Vdc 4.6 W
250 Vdc 68 to 280 Vdc 4.6 WT (high range) 240 Vac 90 to 270 Vac 24.4 VA
∗Type R power supply initially requires 14 Vdc to begin operating. Once operating, the input
voltage may be reduced to 12 Vdc and operation will continue.
Target Indicators
Electronically latched, manually reset target indicators are optionally available to indicate closure of the
trip output contacts. Either internally operated or current operated targets may be specified. Internally
operated targets should be selected when normally-closed (NC) output contacts are specified.
Current Operated Targets
Minimum Rating: 200 mA flowing through the trip circuit
Continuous Rating: 3 A
1 Second Rating: 30 A
2 Minute Rating: 7 A
Negative Sequence Voltage
Pickup
Setting Range: 2 to 32% of nominal
Increment: 2%
Accuracy: ±1 unit of the percent setting of the negative sequence voltage at
nominal frequency (50 or 60 Hz as defined by the style number)
Dropout: 98% of pickup
www . ElectricalPartManuals . com

1-4 BE1-47N General Information 9170400990 Rev H
Time Delay
Definite
Setting Range: 0.1 to 9.9 s
Increment: 0.1 s
Accuracy: ±5% or ±50 ms of the time setting
Inverse
Setting Range: 01 to 99
Increment: 1
Accuracy: ±5% or ±50 ms of the indicated time of the selected time-dial curve
illustrated in Figure 3-3
Instantaneous
Delay: <50 ms
Undervoltage
Pickup
Setting Range: 2 to 32% below nominal
Increment: 2%
Accuracy: ±1% of the pickup setting
Dropout: 98% of pickup
Time Delay
Definite
Setting Range: 0.1 to 9.9 s
Increment: 0.1 s
Accuracy: ±5% of the time setting
Inverse
Setting Range: 01 to 99
Increment: 1
Accuracy: ±5% or ±50 ms of the indicated time of the selected time-dial curve
illustrated in Figure 3-3
Instantaneous
Delay: <50 ms
Overvoltage
Pickup
Setting Range: 2 to 32% above nominal
Increment: 2%
Accuracy: ±1% of the pickup setting
Dropout: 98% of pickup
Time Delay
Definite
Setting Range: 0.1 to 9.9 s
Increment: 0.1 s
Accuracy: ±5% of the time setting
Inverse
Setting Range: 01 to 99
Increment: 1
Accuracy: ±5% or ±50 ms of the indicated time of the selected time-dial curve
illustrated in Figure 3-3
Instantaneous
Delay: <50 ms
www . ElectricalPartManuals . com

9170400990 Rev H BE1-47N General Information 1-5
Output Contacts
Resistive Ratings
120 Vac: Make, break, and carry 7 Aac continuously
250 Vdc: Make and carry 30 Adc for 0.2 s, carry 7 Adc continuously,
break 0.3 Adc
500 Vdc: Make and carry 15 Adc for 0.2 s, carry 7 Adc continuously,
break 0.3 Adc
Inductive Ratings
120 Vac, 125 Vdc, 250 Vdc: Break 0.3 A (L/R = 0.04)
Type Tests
Shock: Withstands 15 G in each of three mutually perpendicular planes
without structural damage or performance degradation.
Vibration: Withstands 2 G in each of three mutually perpendicular planes,
swept over the range of 10 to 500 Hz for a total of six sweeps, 15
minutes each sweep, without structural damage or degradation of
performance.
Dielectric Strength: Tested in accordance with IEC 255-5 and IEEE C37.90:
All circuits to ground: 2,121 Vdc applied for 1 min
Input to output circuits: 1,500 Vac or 2,121 Vdc applied for 1 min
Radio Frequency Interference: Maintains proper operation when tested for interference in
accordance with IEEE C37.90.2-1987, Standard Withstand
Capability of Relay Systems to Radiated Electromagnetic
Interference from Transceivers.
Surge Withstand Capability: Qualified to IEEE C37.90.1-1989, Standard Surge Withstand
Capability (SWC) Tests for Protective Relays and Relay Systems.
Fast Transient: Qualified to IEEE C37.90.1-1989
Impulse: Qualified to IEC 255-5
Physical
Temperature
Operating Range: –40 to 70°C (–40 to 158°F)
Storage Range: –65 to 100°C (–85 to 212°F)
Weight: 14 lb (6.35 kg)
Case Size: S1 (Refer Section 4 for case dimensions.)
Agency Recognition/Certification
UL Recognition: UL recognized per Standard 508, File E97033
NOTE: Output contacts are not UL recognized for voltages greater
than 250 volts.
Gost-R Certification: Gost-R certified, No. POCC US.ME05.B03391; complies with the
relevant standards of Gosstandart of Russia. Issued by accredited
certification body POCC RU.0001.11ME05.
www . ElectricalPartManuals . com

1-6 BE1-47N General Information 9170400990 Rev H
This page intentionally left blank.
www . ElectricalPartManuals . com

9170400990 Rev H BE1-47N Controls and Indicators 2-1
SECTION 2 •CONTROLS AND INDICATORS
INTRODUCTION
All BE1-47N controls and indicators are located on the front panel. The controls and indicators are shown
in Figure 2-1 and described in Table 2-1. Figure 2-1 illustrates a relay with the maximum number of
controls and indicators. Your relay may not have all of the controls and indicators shown and described
here.
Figure 2-1. BE1-47N Controls and Indicators
Table 2-1. Control and Indicator Descriptions
Locator Description
A Power Indicator. This red LED lights when operating power is applied to the relay.
B Negative Sequence Voltage Controls and Indicator. These elements consist of a pickup
thumbwheel switch, a time delay thumbwheel switch, and a pickup indicator.
The 16-position pickup switch adjusts the negative sequence voltage pickup setpoint.
Switch positions A through S correspond to setpoints ranging from 2 to 32% of the
nominal voltage, in 2% increments. The front panel setting chart (locator D) lists the
setpoint for each switch position.
Relays with definite or inverse timing have a time delay switch that sets the duration of
timing for negative sequence voltage protection. Instantaneous timing is not user-
adjustable, so relays with instantaneous timing do not have a time delay switch.
The red pickup LED lights when the level of negative sequence voltage exceeds the
setting of the negative sequence voltage pickup switch.
www . ElectricalPartManuals . com

2-2 BE1-47N Controls and Indicators 9170400990 Rev H
Locator Description
C Undervoltage Controls and Indicator. These elements consist of a pickup thumbwheel
switch, a time delay thumbwheel switch, and a pickup indicator. Undervoltage elements
are present only if option 1 of the relay style number is 1, 2, or 3.
The 16-position pickup switch adjusts the undervoltage pickup setpoint. Switch positions
A through S correspond to setpoints ranging from 2 to 32% below the nominal (single-
phase) voltage, in 2% increments. The front panel setting chart (locator D) lists the
setpoint for each switch position.
Relays with definite or inverse timing have a time delay switch that sets the duration of
timing for undervoltage protection. Instantaneous timing is not user-adjustable, so relays
with instantaneous timing do not have an undervoltage time delay switch.
The red pickup LED lights when the level of (single-phase) voltage decreases below the
setting of the undervoltage pickup switch.
D Setting Chart. To aid in setting pickup levels, this chart lists the percent difference (from
nominal) setting for each lettered position of the negative sequence voltage, overvoltage,
and undervoltage pickup setting switches.
E Target Reset Switch. This switch is operated to reset the target indicators.
F Output Test Pushbuttons. These pushbuttons allow manual actuation of the output relays.
Output relay actuation is achieved by inserting a nonconductive rod through the front
panel access holes.
G Target Indicators. The electronically latched red target indicators illuminate when the
corresponding output relay energizes. To ensure proper operation of current-operated
targets, the current flowing through the trip circuit must be 200 mA or higher. Target
indicators are reset by operating the target reset switch (locator E).
H Overvoltage Controls and Indicator. These elements consist of a pickup thumbwheel
switch, a time delay thumbwheel switch, and a pickup indicator. Overvoltage elements
are present only if option 2 of the relay style number is R, S, or T.
The 16-position pickup switch adjusts the overvoltage pickup setpoint. Switch positions A
through S correspond to setpoints ranging from 2 to 32% above the nominal (single-
phase) voltage, in 2% increments. The front panel setting chart (locator D) lists the
setpoint for each switch position.
Relays with definite or inverse timing have a time delay switch that sets the duration of
timing for overvoltage protection. Instantaneous timing is not user-adjustable, so relays
with instantaneous timing do not have an overvoltage time delay switch.
The red pickup LED lights when the level of (single-phase) voltage increases above the
setting of the overvoltage pickup switch.
www . ElectricalPartManuals . com

9170400990 Rev H BE1-47N Functional Description 3-1
SECTION 3 •FUNCTIONAL DESCRIPTION
INTRODUCTION
BE1-47N relay functions are illustrated in Figure 3-1 and described in the following paragraphs.
VC
TARGET
47N
POWER SUPPLY
STATUS
D2818-12
07-30-98
VB
VA
PHASE
SHIFT PICKUP SCALING
LOW
PASS
FILTER
REFERENCE
LEVEL
NEGATIVE
SEQUENCE
VOLTAGE
COMPARATOR AND
47N
AUX.
TIMING
TARGET
27/59
AUX.
OR
TIMING
TIMING
POWER
SUPPLY
SENSOR
59
27
UNDERVOLTAGE
COMPARATOR
UNDERVOLTAGE
PICKUP
OVERVOLTAGE
PICKUP
OVERVOLTAGE
COMPARATOR
LOW
PASS
FILTER
POWER
SUPPLY
SENSOR
POWER TO INTERNAL
CIRCUITRY
OPERATING
POWER
V2
SEQUENCE
FILTER
Figure 3-1. Function Block Diagram
VOLTAGE SENSING
One of two nominal voltage levels may be specified for a system frequency of 50 hertz or 60 hertz.
Voltage sensing input options are summarized in Table 3-1.
Table 3-1. Voltage Sensing Input Options
Sensing Input Option Nominal Voltage Frequency
3 120 Vac 60 Hz
4 100 Vac 50 Hz
5 208 Vac 60 Hz
6 173 Vac 50 Hz
Three-phase system voltage is supplied to internal potential transformers (PTs). These PTs are an
integral part of the sequence filter and provide isolation, step-down scaling, and phasor summation to
eliminate the zero-sequence component of the sensed voltages.
PHASE SHIFTING
The respective secondary voltages are phase shifted ±45°each, with respect to signal ground and then
summed to nullify the positive sequence component.
www . ElectricalPartManuals . com

3-2 BE1-47N Functional Description 9170400990 Rev H
PICKUP SCALING
The resolved negative sequence voltage (V2) ac signal is then applied to the pickup scaling network
(switch S1 and its associated resistors). The pickup network establishes per-unit (PU) values of negative
sequence voltage for the comparison and timing functions.
LOW-PASS FILTER
The sensing circuits for negative sequence voltage, overvoltage, and undervoltage are designed to
operate on the fundamental frequencies of 50 or 60 hertz. The low-pass filter passes the fundamental
frequencies and attenuates the higher frequencies.
NEGATIVE SEQUENCE VOLTAGE COMPARATOR
The proportionate negative sequence (V2) signal is compared to a reference level. When the level of the
per-unit negative sequence voltage exceeds the reference level, the pickup indicator lights and timing is
initiated.
OVERVOLTAGE/UNDERVOLTAGE COMPARATOR
Optional single-phase overvoltage and undervoltage circuits operate on the voltage magnitude. The
single-phase ac signal is low-pass filtered and passed to the respective comparator where it is compared
to the pickup settings for each circuit. If either pickup setting has been exceeded (overvoltage or under-
voltage), the appropriate LED lights and timing is initiated.
TIMING
One of three timing characteristics is available for each of the three protection functions: definite, inverse,
or instantaneous. The timing characteristic may be independently selected for each protection function.
Table 3-1 identifies the timing style selections for negative sequence voltage, undervoltage, and over-
voltage protection.
Table 3-1. Timing Characteristic Style Number Selections
Timing Characteristic
Protection Function Instantaneous Inverse Definite
Undervoltage (27) xxx-xxx-x1xxx xxx-xxx-x2xxx xxx-xxx-x3xxx
Negative Sequence Voltage (47N) xxx-A1x-xxxxx xxx-D1x-xxxxx xxx-E1x-xxxxx
Overvoltage (59) xxx-xxx-xxRxx xxx-xxx-xxSxx xxx-xxx-xxTxx
Definite timing is adjustable from 0.1 to 9.9 seconds in increments of 0.1 seconds.
The response time of instantaneous timing is less than 50 milliseconds. When the timing characteristic for
a protection function is definite or inverse and the time delay setting is 00, instantaneous timing is
achieved.
Inverse timing is adjustable from 01 to 99 in increments of 1 (see Figures 3-2 through 3-4 for the inverse
time characteristic curves). When evaluating inverse curves for overvoltage or undervoltage protection,
note that timing is based on the percent difference from the system’s nominal voltage. For example, refer
to Figure 3-4. If the monitored voltage is at a level of 18% below system nominal, the portion of the curves
below 18% (e.g., 13%, 8%, etc.) has no effect on the timing characteristic. In other words, the timing
curve beginning is dependent upon the monitored voltage percent difference from the system’s nominal
voltage. Inverse timing characteristics preceding this defined point are nonexistent.
www . ElectricalPartManuals . com

9170400990 Rev H BE1-47N Functional Description 3-3
MULTIPLES OF PICK-UP SETTING
.05
.01
.1
.5
1
10
5
50
100
1000
500
MULTIPLES OF PICK-UP SETTING
TIME IN SECONDS
1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0
L
A
I
D
E
M
I
T
01
02
03
05
07
10
20
30
40
50
60
80
99
D2818-17
07-31-98
Figure 3-2. Negative Sequence Voltage Inverse Time Characteristic Curves
www . ElectricalPartManuals . com

3-4 BE1-47N Functional Description 9170400990 Rev H
D2818-15
07-31-98
Figure 3-3. Undervoltage Inverse Time Characteristic Curves
www . ElectricalPartManuals . com