Basler BE1-27 User manual

INSTRUCTION MANUAL
FOR
UNDERVOLTAGE, OVERVOLTAGE,
UNDER/OVERVOLTAGE RELAYS
BE1-27, BE1-59, BE1-27/59
P0050-48
Serial No. H12345678910
INST
UNDER OVER
TIME TIME
PICKUP INST INST
POWER
PICKUP
UNDER/OVER VOLTAGE RELAY
BE1-27/59
Style No. A3F E1J A4S3F
UNDER OVER
INST
R
TIME
DELAY TIME DELAY
TIME
INST
INST
TIME
UNDER
OVER
CAUTION: UPPER CONNECTION PLUG MUST BE REMOVED
PRIOR TO REMOVING LOWER CONNECTION PLUG.
Publication: 9170600990
Revision: H 02/08
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INTRODUCTION
This instruction manual provides information about the operation and installation of the BE1-27
Undervoltage Relay, the BE1-59 Overvoltage Relay, and the BE1-27/59 Under/Overvoltage 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.
9170600990 Rev H BE1-27/59 Introduction i
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First Printing: January 1986
Printed in USA
© 2008 Basler Electric, Highland Illinois 62249 USA
All Rights Reserved
February 2008
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.
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]
ii BE1-27/29 Introduction 9170600990 Rev H
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9170600990 Rev H BE1-27/59 Introduction iii
REVISION HISTORY
The following information provides a historical summary of the changes made to the BE1-27, BE1-59, and
BE1-27/59 instruction manual (9170600990). Revisions are listed in reverse chronological order.
Manual
Revision and Date Change
H, 02/08 •Consolidated sensing input range options in style chart of Figure 1-2
to cover all relay models.
G, 09/07 •Updated Output Contacts ratings in Section 1.
•Moved content of Section 6, Maintenance to Section 4.
•Updated front panel illustrations to show laser graphics.
•Moved content of Section 7, Manual Change Information to manual
introduction.
•Added manual part number and revision to all footers.
•Updated cover drawings.
•Updated power supply burden data in Section 1.
•Updated target Indicator description in Section 3.
F, 06/07 •Updated specifications listed in Section 1.
E, 07/04 •Added missing square root symbol to equations of System Voltages
paragraph in Section 3, Functional Description.
D, 06/03 •Revised Resistive and Inductive Output Contact Ratings on page 1-4.
•Updated the Definite Time Accuracy setting on page 1-5.
•Deleted Range 2 row from Figures 3-2 through 3-4.
•Added a new step (Step 3) under Timing for instantaneous to page 5-
4.
•Changed the table that Note 2 referred to in Figure 5-2.
•Page 5-5, Table 5-3, Timing Test Results, Definite Timing Type specs
were changed.
C, 11/99 •Revised the manual to the current standard format.
•Changed characteristic curves figures in Section 3 to improve the
accuracy.
•Added ground terminals to new Figures 1-1 and 4-16.
•Added interconnection diagrams, Figures 4-13, 4-14, and 4-15.
•Added Section 7, Manual Change Information.
—, 01/86 •Initial release
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iv BE1-27/29 Introduction 9170600990 Rev H
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9170600990 Rev H BE1-27/59 Introduction v
CONTENTS
SECTION 1 •GENERAL INFORMATION................................................................................................ 1-1
PURPOSE........................................................................................................................................... 1-1
APPLICATION .................................................................................................................................... 1-1
Motor Protection ........................................................................................................................... 1-1
Automatic Transfer Switching....................................................................................................... 1-1
Cogeneration ................................................................................................................................ 1-1
Transformer Protection................................................................................................................. 1-1
Ground Fault Detection ................................................................................................................ 1-1
MODEL AND STYLE NUMBER.......................................................................................................... 1-2
Style Number Example................................................................................................................. 1-4
SPECIFICATIONS .............................................................................................................................. 1-4
Voltage Sensing Inputs................................................................................................................. 1-4
Undervoltage and Overvoltage Pickup Range ............................................................................. 1-4
Timing Characteristics .................................................................................................................. 1-4
Output Contacts............................................................................................................................ 1-5
Power Supply................................................................................................................................ 1-5
Target Indicators........................................................................................................................... 1-5
Type Tests .................................................................................................................................... 1-5
Physical ........................................................................................................................................ 1-6
Agency Recognition/Certification.................................................................................................. 1-6
SECTION 2 •CONTROLS AND INDICATORS ....................................................................................... 2-1
INTRODUCTION................................................................................................................................. 2-1
SECTION 3 •FUNCTIONAL DESCRIPTION........................................................................................... 3-1
INTRODUCTION................................................................................................................................. 3-1
SYSTEM VOLTAGES ......................................................................................................................... 3-1
STEP-DOWN TRANSFORMER ......................................................................................................... 3-2
LOW-PASS FILTER AND FULL WAVE RECTIFIER ......................................................................... 3-2
PICKUP SETTINGS............................................................................................................................ 3-2
PICKUP COMPARATORS.................................................................................................................. 3-2
TIMER CIRCUIT ................................................................................................................................. 3-2
OUTPUTS ........................................................................................................................................... 3-6
PUSH-TO-ENERGIZE OUTPUT PUSHBUTTONS ............................................................................ 3-6
POWER SUPPLY STATUS OUTPUT ................................................................................................ 3-6
POWER SUPPLY ............................................................................................................................... 3-6
TARGET INDICATORS ...................................................................................................................... 3-6
Internally Operated Targets.......................................................................................................... 3-6
Current Operated Targets ............................................................................................................ 3-6
SECTION 4 •INSTALLATION.................................................................................................................. 4-1
INTRODUCTION................................................................................................................................. 4-1
RELAY OPERATING GUIDELINES AND PRECAUTIONS ............................................................... 4-1
MOUNTING......................................................................................................................................... 4-1
CONNECTIONS................................................................................................................................ 4-14
MAINTENANCE ................................................................................................................................ 4-19
STORAGE......................................................................................................................................... 4-19
SECTION 5 •TESTING ............................................................................................................................ 5-1
INTRODUCTION................................................................................................................................. 5-1
REQUIRED TEST EQUIPMENT ........................................................................................................5
-1
OPERATIONAL TEST ........................................................................................................................ 5-1
Power Supply Status Output ........................................................................................................ 5-1
Pickup ........................................................................................................................................... 5-1
Timing ........................................................................................................................................... 5-4
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9170600990 Rev H BE1-27/59 General Information 1-1
SECTION 1 •GENERAL INFORMATION
PURPOSE
The BE1-27 Undervoltage, BE1-59 Overvoltage and the BE1-27/59 Under/Overvoltage Relays are solid-
state devices which provide reliable protection for generators, motors, and transformers against adverse
system voltage conditions.
APPLICATION
Electric power systems are designed for constant voltage operation. Loads utilizing commercial electric
power are designed to operate at a constant input voltage level with some tolerance. Radical voltage
variations on a power system are indicative of a system malfunction. Protective relays which monitor
system voltage and provide an output signal when the voltage goes outside predetermined limits, find a
variety of applications. Some of these applications include motor and transformer protection, interface
protection for cogeneration systems, and supervision of automatic transfer switching schemes.
Motor Protection
When selecting the type of protection for motor applications, the motor type, voltage rating, horsepower,
thermal capability during start-up, and exposure to automatic transfer restarting following a voltage
interruption need to be considered. During motor start-up, a low terminal voltage condition will inhibit the
motor from reaching rated speed. The BE1-27 Undervoltage Relay will detect this low voltage condition
and trip. Critical applications requiring continuous motor operation and applications where overloads
during start-up may be maintained for a given time period, usually have a definite time or inverse time
delay characteristic incorporated to avoid unnecessary tripping during low voltage dips. If the
undervoltage condition persists for the established time delay, the relay output contacts are connected to
the station alarm annunciator panel, allowing the station operator to take corrective action. The BE1-59
Overvoltage Relay is applied to insure the voltage does not exceed the limits established by the machine
manufacturer for proper operation. Overvoltage conditions stress the insulation level of the equipment and
may cause a dielectric breakdown resulting in a flash over to ground.
Automatic Transfer Switching
Distribution substations are sometimes designed with duplicate supply circuits and transformers to
eliminate service interruptions due to faults located on the primary feeder. In order to restore service
within a given acceptable time period, automatic transfer switching can be applied to initiate the throw
over from primary power to the alternate power source. The BE1-27 Undervoltage Relay can initiate
switching after a given time delay to void transfer switching during temporary low voltage conditions. To
return the substation to normal service upon the restoration of primary voltage, the BE1-59 Overvoltage
Relay supervises the transition to its normal operating condition.
Cogeneration
Utilities employ the use of a voltage check scheme to supervise reclosing at the substation when
cogenerators are connected to a radial distribution feeder and the cogenerator is capable of supplying the
entire load when the utility circuit breaker is open. During a faulted condition, the utility requires the
cogenerator to be disconnected from the system before reclosing the utility breaker. If the cogenerator is
connected to the system, the utility will reclose to an energized line.
This could result in reconnecting two systems out of synchronism with each other. A BE1-27
Undervoltage Relay monitoring the line voltage will inhibit reclosing of the utility circuit breaker if the line is
energized by the cogenerator.
At the interface between the utility and the cogenerator, overvoltage and undervoltage relays are installed
as minimum protection to provide an operating voltage window for the cogenerator. During faulted
conditions, when the cogenerator may become overloaded, the BE1-27 Undervoltage Relay will detect
the decline in voltage and remove the cogenerator from the system. The BE1-59 Overvoltage Relay will
protect the system from overvoltage conditions that occur when power factor correction capacitors are
located on the feeder.
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Transformer Protection
Voltage relays can be applied to protect large transformers from damage as a result of overexcitation.
The concern for transformer overvoltage may be minimized in many power system applications where
proper voltage control of the generating unit is provided. However, where a tap changing regulating
transformer is located between the generating source and the load, some form of voltage protection may
be required to supplement the tap changing control and to prevent equipment damage due to over, as
well as undervoltage resulting from a failure of the tap changing control. The BE1-27/59
Under/Overvoltage Relay is well suited for these applications.
Ground Fault Detection
In a three-phase, three-wire system, a single conductor may break or the insulation may deteriorate
resulting in a high resistance ground fault which may not be detected by the overcurrent relays. This
condition, however, may be sensed by an overvoltage relay connected to a grounded wye, broken delta
set of potential transformers (PT's) as illustrated in Figure 1-1 with this connection, and a sensitive relay
setting, an unbalanced voltage condition such as described above, can be quickly detected and isolated.
BE1-59
7
6
D2816-13
05-29-98
Figure 1-1. Ground Fault Detection
MODEL AND STYLE NUMBER
BE1-27, BE1-59, and BE1-27/59 electrical characteristics and operational features are defined by a
combination of letters and numbers that make up the style number. Model number BE1-27/59 designates
the relay as a Basler Electric Under/Overvoltage Protective 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 BE1-27/59 relay is illustrated in Figure 1-2.
1-2 BE1-27/59 General Information 9170600990 Rev H
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Figure 1-2. Style Number Identification Chart
9170600990 Rev H BE1-27/59 General Information 1-3
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1-4 BE1-27/59 General Information 9170600990 Rev H
Style Number Example
If a BE1-27/59 relay has a style number of A3F–E1J–A0S1F, the relay has the following features:
A ------- Single-phase voltage sensing input
3-------- Sensing input compatible with a pickup adjustment range of 55 to 160 Vac
F-------- Two normally open output relays (one per function)
E1------ Definite timing for each function
J -------- Relay control power is 125 Vdc or 120 Vac, nominal
A ------- Two internally operated target indicators (one per function)
0-------- No instantaneous functions
S ------- Push-to-energize outputs
1-------- Two normally-open auxiliary output relays (one per function)
F-------- Semi-flush mounting case
SPECIFICATIONS
Electrical and physical specifications are listed in the following paragraphs.
Voltage Sensing Inputs
Nominally rated at 50/60 Hz, (120/240 V or 100/200 V) with a maximum continuous voltage rating of 360
V (120 V nominal) or 480 V (240 V nominal) at a burden less than 1 VA per phase. Frequency range is
from 40 to 70 Hz.
Undervoltage and Overvoltage Pickup Range
Pickup Range: Continuously adjustable over the range of 1 to 40, 55 to 160, or 110
to 320 Vac as defined by the Style Chart. See Section 3, Functional
Description, System Voltages, for explanation of pickup ranges.
Pickup Accuracy: ±2% or ±0.5 volts of the pickup setting, whichever is greater.
Dropout: ±2% of pickup.
Timing Characteristics
Instantaneous: Less than 50 milliseconds for a voltage level that exceeds the pickup
setting by 5% or 1 volt, whichever is greater
Definite: Adjustable from 0.1 to 9.9 seconds, in steps of 0.1 seconds.
Accuracy is ±2% or ±50 milliseconds, whichever is greater. (A setting
of 0.0 provides instantaneous timing.)
Inverse: Inverse curve types are defined by the Style Chart and are
represented by the curves shown in Section 3, Functional
Description. Inverse time is adjustable from 01 to 99 in increments of
01. Incrementing the time dial varies the inverse curve along the Y
axis. A setting of 00 designates instantaneous timing.
Accuracy is within ±5% or 50 milliseconds (whichever is greater) of
the indicated time for any combination of the time dial setting and
pickup setting and is repeatable within ±2% or 50 ms (whichever is
greater) for any combination of time dial and tap setting. Curves
were generated with Prefault voltage at 10% greater than pickup for
the 27 curves and 10% less than pickup for the 59 curves. For
Prefault voltages that are greater in difference from the pickup
setting, the timing accuracy is ±10% or 100 ms (whichever is
greater).
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9170600990 Rev H BE1-27/59 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)
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
K (midrange) 48 Vdc 24 to 150 Vdc 3.8 W
125 Vdc 24 to 150 Vdc 4.0 W
J (midrange)
120 Vac 90 to 132 Vac 17.1 VA
L (low range) 24 Vdc 12 to 32 Vdc ∗3.9 W
48 Vdc 24 to 150 Vdc 3.8 W
Y (midrange)
125 Vdc 24 to 150 Vdc 4.0 W
250 Vdc 68 to 280 Vdc 4.1 W
Z (high range)
240 Vac 90 to 270 Vac 28.4 VA
∗Type L 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
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: 2,000 Vac
applied for 1 min
Impulse Test: Qualified to IEC 255-5
Radio Frequency Interference: Qualified to IEEE C37.90.2-1995, Standard for Withstand Capability
of Relay Systems to Radiated Electromagnetic Interference from
Transceivers.
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1-6 BE1-27/59 General Information 9170600990 Rev H
Surge Withstand Capability: Qualified to IEEE C37.90.1-1989, Standard Surge Withstand
Capability (SWC) Tests for Protective Relays and Relay Systems.
Physical
Temperature
Operating Range: –40 to 70°C (–40 to 158°F)
Storage Range: –65 to 100°C (–85 to 212°F)
Weight: 14 lbs (6.35 kg)
Case Size: S1 (See Section 4 for panel cutting/drilling 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.
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SECTION 2 •CONTROLS AND INDICATORS
INTRODUCTION
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. Location of Controls and Indicators
9170600990 Rev H BE1-27/59 Controls and Indicators 2-1
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2-2 BE1-27/59 Controls and Indicators 9170600990 Rev H
Table 2-1. Control and Indicator Descriptions
Locator Description
A Undervoltage Pickup Control. Establishes setpoint for the timed undervoltage function.
Continuously adjustable over the range defined by the style number.
B Undervoltage Time Delay Control. Establishes the interval between undervoltage pickup
and the time delayed output. Defined by the style number, this delay is either a user-
adjustable definite time or inversely proportional to the magnitude of the undervoltage
condition. A setting of 0.0 provides an instantaneous response.
Definite - adjustable from 0.0 to 9.9 seconds in 0.1 second increments.
Inverse - adjusts inverse timing characteristic curve relative to the time axis. (See the
characteristic curves in Section 3.)
C Undervoltage Instantaneous Control. Establishes setpoint for the instantaneous
undervoltage function. Continuously adjustable over the range defined by the style
number.
D Overvoltage Pickup Control. Establishes setpoint for the timed overvoltage function.
Continuously adjustable over the range defined by the style number.
E Overvoltage Time Delay Control. Establishes the interval between overvoltage pickup
and the time delayed output. Defined by the style number, this delay is either a user-
adjustable definite time or inversely proportional to the magnitude of the overvoltage
condition. A setting of 0.0 provides an instantaneous response.
Definite - adjustable from 0.0 to 9.9 seconds in 0.1 second increments.
Inverse - adjusts inverse timing characteristic curve relative to the time axis. (See the
characteristic curves in Section 3.)
F Overvoltage Instantaneous Control. Establishes setpoint for the instantaneous
overvoltage function. Continuously adjustable over the range defined by the style
number.
G Power Indicator. This red LED lights when operating power is applied to the relay.
H Target Reset Switch. This switch is operated to reset the target indicators.
I Overvoltage Pickup LED. A red LED that illuminates when overvoltage exceeds the
pickup setting.
J 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 H).
K 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.
L Undervoltage Pickup LED. A red LED that illuminates when undervoltage exceeds the
pickup setting.
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SECTION 3 •FUNCTIONAL DESCRIPTION
INTRODUCTION
BE1-27, BE1-59, and BE1-27/59 relay functions are illustrated in Figure 3-1 and described in the following
paragraphs.
AUX.
TARGET
AUX.
AUX.
AUX.
POWER
SUPPLY
STATUS
OV TIME
DIAL
OV
TIMER
TIMED
OV
COMPARATOR
OV
PICKUP SETTINGS
INST. TIMED
UNDER OVER UNDER OVER
UV TIME
DIAL
UV
TIMER
TIMED
UV
COMPARATOR
UV
INST.
OV
COMPARATOR
INST.
UV
COMPARATOR
POWER
SUPPLY
SENSOR
UV
POWER
SUPPLY
SENSOR
TO INTERNAL
CIRCUITRY
FULL-WAVE
RECTIFIER
LOW-PASS
FILTER
MONITORED
VOLTAGE
OPERATING
POWER
D2354-03
03-11-96
TARGET
TARGET
TARGET
Figure 3-1. Function Block Diagram
SYSTEM VOLTAGES
The BE1-27, BE1-59, and BE1-27/59 relays are available with three sensing input ranges. The 55 to
160V range is intended for use with nominal system voltages of 120V or 69V (120 ÷ √3). The 110 to
320V range is intended for use with nominal system voltages of 240V, 208V (120 x √3) or 277V (480 ÷
√3). The 1 to 40V range is intended for use with a wye/broken delta PT configuration with 120V or 69V
9170600990 Rev H BE1-27/59 Functional Description 3-1
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3-2 BE1-27/59 Functional Description 9170600990 Rev H
(120 ÷√3) line-to-ground secondary voltages. The wye/broken delta PT configuration is a zero sequence
filter capable of producing three times the line-to-ground voltage (3Vo).
STEP-DOWN TRANSFORMER
The monitored system voltage is applied to the primary of an internal potential transformer and stepped
down to internal circuit levels. The transformer provides a high degree of isolation.
LOW-PASS FILTER AND FULL WAVE RECTIFIER
The output of the step-down transformer is low-pass filtered to prevent undesired response to high-
frequency noise. Frequencies above 226 Hz are attenuated. The ac signal is then full-wave rectified to
produce positive-going half-cycles which represent the magnitude of the monitored system voltage.
PICKUP SETTINGS
Controlled by front panel single-turn potentiometers, the pickup settings establish reference voltages
representative of the system voltage which will cause the relay to respond. Pickup settings are individually
adjustable for timed under/overvoltage functions and instantaneous under/overvoltage functions. On BE1-
27/59, Under/Overvoltage Relays, the undervoltage function takes precedence over the overvoltage
function.
PICKUP COMPARATORS
The output of the rectifier circuit is compared to each pickup setting. When the monitored system voltage
is greater than any pickup setting, the effected comparator’s output goes high. When the monitored
system voltage is less than any pickup setting, the effected comparator’s output goes low. The effects of
these outputs are shown below.
Relevant Pickup Setting
Timed Instantaneous
Comparator Undervoltage Overvoltage Undervoltage Overvoltage
High
No effect Lights OV pickup
indicator; initiates
timer
No effect Energizes output
relay
Low
Lights UV pickup
indicator; initiates
timer
No effect Energizes output
relay
No effect
TIMER CIRCUIT
Once initiated, the timer circuit measures the interval from pickup. If the adverse condition continues
through the programmed delay, the timer circuit energizes the appropriate output relay. In relay styles
with inverse timing, the extent to which the monitored system voltage exceeds the pickup setting
influences the actual time delay such that a greater voltage difference from pickup produces a more rapid
response. This response is illustrated in the characteristic curves as shown in Figures 3-2 through 3-7.
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Figure 3-2. Undervoltage, Short Inverse Timing Characteristic Curve
Voltage Difference From Pickup
01
02
03
05
07
10
20
30
40
50
60
80
99
D2857-24.vsd
11-22-99
0.1
1.0
100
1000
Range 2
Range 3
Range 4
0
1
2
345
6
7
8
9101112 0
4
8
121620
24
28
32
36404448 0
8
16
243240
48
56
64
72808896
Time in Seconds
10
Figure 3-3. Undervoltage, Medium Inverse Timing Characteristic Curve
9170600990 Rev H BE1-27/59 Functional Description 3-3
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0.1
1.0
10
1000
Voltage Difference From Pickup
Time in Seconds
01
02
03
05
07
10
20
30
40
50
60
80
99
0
4
8
121620
24
28
32
36404448 0
8
16
243240
48
56
64
72808896
D2857-25
06-09-03
Range 3
Range 4
100
Figure 3-4. Undervoltage, Long Inverse Timing Characteristic Curve
Figure 3-5. Overvoltage, Short Inverse Timing Characteristic Curve
3-4 BE1-27/59 Functional Description 9170600990 Rev H
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