Basler BE1-40Q User manual

INSTRUCTION MANUAL
FOR
LOSS OF EXCITATION RELAY
BE1-40Q
Publication: 9171500990
Revision: M 01/11
P0050-23
40Q

9171500990 Rev M BE1-40Q Introduction i
INTRODUCTION
This instruction manual provides information about the operation and installation of the BE1-40Q Loss of
Excitation 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.

ii BE1-40Q Introduction 9171500990 Rev M
First Printing: November 1986
Printed in USA
©1986-2011 Basler Electric, Highland Illinois 62249 USA
All Rights Reserved
January 2011
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.

9171500990 Rev M BE1-40Q Introduction iii
REVISION HISTORY
The following information provides a historical summary of the changes made to the BE1-40Q instruction
manual (9171500990). Revisions are listed in reverse chronological order.
Manual
Revision and Date Change
M, 01/11 Updated equations in Note 1 under Figure 5-2.
Improved timing specs under Operational Test, Timing Verification in
Section 5.
L, 09/07 Added manual part number and revision to footers.
Updated Output Contact ratings in Section 1.
Updated Power Supply Burden data in Section 1.
Updated front panel illustrations to show laser graphics.
Updated Target Indicator description in Section 3.
Added GOST-R to Section 1, General Information.
Moved content of Section 7, Manual Change Information to Manual
Introduction.
Moved content of Section 6, Maintenance to Section 4, Installation.
K, 02/01 Updated S1 case drawings in Section 4 to the most recent drawings.
J, 10/98 Corrected Voltage Sensing in Specifications from “Each have a
burden that is less than 0.1 ohm over the” to “Each have a burden
that is less than 1 VA over the”.
Deleted 500 Vdc from Resistive Output Circuits.
Deleted all references to Service Manual.
Updated Style Number Identification Chart by changing Power Supply
Type T from “230 Vac” to “240 Vac”.
Added new power supply information to Specifications and Section 3
starting with “Basler Electric enhanced the power supply design…”
Changed the format of the manual.
H, 03/95 Changed Section 1, General Information, Specifications, Output
Circuits and Isolation.
Added phase rotation sensitivity information to Section 3, Functional
Description.
Changed Section 4, Installation, Dielectric Test, to reflect specification
changes.
Corrected Figure 4-1 and changed Figure 5-2, note 2.
Corrected typographical error in Table 5-4, Reactive Power (Vars),
+120.
Corrected typographical error in Section 6, Maintenance, General.
G, 01/94 Deleted references to mho characteristic.
Corrected Figure 4-3 (Sensing Input Test Setup), current sensing
input terminals 8 and 9 were reversed on earlier versions;
renumbered equations; updated format; and added new internal
connection diagrams Figures 4-3 through 4-5, added new mounting
diagrams Figures 4-6 through 4-14.
Added new Section 5, Setting and Testing, moved appropriate data
from Section 4 into Section 5, and changed Section 5 and 6 to
Section 6 and 7.

iv BE1-40Q Introduction 9171500990 Rev M
Manual
Revision and Date Change
F, 01/91 Pages 1-3, 1-5 (Style Chart), 1-7 2-1 (Item H), 4-4 (step 3), 4-7 (Step
3): Time delay range is 0.1 to 9.90 seconds, adjustable in increments
of 0.1 seconds. This was previously unclear or (in some cases)
erroneous.
Page 1-8: RFI specification added.
Pages 1-6, 5-1: minor editing.
E, 09/90 Legend of Figure 3-2 corrected.
Page 3-1 (under “Phase Shift”): 68was 52.
D, 08/89 Equations 4.1 through 4.4 put into standard form by removing
negative sign from the angle theta.
C, 06/89 Figure 3-2 corrected.
Equations on page 4-8 restated for clarification.
Arithmetical errors corrected in the example given on page 4-8.
Table 4-2 corrected.
Figure 4-3 was reformatted.
Figure 4-7 revised to clarify installation.
B, 11/88 Minor corrections and editing.
A, 11/88 Figure 3-3 added.
Editing changes made to clarify specifications.
Two articles added to Section 4, entitled, “Setting the Pickup” (page
4-5) and, “Relay Characteristic Verification” page 4-7.
—, 01/86 Initial release

9171500990 Rev M BE1-40Q Introduction v
CONTENTS
SECTION 1 •GENERAL INFORMATION................................................................................................ 1-1
PURPOSE........................................................................................................................................... 1-1
APPLICATION .................................................................................................................................... 1-1
Capability Curves ......................................................................................................................... 1-1
BE1-40Q Operating Characteristics ............................................................................................. 1-1
TimeDelay.................................................................................................................................... 1-1
MODEL AND STYLE NUMBER.......................................................................................................... 1-3
Style Number Example................................................................................................................. 1-3
SPECIFICATIONS .............................................................................................................................. 1-4
Current Sensing............................................................................................................................ 1-4
Current Sensing Burden ............................................................................................................... 1-4
Voltage Sensing ........................................................................................................................... 1-4
Pickup Range ............................................................................................................................... 1-4
Pickup Accuracy ........................................................................................................................... 1-4
Dropout ......................................................................................................................................... 1-4
Time Delay Range........................................................................................................................ 1-4
Timing Accuracy ........................................................................................................................... 1-4
Output Contacts............................................................................................................................ 1-5
Power Supply................................................................................................................................ 1-5
Target Indicators........................................................................................................................... 1-6
Type Tests .................................................................................................................................... 1-6
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
VOLTAGE SENSING .......................................................................................................................... 3-1
PHASE SHIFT..................................................................................................................................... 3-1
CURRENT SENSING ......................................................................................................................... 3-2
HI/LOW RANGE SWITCH .................................................................................................................. 3-2
TAP SWITCH ...................................................................................................................................... 3-3
TRANSDUCER ................................................................................................................................... 3-3
COMPARATOR .................................................................................................................................. 3-3
TIMING................................................................................................................................................ 3-3
OUTPUTS ........................................................................................................................................... 3-3
PUSH-TO-ENERGIZE OUTPUT PUSHBUTTON .............................................................................. 3-3
POWER SUPPLY STATUS OUTPUT ................................................................................................ 3-3
POWER SUPPLY ............................................................................................................................... 3-3
TARGET INDICATORS ...................................................................................................................... 3-4
Internally Operated Targets.......................................................................................................... 3-4
Current Operated Targets ............................................................................................................ 3-4
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

vi BE1-40Q Introduction 9171500990 Rev M
SECTION 5 •TESTING ............................................................................................................................ 5-1
SETTING............................................................................................................................................. 5-1
Per Unit Conversion Example ...................................................................................................... 5-1
OPERATIONAL TEST ........................................................................................................................ 5-2
Introduction ................................................................................................................................... 5-2
Pickup Verification ........................................................................................................................ 5-2
Timing Verification ........................................................................................................................ 5-4
Relay Characteristics Verification................................................................................................. 5-4

9171500990 Rev M BE1-40Q General Information 1-1
SECTION 1 •GENERAL INFORMATION
PURPOSE
Loss of excitation protection is applied on nearly all synchronous generators. Reduced or complete loss of
excitation can cause loss of synchronism, instability and, possibly, damage to the generator from
overheating. Many modern excitation systems include minimum-excitation limiters to prevent
underexcitation; however, loss of excitation protective relays are still applied as backup to these
automatic controls. BE1-40Q Loss of Excitation Relays provide this protection by monitoring the field
excitation (measuring the magnitude and direction of var flow) and tripping the generator before serious
damage to the generator can occur.
Synchronous generators in parallel are normally operated in the overexcited (lagging) region, which
allows generation of reactive power (vars). Although the field excitation may be safely adjusted to cause
the generator to absorb vars (leading), this is usually avoided because stability is unreliable under this
condition.
When field excitation is not sufficient to maintain the terminal voltage of an interconnected generator, the
system will attempt to supply reactive power to excite the generator. If the system cannot supply the
required vars, the weakened field may allow the rotor to slip poles during disturbances such as load
changes or faults, causing loss of synchronism.
When the system can supply the necessary vars, the generator will act as an induction generator,
drawing excitation from the system. The machine voltage will remain above the setting of undervoltage
relays, but the current induced by the rotor slip will flow in the damper (amortisseur) windings. The
excessive heating caused by the current flow reduces machine life exponentially.
Under either condition, BE1-40Q Relays will detect the increased vars at the generator terminals as a loss
of excitation and trips the generator to prevent loss of synchronism or excessive heating within the
generator.
APPLICATION
Capability Curves
Generator manufacturers supply capability curves that specify the operating limits of a particular machine
(similar to those shown in Figure 1-1). The curves are derived from the heating characteristics that occur
on the stator end iron, the stator winding, and the rotor winding. Plotted on the complex power plane, real
power P (kW) is on the horizontal axis and reactive power Q (var) is on the vertical axis.
An additional limit is often included on these curves, as shown in Figure 1-2. Here, the steady state
stability limit further defines the safe operating limit of the generator. If the stability limit is exceeded, an
out-of-step condition can occur due to loss of synchronism.
BE1-40Q Operating Characteristics
BE1-40Q relay characteristics closely follow the generator capability curves. The response characteristic
is represented by a line eight degrees from horizontal, placed above the most restrictive limit of normal
operation. As shown in Figure 1-3, the attendant intercept of the line on the Q axis (at –0.4 per unit vars in
this example) is used to establish the pickup of the relay. A front panel rotary switch is used to set the
TAP setting. Refer to Section 5, Setting and Testing, for specific information on determining the pickup
setting.
Time Delay
A time delay is included in BE1-40Q Relays to prevent misoperation for transient conditions such as
power swings due to synchronizing or external fault clearing. A definite time delay of 0.1 to 9.9 seconds
can be set on the front panel thumbwheels in increments of 0.1 second. Setting both thumbwheels to 0
causes an instantaneous trip signal to be sent when the TAP setting is exceeded. Refer to Section 5 for
specific setting information.

1-2 BE1-40Q General Information 9171500990 Rev M
Figure 1-1. Typical Generator Capability Curve
Figure 1-2. Normal Operation with Steady State Stability Limit
Figure 1-3. An example of BE1-40Q Relay Operating Characteristics

9171500990 Rev M BE1-40Q General Information 1-3
MODEL AND STYLE NUMBER
BE1-40Q electrical characteristics and operational features are defined by a combination of letters and
numbers that make up the style number. Model number BE1-40Q designates the relay as a Basler
Electric Loss of Excitation 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 BE1-40Q relay is illustrated in Figure 1-4.
Figure 1-4. BE1-40Q Style Identification Chart
Style Number Example
If a BE1-40Q relay has a style number of F3E–E1O–B1S2F, the relay has the following features:
F-------- 60 Hz single-phase current sensing
3-------- 120 Vac, 25-1000 var
E-------- One output relay with normally open contacts
E1 ------ Definite timing
O------- Operating power derived from 48 Vdc
B-------- One current operated target
1-------- Push-to-energize output
S-------- Power supply status output
2-------- One auxiliary output relay with normally closed contacts
F-------- Semi-flush mounting case

1-4 BE1-40Q General Information 9171500990 Rev M
SPECIFICATIONS
BE1-40Q electrical and physical specifications are listed in the following paragraphs.
Current Sensing
Unit is designed to operate from the secondary of a standard current transformer rated at 5 A, 50 and 60
Hz (based on configuration). Internal current sensing transformers are rated at 10 A continuous, 15 A for
1 minute, and 200 A for 1 second.
Current Sensing Burden
Maximum sensing burden is less than 0.1 ohm at pickup over the frequency range of 45 to 65 Hz.
Voltage Sensing
Three line-to-line voltage sensing inputs are available: 120, 208, and 240 Vac (nominal). Each have a
burden that is less than 1 VA over the frequency range of 45 to 65 Hz.
Pickup Range
Refer to Table 1-1.
Table 1-1. Pickup Ranges
Sensing Input
Range Tap A B C D E F G H J K
2
120 Vac
HI 20 40 60 80 100 120 140 160 180 200
LOW 5.0 10 15 20 25 30 35 40 45 50
3
120 Vac
HI 100 200 300 400 500 600 700 800 900 1000
LOW 25 50 75 100 125 150 175 200 225 250
5
208 Vac
HI 40 80 120 160 200 240 280 320 360 400
LOW 10 20 30 40 50 60 70 80 90 100
6
208 Vac
HI 200 400 600 800 1000 1200 1400 1600 1800 2000
LOW 50 100 150 200 250 300 350 400 450 500
8
240 Vac
HI 40 80 120 160 200 240 280 320 360 400
LOW 10 20 30 40 50 60 70 80 90 100
9
240 Vac
HI 200 400 600 800 1000 1200 1400 1600 1800 2000
LOW 50 100 150 200 250 300 350 400 450 500
Pickup Accuracy
±2% of the front panel setting or ±0.1 var, whichever is greater for a power factor angle of –90°.
Dropout
Not less than 95% of actual pickup.
Time Delay Range
Definite time delay is adjustable by two front panel thumbwheels over a range of 01 to 99 (0.1 to 9.9
seconds) in increments of 0.1 seconds. A setting of 00 enables instantaneous operation.
Timing Accuracy
Shown in Figure 1-5. Note that each curve is slightly offset by a factor that represents integration time.
Repeatability is within ±5% or 25 milliseconds, whichever is greater.

9171500990 Rev M BE1-40Q General Information 1-5
Figure 1-5. Typical Relay Response Time for Time Dial Settings
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 1-2.
Table 1-2. Power Supply Ratings
Type Nominal
Input Voltage Input Voltage Range Burden at Nominal
O (midrange) 48 Vdc 24 to 150 Vdc 1.9 W
P (midrange)
125 Vdc 24 to 150 Vdc 2.2 W
120 Vac 90 to 132 Vac 18.4 VA
R (low range) 24 Vdc 12 to 32 Vdc ∗1.9 W
S (midrange)
48 Vdc 24 to 150 Vdc 1.9 W
125 Vdc 24 to 150 Vdc 2.2 W
T (high range)
250 Vdc 68 to 280 Vdc 2.3 W
240 Vac 90 to 270 Vac 32.1 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.

1-6 BE1-40Q General Information 9171500990 Rev M
Target Indicator
An electronically latched, manually reset target indicator is optionally available to indicate closure of the
trip output contact. Either an internally operated or a current operated target may be specified. An
internally operated target should be selected when a normally closed (NC) output contact is specified.
Current Operated Target
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. All circuits to
ground: 2,121 Vdc. Input to Output circuits: 1,500 Vac/2,121 Vdc.
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.
Physical
Temperature
Operating Range: –40 to 70°C (–40 to 158°F)
Storage Range: –65 to 100°C (–85 to 212°F)
Weight: 13.5 lb (6.12 kg)
Case Size: S1 (Refer to 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 per the relevant standards of Gosstandart of
Russia.

9171500990 Rev M BE1-40Q Controls and Indicators 2-1
SECTION 2 •CONTROLS AND INDICATORS
INTRODUCTION
All BE1-40Q 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. BE1-40Q Controls and Indicators
Table 2-1. Control and Indicator Descriptions
Locator Description
A Tap Switch. A ten-position rotary switch sets the pickup point when used in conjunction
with the Range switch (see Locator I). Pickup levels (in vars) are labeled on the Tap
Range Chart (see Locator E).
B Pickup Indicator. LED illuminates to indicate that the pickup level has been exceeded.
C Power Indicator. This red LED lights when operating power is applied to the relay.
D Target Reset Switch. This switch is operated to reset the target indicator.
E Tap Range Chart. Provides an index of reactive power levels (in vars) that correspond to
the Tap switch positions.

2-2 BE1-40Q Controls and Indicators 9171500990 Rev M
Locator Description
F Output Test Pushbutton. This pushbutton allows manual actuation of the output relay.
Output relay actuation is achieved by inserting a nonconductive rod through the front
panel access hole.
G Target Indicator. The electronically latched red target indicator illuminates when the
corresponding output relay energizes. To ensure proper operation of the current-operated
target, the current flowing through the trip circuit must be 200 mA or higher. The target
indicator is reset by operating the target reset switch (locator D).
H Time Delay Selectors. Two thumbwheel switches select the trip time delay. The left
thumbwheel represents seconds; the right thumbwheel represents tenths of a second.
I Range Switch. Two-position switch selects the reactive power range (HI or LOW) desired.

9171500990 Rev M BE1-40Q Functional Description 3-1
SECTION 3 •FUNCTIONAL DESCRIPTION
INTRODUCTION
BE1-40Q Loss of Excitation relays are static devices that respond to the relation of voltage to current
magnitudes of the monitored circuit. As such, they are sensitive to phase rotation. All connections shown
in this manual assume ABC rotation. BE1-40Q relay functions are illustrated in Figure 3-1 and described
in the following paragraphs.
Figure 3-1. Function Block Diagram
VOLTAGE SENSING
The monitored voltage input is derived from a system voltage transformer connected phase-to-phase. An
internal voltage transformer (PT) provides isolation and reduces the nominal value of the voltage sensing
input (i.e., 120, 208, or 240 Vac) to internal circuitry requirements.
PHASE SHIFT
Since the voltage input, VAB, leads the sensed input current, IB, by an angle of 150°for a unity power factor
condition, the voltage phasor is internally shifted 68°in a lagging direction (delayed) to achieve the relay
response characteristics. The resultant ITRIP leads the polarizing voltage VPOL by 8°(when the system
power factor angle (Ө) is equal to–90°as shown in Figure 3-2.

3-2 BE1-40Q Functional Description 9171500990 Rev M
Figure 3-2. Phase Shift Example
The response of the relay is:
Front Panel Pickup Setting =
( ) ( )






°
−°








8cos
8
sin
3
θ
BAB
IV
Or
( )








−°
°








=
θ 8sin
8cos3
SettingPickupPanelFront
AB
B
V
I
Where:
VAB = phase A to phase B voltage magnitude
IB= phase B current magnitude
Ө= system power factor angle = (voltage angle) –(current angle)
CURRENT SENSING
The monitored current is derived from the secondary of a system current transformer rated nominal five
amperes. An internal current transformer (CT) provides isolation and scaling for proper relay operation.
The front panel HI/LOW RANGE switch uses the tapped secondary of the internal CT for range selection
to increase pickup stability.
Note that when the connection plugs (paddles) are removed, the CT inputs are shorted.
HI/LOW RANGE SWITCH
The front panel HI/LOW RANGE switch selects which secondary winding of the internal CT is connected
to the TAP switch and thus the measurement circuitry. The position of this switch may be changed while

9171500990 Rev M BE1-40Q Functional Description 3-3
sensing current is present. The effect of this switch, in conjunction with the TAP switch, is shown in the
Specifications, Table 1-1, and on the front panel tap range chart.
TAP SWITCH
The front panel TAP switch selects the pickup setting (in single-phase vars), depending on the position of
the HI/LOW RANGE switch, as shown in Table 1-1. The TAP switch selects the resistive burden value
that is placed across the output of the internal sensing input CT. The resistive burden establishes the
scaling of the internal signal that represents the input current value.
TRANSDUCER
The transducer consists of a multiplier and integrator. The multiplier and associated control circuits
produce an output that is representative of the product of the scaled current input and the scaled, phase-
shifted voltage input signal. The output waveform of the multiplier is an instantaneous value; therefore,
the output is integrated to develop a signal that represents the average var value. The integrator
response time is a function of the pickup multiple, as shown in Section 1, Specifications.
COMPARATOR
The signal representing the single-phase var value is compared with the pickup reference. When the
reference value is exceeded, the PICKUP LED indicator is illuminated and timing is initiated.
TIMING
A definite time delay is initiated when the monitored var level exceeds the pickup reference. A calibrated
frequency generating circuit, in conjunction with counter circuits and the front panel TIME DELAY
thumbwheel switches, establishes the definite time delay interval.
Time delay is adjustable from 0.1 to 9.9 seconds in 0.1-second intervals. A setting of 00 enables
instantaneous (no intentional time delay) operation. Timing is instantaneously reset if the var level
reduces to less than the pickup setting.
For a complete description of timing accuracy, refer to Specifications in Section 1.
OUTPUTS
Defined by the style number, the output relay may have either a normally open (NO) or normally closed
(NC) configuration. The normally open output contact option is required when a current operated target is
desired.
In addition, an auxiliary output contact may be provided which is specified by style number as NO, NC, or
SPDT. If an auxiliary contact is provided, then the power supply status output is not available.
PUSH-TO-ENERGIZE OUTPUT PUSHBUTTON
A small pushbutton switch may be provided as an option to allow testing the primary output contact and (if
present) the auxiliary output contact. To prevent accidental operation, the pushbutton is recessed behind
the front panel and is depressed by inserting a thin, non-conducting rod through an access hole in the
front panel.
POWER SUPPLY STATUS OUTPUT
The power supply status relay has a set of normally closed contacts and energizes when operating power
is applied to the BE1-40Q. If relay operating power is lost or either side of the power supply output
(+12 Vdc or –12 Vdc) fails, the power supply status relay de-energizes and opens the power supply
status output contacts.
POWER SUPPLY
Operating power for the relay circuitry is supplied by a wide range, electrically isolated, low-burden power
supply. Power supply operating power is not polarity sensitive. The front panel power LED and power
supply status output indicate when the power supply is operating. Power supply specifications are listed in
Table 1-1.

3-4 BE1-40Q Functional Description 9171500990 Rev M
TARGET INDICATOR
A target indicator is an optional component selected when a relay is ordered. The electronically latched
and reset target consists of a red LED indicator located on the relay front panel. A latched target is reset
by operating the target reset switch on the front panel. If relay operating power is lost, an illuminated
(latched) target is extinguished. When relay operating power is restored, the previously latched target is
restored to its latched state.
A relay can be equipped with either an internally operated target or current operated target.
The relay trip output is directly applied to drive the target indicator. The indicator is illuminated regardless
of the current level in the trip circuit.
Internally Operated Target
A current operated target is triggered by closure of the output contact
Current Operated Target
and
NOTE
the presence of at least 200
milliamperes of current flowing in the trip circuit.
Prior to September 2007, BE1-40Q the target indicator consisted of a
magnetically latched, disc indicator. This mechanically latched target indicator
has been replaced by the electronically latched LED target in use today.