Littelfuse PGR-8800 User manual

Pub. PGR-8800-M. December 14, 2012 • www.littelfuse.com • © 2012 Littelfuse • • 1/82
Arc-Flash Relay
PGR-8800
PGR-8800
ARC-FLASH RELAY
DECEMBER 14, 2012
REVISION 2
PGR-8800 SERIES
ARC-FLASH RELAY

PGR-8800 Arc-Flash Relay Rev. 2
Pub. PGR-8800-M. December 14, 2012 • www.littelfuse.com • © 2012 Littelfuse • • 2/82

PGR-8800 Arc-Flash Relay Rev. 2
Pub. PGR-8800-M. December 14, 2012 • www.littelfuse.com • © 2012 Littelfuse • • 3/82
TABLE OF CONTENTS
1 INTRODUCTION............................................................................................................. 7
1.1 Current-Supervised Arc-Flash Protection.................................................................. 7
1.2 Definite-Time Overcurrent Protection........................................................................ 7
1.3 Fail-Safe Operation.................................................................................................... 7
1.4 Fast Fault Location .................................................................................................... 7
1.5 USB Interface............................................................................................................. 8
1.6 Scalable System ........................................................................................................ 8
1.7 Upstream Circuit Breaker Tripping ............................................................................ 8
2 INSTALLATION............................................................................................................... 9
3 POWER SUPPLY.......................................................................................................... 12
3.1 AC Supply................................................................................................................ 12
3.2 DC Supply................................................................................................................ 12
3.3 Low-Voltage DC Supply........................................................................................... 13
3.4 External 24-V Battery Backup.................................................................................. 13
4. OPTICAL SENSORS .................................................................................................... 14
4.1 PGA-LS10 Photoelectric Point Sensor with Sensor Check..................................... 15
4.1.1 PGA-LS10 Connection.......................................................................................... 16
4.1.2 PGA-LS10 Installation........................................................................................... 17
4.2 PGA-LS20 and PGA-LS25 Fiber-Optic Sensor with Sensor Check........................ 18
4.2.1 Fiber Connection................................................................................................... 18
4.2.2 Receiver Wiring Connections................................................................................ 18
4.2.3 Transmitter Wiring Connections............................................................................ 18
4.2.4 PGA-LS20 and PGA-LS25 Connection ................................................................ 19
4.2.5 Fiber-Optic Sensor Adjustment............................................................................. 20
4.2.5.1 Sensor Adjustment for a Fiber Length other than 60 cm.................................. 20
4.2.5.2 Sensor Adjustment in Small Compartments ..................................................... 20
5 SENSOR PLACEMENT................................................................................................ 21
5.1 General Guidelines.................................................................................................. 21
5.2 Switchgear Protection.............................................................................................. 21
5.3 Transformer Protection............................................................................................ 21
6 CURRENT SENSORS .................................................................................................. 22
6.1 Current Inhibit Mode ................................................................................................ 22
6.2 Overcurrent Protection............................................................................................. 22
6.3 Current Sensor Characteristics................................................................................ 23
7 DIGITAL INPUTS .......................................................................................................... 24
7.1 Inhibit........................................................................................................................ 24
7.2 Trip........................................................................................................................... 24
7.3 Reset........................................................................................................................ 24
7.4 Circuit Check............................................................................................................ 24
8 OUTPUTS ..................................................................................................................... 25
8.1 Online....................................................................................................................... 25

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8.2 Service..................................................................................................................... 25
8.3 Tripped..................................................................................................................... 25
8.4 Trip Coil.................................................................................................................... 26
9 LED INDICATION.......................................................................................................... 27
10 PGR-8800 BUTTONS.................................................................................................. 30
10.1 Mode ........................................................................................................................ 30
10.2 Trip........................................................................................................................... 30
10.3 Reset........................................................................................................................ 30
10.4 Mode + Reset........................................................................................................... 30
10.5 Mode + Trip.............................................................................................................. 30
11 LINK ............................................................................................................................. 31
11.1 Configuration............................................................................................................ 31
11.2 Button Function........................................................................................................ 31
11.3 Modbus Communication.......................................................................................... 32
12 USB Interface............................................................................................................... 33
12.1 Connecting to a PC.................................................................................................. 33
12.2 Configuration Software ............................................................................................ 34
12.2.1 Configuration Software Tabs....................................................................... 34
12.2.2 Configuration Software Buttons .................................................................. 35
12.2.3 Default Configuration .................................................................................. 35
12.2.4 General Settings.......................................................................................... 36
12.2.5 Optical-Sensor Settings .............................................................................. 36
12.2.6 Current-Sensor Settings.............................................................................. 38
12.2.7 Digital-Input Settings................................................................................... 40
12.2.8 Output Settings............................................................................................ 41
12.2.8.1 Trip Coil Output....................................................................................... 41
12.2.8.2 Coordinated Tripping .............................................................................. 42
12.2.9 Communications Settings ........................................................................... 43
12.2.10 Advanced Settings ...................................................................................... 46
12.2.11 About Tab.................................................................................................... 47
12.3 Data Log Drive......................................................................................................... 47
13 COMMISSIONING....................................................................................................... 48
13.1 Configuration of Installed Sensors........................................................................... 48
13.2 Testing the Sensors................................................................................................. 48
13.3 Testing the Trip Coil................................................................................................. 49
13.4 Full Operation Test (Online)..................................................................................... 49
13.5 Light Sensitivity Adjustment..................................................................................... 49
14 SPECIFICATIONS....................................................................................................... 50
15 ORDERING INFORMATION ....................................................................................... 53
16 WARRANTY................................................................................................................. 54
Appendix A PGR-8800 MODBUS RTU Protocol................................................................ 55
A.1 Protocol ........................................................................................................................ 55
A.1.1 Configuration Setup........................................................................................ 55

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A.2 Message Synchronization............................................................................................ 55
A.3 Error Checking.............................................................................................................. 55
A.4 Function Codes Supported........................................................................................... 56
A.4.1 Read Input/Holding Registers (Code 04/03).................................................. 56
A.4.2 Write to Register............................................................................................. 56
A.4.2.1 Write Single Register (Code 6) ............................................................... 56
A.4.2.2 Write Multiple Registers (Code 16)......................................................... 57
A.4.3 Exception Responses..................................................................................... 57
A.5 PGR-8800 Database.................................................................................................... 57
A.6 Specifications ............................................................................................................... 57
Appendix B Modbus Communications Database Table..................................................... 58
Appendix C Coordinated Tripping of Upstream Breakers.................................................. 64
C.1 System Overview ......................................................................................................... 64
C.1.1 Circuit Breaker Feedback Detection.............................................................. 64
C.1.2 Current Sensor Detection............................................................................... 64
C.1.3 Total Clearing Time........................................................................................ 64
C.1.3.1 Arc Detection Delay ................................................................................ 64
C.1.3.2 Circuit Breaker Operating Time .............................................................. 64
C.1.3.3 Output Delay ........................................................................................... 65
C.1.3.4 Total Clearing Time Examples................................................................ 65
C.1.4 Relay Output .................................................................................................. 65
C.1.5 Link Output..................................................................................................... 65
C.1.6 D1100 Diode Logic Unit ................................................................................. 65
C.2 Application and Configuration...................................................................................... 66
C.2.1 Single PGR-8800 Configuration..................................................................... 66
C.2.2 Dual PGR-8800 Configuration using Link Interface....................................... 70
C.2.3 Single PGR-8800 Configuration with Current Sensor Input........................... 71
C.2.4 Dual PGR-8800 Configuration using Link Interface and
Current Sensor Input ...................................................................................... 74
C.2.5 Configuration of Multiple Inputs and Outputs................................................. 76
C.2.6 Tripping Common Upstream Circuit Breaker from Several Zones
using D1100.................................................................................................... 77
Appendix D System Parameters and Setup Record.......................................................... 78

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LIST OF FIGURES
1 PGR-8800 Outline and Mounting Details....................................................................... 9
2 PGR-8800 Typical Wiring Diagram.............................................................................. 10
3 PGR-8800 24-Vdc Source Wiring Diagram................................................................. 11
4 Local Sensor Detection Zone for a 3 kA Fault............................................................. 14
5 PGA-LS10 Detection Range for a 3 kA Fault .............................................................. 15
6 PGA-LS10 Connection Diagram.................................................................................. 16
7 PGA-LS10 Mounting Details........................................................................................ 17
8 PGA-LS20 and PGA-LS25 Connection Diagram ........................................................ 19
9 LED Flash Patterns...................................................................................................... 27
C.1 Single PGR-8800 Application........................................................................................ 67
C.2 Dual PGR-8800 Configuration using Link Interface..................................................... 70
C.3 Single PGR-8800 Configuration with Current Sensor Input ........................................ 72
C.4 Dual PGR-8800 Configuration using Link Interface and
Current Sensor Input ................................................................................................... 74
C.5 Tripping Common Upstream Circuit Breaker from Several Zones
using D1100.................................................................................................................. 77

PGR-8800 Arc-Flash Relay Rev. 2
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1 INTRODUCTION
The PGR-8800 Arc-Flash Relay is a high-speed, arc-detection device for electrical power-
distribution systems. The PGR-8800 has one local sensor and supports both point and fiber-optic
sensor technologies for optical arc detection. There are inputs for six optical sensors and three
current sensors.
On the occurrence of an arc fault, the PGR-8800 detects the fault and pulses the trip contact in
less than 1 ms. The tripping pulse is typically used to trip the circuit breaker(s) supplying the circuit.
The total arcing time is effectively reduced to the mechanical opening time of the circuit breaker;
typically between 30 and 75 ms. The trip contact is a solid-state switch (IGBT), which provides fast
reaction and sufficient drive capability for circuit-breaker trip circuits.
Using optical sensors rather than relying strictly on current measurement allows a much faster
detection time than overcurrent relays or a circuit breaker alone can typically provide. This will
lower the incident energy of an arc flash and increase worker safety, reduce fault damage, and
improve uptime. Since the incident energy is decreased, the hazard risk category (HRC) and
associated level of personal protective equipment (PPE) may also be lowered, subject to an arc-
flash study modeling the system parameters.
The MODBUS RTU protocol is implemented in the PGR-8800. This will provide status information
for sensors, analog inputs, digital inputs, digital outputs, and numerous event and error flags. It
also provides the ability to remotely reset the PGR-8800. See Section 11.3 and Appendices A and
B.
The PGR-8800 can be used on any electrical system with any voltage (ac or dc) and can be
powered from either an ac or dc supply, or both. If it is powered from line supply, it can charge a
backup battery to power the PGR-8800 when the line supply is lost.
1.1 Current-Supervised Arc-Flash Protection
The PGR-8800 has three phase-current inputs which can be used to prevent optical trips when the
measured current is below a user-specified level. This makes it possible to avoid nuisance tripping
from external light sources such as lightning or welding arcs.
1.2 Definite-Time Overcurrent Protection
Using the phase-current inputs, the PGR-8800 can be configured to trip on overcurrent, with a
minimum reaction time of 1 ms. There are two user-adjustable levels of overcurrent protection with
independent trip times to coordinate with other protective devices. This provides protection from
long-lasting overload conditions and fast reaction to overcurrent even when no arc is detected.
1.3 Fail-Safe Operation
The PGR-8800 continuously monitors its internal circuitry as well as the connected optical sensors.
Any system faults, including a sensor-cable fault, are indicated by a flashing LED and can be
logged. A redundant trip circuit ensures that the PGR-8800 will trip on an arc flash even if a
primary trip-circuit component fails. The solid-state design of the redundant trip circuit also
provides a significantly faster response to an arc on power-up (for example, after maintenance
during a shutdown) than is possible with microprocessor-only relays.
1.4 Fast Fault Location
The optical sensors used with the PGR-8800 include LED indication of health and, if it has
detected an arc flash, of fault location. The PGR-8800 also has one LED per optical sensor to
indicate which sensor(s) have caused a trip.

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1.5 USB Interface
A USB interface on the front of the PGR-8800 provides easy PC access to configuration settings
and access to an event log which provides detailed diagnostic information about measurements
before and after a trip. No PC driver or software installation is required.
1.6 Scalable System
Up to four PGR-8800 modules can be connected into a single system, allowing a total of 24 optical
sensors per system.
1.7 Upstream Circuit Breaker Tripping
The PGR-8800 can be configured to trip an upstream circuit breaker as a backup to local circuit-
breaker failure. Circuit-breaker failure can be detected with a discrete input (such as a local circuit
breaker feedback signal), current measurement, or the Link function. See Appendix C for more
information.

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2 INSTALLATION
The PGR-8800 can be surface mounted using four 5-mm (10-32) screws, or it can be DIN-rail
mounted using the optional mounting brackets (PGA-0031).
Ensure there is enough clearance around the module to allow the plug-in terminals to be removed
and inserted.
Do not install modules which have been damaged in transport.
See the PGR-8800 Arc-Flash Relay Application Guide for additional installation information.
54.3
(2.14)
38.8
(1.53)
SIDE
BOTTOM
TOP
FRONT
200.0
(7.88)
20.0
(0.79)
20.0
(0.79)
160.0
(6.30)
130.2
(5.13)
122.2
(4.81)
4.0
(0.16)
4.0
(0.16)
4 OPEN SLOTS
5.6 X 6.8 (0.22 x 0.27)
6.0
(0.24)
5.0
(0.20)
130.0 (5.13)
NOTES:
1. DIMENSIONS IN MILLIMETRES (INCHES).
NOTE 2
2. MINIMUM CLEARANCE REQUIRED FOR CONNECTOR
INSERTION AND REMOVAL.
10.0
(0.39)
NOTE 2
10.0
(0.39)
MOUNTING DETAIL
200.0
(7.88)
20.0
(0.79)
20.0
(0.79)
160.0
(6.30)
PGR-8800 SERIES
ARC-FLASH RELAY
FIGURE 1. PGR-8800 Outline and Mounting Details.

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PGR-8800 SERIES
ARC-FLASH RELAY
LINK OR MODBUS CONNECTION (OPTIONAL)
+
-
TRIP
COIL
ABC
OPTIONAL
5-A-SECONDARY
PHASE CT’S
PGA-LS20 / PGA-LS25
FIBER OPTIC SENSOR
OPTIONAL
24 VDC BATTERY
SEE SECTION 3
UPTO 4
PGR-8800 MODULES
CAN BE CONNECTED. SEE
SECTION 11.
RG
ALARM ONLINE
TO UPSTREAM
CIRCUIT BREAKERTRIP COIL
24-250 VAC
R
TRIP
NOTE 3
RED
WHITE
YELLOW
BLACK
NOTE 4
PGA-LS10
POINT SENSOR
NOTES:
1. RELAY OUTPUTS SHOWN DE-ENERGIZED.
2. CURRENT SENSOR INPUTS MUST BE CONFIGURED. SEE SECTION 12.
3.TERMINALS 33 AND 36 ARE INTERNALLY CONNECTED FOR PGR-8800-00 ONLY.
4. ATOTAL OF SIX POINT OR FIBER-OPTIC SENSORS CAN BE CONNECTED.
5. USB ‘B’ CONNECTOR. FOR CONFIGURATION, SEE SECTION 12.
RESET
NOTE 5
RED
WHITE
RED
WHITE
YELLOW
SHIELD / BLACK
SHIELD / BLACK
FIGURE 2. PGR-8800 Typical Wiring Diagram.

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PGR-8800 SERIES
ARC-FLASH RELAY
+
-ABC
RGR
RED
WHITE
YELLOW
BLACK
+24 VDC
LINK OR MODBUS CONNECTION (OPTIONAL)
TRIP
COIL
OPTIONAL
5-A-SECONDARY
PHASE CT’S
PGA-LS20 / PGA-LS25
FIBER OPTIC SENSOR
UPTO 4
PGR-8800 MODULES
CAN BE CONNECTED. SEE
SECTION 11.
ALARM ONLINE
TO UPSTREAM
CIRCUIT BREAKERTRIP COIL
TRIP
NOTE 3
NOTE 4
PGA-LS10
POINT SENSOR
NOTE 5
RED
WHITE
RED
WHITE
YELLOW
SHIELD / BLACK
SHIELD / BLACK
NOTES:
1. RELAY OUTPUTS SHOWN DE-ENERGIZED.
2. CURRENT SENSOR INPUTS MUST BE CONFIGURED. SEE SECTION 12.
3.TERMINALS 33 AND 36 ARE INTERNALLY CONNECTED FOR PGR-8800-00 ONLY.
4. ATOTAL OF SIX POINT OR FIBER-OPTIC SENSORS CAN BE CONNECTED.
5. USB ‘B’ CONNECTOR. FOR CONFIGURATION, SEE SECTION 12.
24-250 VAC
RESET
0 V
FIGURE 3. PGR-8800 24-Vdc Source Wiring Diagram.

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3 POWER SUPPLY
The PGR-8800 Arc-Flash Relay can be supplied by ac or dc voltage.
3.1 AC Supply
Connect an ac supply to terminals 31 and 32. The supply voltage must be 100 to 240 Vac.
100-240 VAC
NL
GND
31
L2/
N
32
L1
33
LINE
3.2 DC Supply
Connect a dc supply to terminals 31 and 32, ensuring correct polarity. The supply voltage must be
110 to 250 Vdc.
-+GND
110-250 VDC
31
L2/
N
32
L1
33
LINE

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3.3 Low-Voltage DC Supply
Connect a dc supply to terminals 34 and 36, ensuring correct polarity. The supply voltage must be
14 to 48 Vdc.
NOTE: For the PGR-8800-00 order option, terminal 36 (0 V) is internally connected to
terminal 33 ( ) and chassis. If necessary, use an isolated DC Supply.
14-48 VDC
36
0
V
35
B
A
T
34
+
V
POWER
+-
3.4 External 24-V Battery Backup
Connect a 24-Vdc battery to terminals 35 and 36, ensuring correct polarity. The PGR-8800 will
charge the battery when there is rated voltage on power-supply terminals 31 and 32 (ac or dc).
The PGR-8800 supplies a constant-current, constant-voltage (CCCV) of 27 V with no load and
maximum available current of 200 mA. A sealed lead-acid battery with a capacity between 2 and
15 Ah, such as a pair of Panasonic VRLA LC-R122R2P, should be used and exchanged regularly
according to the manufacturer’s recommendations.
If the PGR-8800 is supplied by the backup battery and the battery voltage drops below 20 V, the
PGR-8800 will shut down to protect the battery.
Do not combine external battery backup and the low-voltage DC supply. The DC supply will not
charge the battery.
NOTE: For the PGR-8800-00 order option, terminal 36 (0 V) is internally connected to
terminal 33 ( ) and chassis. If necessary, use an isolated DC Supply.
NOTE: Arc monitoring is disabled when the PGR-8800 is powered down.
+-
36
0
V
34
+
V
35
B
A
T
POWER
24 VDC
BATTERY

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4 OPTICAL SENSORS
The PGR-8800 has one local sensor and six inputs for external optical sensors. The local sensor
is primarily used for commissioning and can also be enabled for arc-flash protection. Its light-
detection zone is illustrated in the diagram below.
PGR-8800 SERIES
ARC-FLASH RELAY
ARC-FLA
2 m
70°
1 m
150°
FIGURE 4. Local Sensor Detection Zone for a 3 kA Fault.
Two external sensor types are supported:
PGA-LS10 Photoelectric Point Sensors with sensor check
PGA-LS20 and PGA-LS25 Fiber-Optic Sensors with sensor check
The sensors can be used together, in any combination.
Both sensor types have LED indication of sensor health and fault location. A sensor-check circuit
tests the sensor to verify that the sensor assembly is functioning correctly. A healthy sensor will
indicate two fast flashes of its internal red LED every few seconds. A sensor that has detected an
arc will slowly flash red.
The sensors connect to the PGR-8800 with shielded three-wire 0.5 mm2(20 AWG) electrical cable.
Each sensor includes 10 m of cable which can be shortened or extended up to 50 m. These
cables should be considered to be at ground potential when determining electrical clearances.
Any connected optical sensor with circuit check will be automatically detected and cause the
PGR-8800 to report an error if it is subsequently disconnected.
PGA-LS10 PGA-LS20 / PGA-LS25

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4.1 PGA-LS10 Photoelectric Point Sensor with Sensor Check
This sensor has a detection area of a 2-m half-sphere for arcs of 3 kA or more.
A built-in LED enables the PGR-8800 to verify the function of the light sensor, wiring, and
electronics. If the sensor does not detect the sensor-check LED, a sensor-fail alarm will occur --
the ONLINE output will change state and the ONLINE LED will begin to short flash. See Section 9.
The sensor includes 10 m of shielded three-wire electrical cable which can easily be shortened or
extended to a maximum of 50 m. Use Belden 85240 or equivalent cable (wire colors may vary).
2 m (6.6 ft)
2.5 m (8.2 ft)
3 kA
2 m (6.6 ft)
2 m (6.6 ft)
2 m (6.6 ft)
PGA-LS10
FIGURE 5. PGA-LS10 Detection Range for a 3 kA Fault.

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4.1.1 PGA-LS10 Connection
ARC-FLASH RELAY
8.00
(0.32)
3.THE PGA-LS10 SENSOR SHIPS ASSEMBLED WITH A
PLUG-IN CONNECTOR. IT MAY BE NECESSARY TO
DISCONNECT THE PLUG-IN CONNECTOR DURING
INSTALLATION.
10 m
(32.8 ft)
NOTES: 1. DIMENSIONS IN MILLIMETERS (INCHES) UNLESS OTHERWISE STATED.
2. UPTO 6 PGA-LS10 PHOTOELECTRIC POINT SENSORS WITH BUILT-IN
CIRCUIT CHECK CAN BE CONNECTED.
TERMINAL FUNCTION COLOR
TERMINAL 5V
TERMINALTX
TERMINAL RX
TERMINAL 0V
SUPPLY
CIRCUIT CHECKTRANSMIT
RECEIVE
SHIELD
RED
WHITE
YELLOW
BLACK/COPPER
NOTE 2
FIGURE 6. PGA-LS10 Connection Diagram.

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4.1.2 PGA-LS10 Installation
Point sensors include an adhesive-backed drill template for easy surface or panel-mount
installation.
PANEL SURFACE
NOTE 3
PANEL
Ø9(0.354)
PGA-LS10
DRILLTEMPLATE
SURFACE PANEL
SURFACE
Ø9(0.354)
DRILLTEMPLATE SURFACE-MOUNTED
PGA-LS10 PGA-LS10
PANEL-MOUNTED
NOTES AND INSTALLATION:
1. ALL DIMENSIONS IN MILLIMETERS (INCHES).
2. AFFIXTHE DRILL TEMPLATE WHERETHE SENSOR ISTO BE
MOUNTED.
3. MOUNTING SCREWS ARE M4 OR 8-32.
4.THE PGA-LS10 CAN BE SURFACE OR PANEL MOUNTED. SELECT
THE APPROPRIATE HOLES AND DRILLTHROUGHTHETEMPLATE.
FIGURE 7. PGA-LS10 Mounting Details.

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4.2 PGA-LS20 and PGA-LS25 Fiber-Optic Sensors with Sensor Check
The PGA-LS20 and PGA-LS25 have a 360° detection zone along the fiber’s length. A built-in LED
enables the PGR-8800 to verify the function of the light sensor, wiring, and electronics. If the
sensor does not detect the sensor-check LED, a sensor-fail alarm will occur -- the ONLINE output
will change state and the ONLINE LED will begin to short flash. See Section 9.
The PGA-LS20 and PGA-LS25 sensor have three components:
1. A fiber-optic cable, with one end covered with a black sleeve. The PGA-LS20 has 8 m
active fiber and 2 m of covered fiber. The PGA-LS25 has 5 m active fiber and 3 m of
covered fiber.
2. A transmitter with a white enclosure and a white thumb nut.
3. A receiver with a white enclosure, a black thumb nut, and an adjustment screw behind an
access hole.
Both the receiver and the transmitter connect to one PGR-8800 input using shielded three-wire
electrical cable. All three components are monitored to ensure correct operation.
4.2.1 Fiber Connection
The fiber is the light-collecting element of the PGA-LS20 and PGA-LS25. It must be installed so it
has line-of-sight to all current-carrying parts. In some cases this may be accomplished by
following the bus bars along the back wall of the cabinets.
Drill holes using the included drill template and fasten the transmitter and receiver to the cabinet
walls using rivets or screws. Connect the attached cables to the PGR-8800. The wires of the
transmitter and receiver must be connected as shown in Fig. 8.
Connect the black-sleeve-covered end to the receiver using the black thumb nut, and the white
uncovered end to the transmitter using the white thumb nut. Ensure the fiber is inserted
completely into the transmitter and receiver and the nuts are tightened. Pull gently on the cable to
verify a secure connection.
The fiber should not be sharply bent or pinched. The minimum bending radius is 5 cm.
4.2.2 Receiver Wiring Connections
Connect the red wire to 5V.
Connect the yellow wire to RX.
Connect the white wire and the shield to 0V.
4.2.3 Transmitter Wiring Connections
Connect the red wire to 5V.
Connect the white wire to TX.
Connect the shield to 0V.
The yellow wire is not used.

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4.2.4 PGA-LS20 and PGA-LS25 Connection
The sensor is shipped with the wires mounted in a terminal block. See Fig 8.
The transmitter and receiver include 10 m of shielded three-wire electrical cable which can be
shortened or extended up to 50 m. Transmitter and receiver cables can be different lengths and
must be independently shielded. Use Belden 85240 or equivalent cable (wire colors may vary).
Failure to independently shield transmitter and receiver cables can lead to an incorrect circuit
check – a faulty sensor could be falsely detected as continuous. However, if there is no sensor
fault, arc-flash detection will function normally in this condition.
SHIELD / BLACK SHIELD / BLACK
FIBER
(PGA-LS20: 8 m, 26.2 ft)
(PGA-LS25: 5 m, 16.4 ft)
NOTES: 1. DIMENSIONS IN MILLIMETERS (INCHES)
UNLESS OTHERWISE STATED.
3.THE PGA-LS20 AND PGA-LS25 SENSORS SHIP
ASSEMBLED WITH A PLUG-IN CONNECTOR. IT
MAY BE NECESSARY TO DISCONNECT THE
PLUG-IN CONNECTOR DURING INSTALLATION.
BLACK SLEEVE
(PGA-LS20: 2 m, 6.5 ft)
(PGA-LS25: 3 m, 9.8 ft)
TERMINAL FUNCTION COLOR
TERMINAL 5V
TERMINALTX
TERMINAL RX
TERMINAL 0V
SUPPLY (TRANSMITTER AND
RECEIVER)
SENSOR CHECK (TRANSMITTER)
SIGNAL (RECEIVER)
SENSOR CHECK (RECEIVER) AND
BOTH SHIELDS
RED
WHITE
YELLOW
BLACK/COPPER
2. UPTO 6 PGA-LS20 / PGA-LS25
FIBER-OPTIC SENSORS WITH BUILT-IN
CIRCUIT CHECK CAN BE CONNECTED.
Ø4.0(0.156)
MOUNTING HOLES
RECEIVER
SENSITIVITY
ADJUSTMENT
SCREW
DECREASE
SENSITIVITY
THUMB NUT
FIGURE 8. PGA-LS20 and PGA-LS25 Connection Diagram.

PGR-8800 Arc-Flash Relay Rev. 2
Pub. PGR-8800-M. December 14, 2012 • www.littelfuse.com • © 2012 Littelfuse • • 20/82
4.2.5 Fiber-Optic Sensor Adjustment
The sensor is calibrated at the factory for 60 cm of fiber in each monitored compartment. When using a
fiber-optic sensor in compartments with less than 60 cm of fiber, the sensitivity may have to be adjusted.
The sensor is unable to differentiate between 10,000 lux on 60 cm of fiber and 30,000 lux on 20 cm of fiber –
the same amount of light is transmitted through the fiber to the receiver. To achieve the desired sensitivity,
the receiver (with the black thumb nut) must be adjusted.
4.2.5.1 Sensor Adjustment for a Fiber Length other than 60 cm
To adjust for fiber length, a powerful light source of at least 100 lumen (e.g. 300 W halogen lamp) is
required. Use the following procedure to calibrate the sensor:
1. Switch the PGR-8800 to service mode by pressing the MODE button. The red SERVICE LED will
light.
2. Adjust the TRIP LEVEL setting to 1 on the PGR-8800.
3. Slowly move the lamp towards the local sensor on the front of the PGR-8800.
4. Note the distance from the lamp to the sensor when the LOCAL LED starts blinking.
5. Adjust the receiver (black thumb nut) sensitivity level to the minimum by turning the small metal
screw clockwise until it begins to click. This may be too low to detect the sensor-check signal and
may cause the related LED on the relay to flash red.
6. Place the lamp facing the fiber in the compartment closest to the transmitter end (white thumb nut) of
the fiber at the distance observed in step 4. This allows for loss along the full length of the fiber.
7. Slowly turn the metal screw on the receiver counter-clockwise until the PGR-8800 sensor-indicator
LED for that sensor changes to red. If the LED was already flashing red in step 5, it should change
to green first.
8. Adjust the TRIP LEVEL setting back to the desired position.
4.2.5.2 Sensor Adjustment in Small Compartments
If the fiber-optic sensor is used in multiple compartments of varying size, the sensor must be calibrated to the
compartment with the least fiber. If the lamp cannot be placed far enough away in the compartment to follow
the procedure in Section 4.2.5.1, the sensitivity-adjustment procedure can be modified as follows:
1. Switch the PGR-8800 to service mode by pressing the MODE button. The red SERVICE LED will
light.
2. In the compartment with the shortest fiber, measure the distance from the fiber to the lamp when the
lamp is placed at the point in the compartment where it is furthest away.
3. Set the TRIP LEVEL to 9 on the PGR-8800.
4. Place the lamp facing the local sensor on the PGR-8800 at the same distance as measured in step
2.
5. Turn the TRIP LEVEL dial on the PGR-8800 counter clockwise until the LOCAL LED starts blinking.
6. Adjust the receiver (black thumb nut) sensitivity level to minimum by turning the small metal screw
clockwise until it begins to click. This may be too low to detect the sensor-check signal and may
cause the related LED on the relay to flash red.
7. Place the lamp in the compartment closest to the transmitter end (white thumb nut) of the fiber at the
distance observed in step 2. This allows for loss along the full length of the fiber.
8. Slowly turn the metal screw on the receiver counter-clockwise until the PGR-8800 sensor-indicator
LED for that sensor changes to red. If the LED was already flashing red in step 6, it should change
to green first.
9. Adjust the TRIP LEVEL setting back to the desired position.