Littelfuse PGR-8800 Series User Manual

Protection relays & controls, Description, Optical sensors

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Protection Relays & Controls

© 2013 Littelfuse Protection Relays & Controls

Littelfuse.com/ArcFlash

Rev: 4-F-012214

Based on Manual Rev 3-A-112913

Description

The PGR-8800 is a microprocessor-based relay that limits

arc-fault damage by detecting the light from an arc flash and

rapidly tripping. Phase-current-transformer inputs are provided

for current-constrained arc-flash protection and, when so

equipped, a programmable definite-time overcurrent function

can be enabled. An optical sensor on the PGR-8800 and

adjustable trip level reduce the chance of nuisance tripping

by setting a threshold for ambient light. Sensors, inputs, and

connections are monitored to ensure fail-safe operation. A

secondary solid-state trip circuit provides a redundant trip path.

A USB port is used for configuration and access to event logs

and graphs.

Optical Sensors

The PGR-8800 accepts both PGA-LS10 and PGA-LS20/PGA-

LS25/PGA-LS30 optical sensors, designed to collect light over

a wide angle and with high sensitivity. For fast fault location,

front-panel and sensor LED’s indicate sensor health and which

sensor detected an arc fault.

Sensor Placement

The PGR-8800 Arc-Flash Relay and sensors are easily

installed in retrofit projects and new switchgear with little or

no re-configuration. Even elaborate systems with multiple

power sources take minutes to configure using the relay’s

built-in USB interface software.
Generally, it is recommended to mount 1 or 2 sensors per

cubicle to cover all horizontal and vertical bus bars, breaker

compartments, drawers, and anywhere that there is potential

for an arc-fault. Threading a fiber-optic sensor through

the cabinets and in areas where point-sensor coverage is

uncertain results in complete coverage and an added level

of redundancy. Even if policy is to only work on de-energized

systems, all maintenance areas should be monitored to

prevent potential damage and additional cost. At least one

sensor should have visibility of an arc fault if a person blocks

the other sensor(s).

Simplified Circuit Diagram

PGA-LS10
(Point Sensor)

PGA-LS20/

PGA-LS25/

PGA-LS30

(Fiber-Optic Sensor)

PGA-1100
(Diode Logic Unit)

(Optional)

24 Vdc Battery

Backup
(Optional)

(Recommended)

(Arc-Flash Protection Relay)

PGR-8800

Trip

5-A-SECONDARY PHASE CT’s

L2

L1

A

B

C

A

B

Ordering Information

PGR-8800 SERIES (D1000)

Arc-Flash Relay

C

D

ORDERING NUMBER

COMMUNICATIONS

PGR-8800-00 (UL, CE, C-tick)

Multi-unit linking,

Modbus

®

RTU

ACCESSORIES

REQUIREMENT

PGA-LS10 (A1000)

Required*

PGA-LS20 (A2000)/

PGA-LS25 (A2000.0020)

PGA-LS30 (A2000.0030)

Required*

PGA-1100 (D1100)

Optional

Current Transformer

Recommended

*At least one sensor is required. However, the exact number of sensors for proper coverage
depends on the application.

D D D

Local

Circuit Breaker

For detailed wiring diagram, see adjacent page.

Arc-Flash Monitoring

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