Overview .............................................................................................................................................. 1 - 1

Description of the 845 Transformer Protection Relay .................................................... 1 - 2

Security Overview ............................................................................................................................ 1 - 6

845 Order Codes............................................................................................................................... 1 - 8

Specifications...................................................................................................................................1 - 10

Protection................................................................................................................................................... 1 - 10

Control ......................................................................................................................................................... 1 - 17

Monitoring.................................................................................................................................................. 1 - 17

Recording ................................................................................................................................................... 1 - 19

User-Programmable Elements ........................................................................................................ 1 - 19

Metering...................................................................................................................................................... 1 - 20

Inputs ........................................................................................................................................................... 1 - 22

Outputs........................................................................................................................................................ 1 - 23

Power Supply............................................................................................................................................ 1 - 24

Communications .................................................................................................................................... 1 - 24

Testing & Certification.......................................................................................................................... 1 - 25

Physical ....................................................................................................................................................... 1 - 26

Environmental.......................................................................................................................................... 1 - 26

Cautions and Warnings ..............................................................................................................1 - 26

Safety words and definitions ............................................................................................................ 1 - 26

General Cautions and Warnings..................................................................................................... 1 - 27

Must-read Information ................................................................................................................1 - 28

For Further Assistance.................................................................................................................1 - 29

Mechanical Installation ................................................................................................................. 2 - 1

Product Identification..............................................................................................................................2 - 1

Dimensions...................................................................................................................................................2 - 1

Mounting .......................................................................................................................................................2 - 2

Standard Panel Mount.............................................................................................................................2 - 3

Draw-out Unit Withdrawal and Insertion ......................................................................................2 - 4

Removable Power Supply......................................................................................................................2 - 5

Removable Magnetic Module..............................................................................................................2 - 6

Electrical Installation ...................................................................................................................... 2 - 7

Terminal Identification ......................................................................................................................... 2 - 12

Wire Size......................................................................................................................................................2 - 16

Phase Sequence and Transformer Polarity ............................................................................... 2 - 16

Ground CT Inputs.................................................................................................................................... 2 - 17

Voltage Inputs.......................................................................................................................................... 2 - 17

Restricted Earth Fault Inputs ............................................................................................................ 2 - 18

Zero-Sequence CT Installation......................................................................................................... 2 - 18

Control Power........................................................................................................................................... 2 - 19

Contact Inputs ......................................................................................................................................... 2 - 20

Output Relays........................................................................................................................................... 2 - 20

Serial Communications ....................................................................................................................... 2 - 22

IRIG-B ........................................................................................................................................................... 2 - 23

Front Control Panel Interface ..................................................................................................... 3 - 2

845 Graphical Display Pages..............................................................................................................3 - 2

Working with Graphical Display Pages ...........................................................................................3 - 3

LED Status Indicators ..............................................................................................................................3 - 6

TOC-I