GE 845 User Manual

CHAPTER 1: INTRODUCTION SPECIFICATIONS
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL 1–19
DEMAND
Measured Values:................................................Phase A/B/C present and maximum current
Measurement Type:...........................................Thermal Exponential, 90% response time (programmed): 5,
10, 15, 20, 30 minutes
Block Interval / Rolling Demand, time interval (programmed):
5, 10, 15, 20, 30 minutes
Current Pickup Level:.........................................10 to 10000 in steps of 1 A
Dropout Level: ......................................................96-98% of Pickup level
Level Accuracy:....................................................± 2%
WINDING HOTTEST-SPOT
Operating Quantity:...........................................Computed temperature in ºC
Pickup Level:..........................................................50 to 300ºC in steps of ºC (122ºF to 572ºF in steps of 1ºF)
Dropout Level: ......................................................1ºC below pickup
Pickup Delay: ........................................................0 to 60000 minutes in steps of 1 min
AGING ACCELERATION FACTOR
Operating Quantity:...........................................Computed Aging Acceleration Factor, per-unit
Pickup Level:..........................................................1 pu to 10 pu in steps of 0.1 pu
Pickup Delay: ........................................................0 to 60000 minutes in step of 1 min
XFMR LOSS OF LIFE
Operating Quantity:...........................................Computed Accumulated Transformer Loss of Life, hours
Pickup Level:..........................................................0 to 300000 hours in steps of 1 hour
TAP CHANGER FAILURE
Operating Parameter:.......................................Tap Changer Position
Time Delay:............................................................0.00 to 600.00 s
Timer Accuracy: ..................................................±3% of delay setting or ±2 cycles (whichever is greater) from
pickup to operate
HARMONIC DETECTION
Operating Parameter:.......................................Current 2
nd
, 3
rd
, 4
th
, 5
th
harmonic or THD per phase
Timer Accuracy: ..................................................Harmonics: ±3% of delay setting or ±1/4 cycle (whichever is
greater) from pickup to operate
THD: ±3% of delay setting or ±3 cycles (whichever is greater)
from pickup to operate
Recording
TRANSIENT RECORDER
Default AC Channels:......................................... currents + 4 voltages
Configurable Channels: ...................................16 analog and 64 digital channels
Sampling Rate:.....................................................128/c, 64/c, 32/c, 16/c, 8/c
Trigger Source:.....................................................Any element pickup, dropout or operate, digital input or
output change of state, FlexLogic operand
Trigger Position:...................................................0 to 100%
Storage Capability: ............................................Non-volatile memory
EVENT DATA
Number of Records:...........................................1024 (matches the existing Event Recorder)
Data Storage:........................................................Non-volatile memory
Time-tag Accuracy: ...........................................One microsecond
Settings:...................................................................64 Configurable FlexAnalog parameters,
Event Selector
Actuals:....................................................................Selected Event Number,
Timestamp of Selected Event,
Cause of Selected Event,
64 Configurable FlexAnalog values
Commands: ...........................................................None (using existing Clear Event Recorder)

GE 845 Specifications

General

Brand	GE
Model	845
Category	Protection Device
Language	English