1–10 339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
SPECIFICATIONS CHAPTER 1: INTRODUCTION
Table 1-3: Current Unbalance equations
RTD (38/49T)
Pickup:...................................................................... 1 to 250
o
C in steps of 1
o
C
Pickup Hysteresis: .............................................. 2
o
C
Time Delay: ........................................................... 3 sec
Elements:................................................................ Trip and Alarm
RTD TROUBLE ALARM (38/49T)
RTD Trouble Alarm: ............................................ <-50
o
C or >250
o
C
LOAD INCREASE ALARM
Pickup Level: ......................................................... 50 to 150% FLA in steps of 1% FLA
Dropout Level:...................................................... Pickup - 2
Alarm Time Delay:.............................................. 1.00 to 60.00 s in steps of 0.01 s
Pickup Accuracy: ................................................ as per phase current inputs
Timing Accuracy:................................................ ±0.5 s or ±0.5% of total time
SHORT CIRCUIT
Pickup Level: ......................................................... 1.00 to 20.00 x CT in steps of 0.01 x CT
Dropout Level:...................................................... 97% of Pickup @ I > 1 x CT
Pickup - 0.02 x CT @ I < 1 x CT
Alarm Time Delay:.............................................. 0.00 to 60.00 s in steps of 0.01 s
Pickup Accuracy: ................................................ as per phase current inputs
Operate Time: ...................................................... <30 ms @ 60Hz (I > 2.0 x PKP), 0 ms time delay
<35 ms @ 50Hz (I > 2.0 x PKP), 0 ms time delay
Timer Accuracy:.................................................. 0 to 1 cycle
Elements:................................................................ Trip or Alarm
MECHANICAL JAM TRIP (50R)
Pickup Level: ......................................................... 1.01 to 4.50 x FLA in steps of 0.01 x FLA, blocked from start
Dropout Level:...................................................... 98% of pickup (pickup > 0.50)
Pickup - 0.01 (pickup ≤ 0.50)
Trip Time Delay: .................................................. 0.10 to 30.00 s in steps of 0.01 s
Pickup Accuracy: ................................................ as per phase current inputs
Timing Accuracy:................................................ ±0.5 s or ±0.5% of total time