Instant reset time and start-up reset
<50 ms
No
Notte!
e!
• Mechanical jam protection requires that the motor running condition has been met before
tripping is possible.
9.2.1.21 Underimpedance protection (Z<; 21U)
Table. 9.2.1.21 - 418. Technical data for the underimpedance function.
Measurement inputs
Current inputs
Phase current inputs: I
L1
(A), I
L2
(B), I
L3
(C)
Voltage inputs
U
L1
, U
L2
, U
L3
U
L12
, U
L23
, U
L31
+ U
0
Calculated impedances
Phase-to-phase impedances
Phase-to-ground impedances
Positive sequence impedance
Pick-up
Pick-up setting
0.1…150.0
Ω
, setting step 0.1
Ω
Inaccuracy:
- Impedance calculation
Typically <1.0 %Z
SET
Operation time
Definite time function operating time setting
0.00…1800.00 s, setting step 0.005 s
Inaccuracy:
- Definite time (Z
M
/Z
SET
ratio <0.95)
±1.0 % or ±25 ms
Instant operation time
Start time and instant operation time (trip):
- Z
M
/Z
SET
ratio <0.95
<45 ms
Reset
Reset ratio
103 %Z
SET
Reset time setting
Inaccuracy: Reset time
0.010…150.000 s, step 0.005 s
±1.0 % or ±25 ms
Instant reset time and start-up reset
<45 ms
No
Notte!
e!
• Impedance c
Impedance calcula
alculation
tion: Voltage measurement starts from 0.5 V and current measurement
from 50 mA. In case either or both are missing, the impedance measurement is forced to
infinite.
• Ang
Angle memory
le memory: During three-phase short-circuits the angle memory is active for 0.5 seconds
in case the voltage drops below the squelch limit (0.5 V). During this 0.5 s time the
impedance is calculated based on the 1.0 V secondary voltage value and voltage angles
before the fault.
9.2.1.22 Resistance temperature detectors
Table. 9.2.1.22 - 419. Technical data of the resistance temperature detectors.
Inputs
Resistance input magnitudes
Measured temperatures measured by RTD sensors
A
AQ
Q-M257
-M257
Instruction manual
Version: 2.07
© Arcteq Relays Ltd
IM00021
495
Summary of Contents for AQ-M257
Page 1: ...AQ M257 Motor protection IED Instruction manual...
Page 2: ......
