• Definite time operation (DT): gives the TRIP signal after a user-defined time delay regardless
of the measured or calculated voltage as long as the voltage is above the
U
set
value and
thus the pick-up element is active (independent time characteristics).
• Inverse definite minimum time (IDMT): gives the TRIP signal after a time which is in relation
to the set pick-up voltage
U
set
and the measured voltage
U
m
(dependent time
characteristics).
The IDMT function follows one of the following formulas:
Where:
•
t = operating time
•
k = time dial setting
•
U
m
= measured voltage
•
U
s
= pick-up setting
•
a = IDMT multiplier setting
The following table presents the setting parameters for the function's time characteristics.
Table. 5.4.13 - 134. Setting parameters for operating time characteristics.
Name
Range
Step
Default
Description
Delay type 1: DT
2: IDMT
-
1: DT
Selection of the delay type time counter. The selection possibilities are
dependent (IDMT, Inverse Definite Minimum Time) and independent
(DT, Definite Time) characteristics.
Definite
operating
time delay
0.000…1800.000s 0.005s 0.040s
Definite time operating delay. The setting is active and visible when DT
is the selected delay type.
When set to 0.000 s, the stage operates as instant without added delay.
When the parameter is set to 0.005...1800 s, the stage operates as
independent delayed.
Time dial
setting k
0.01…60.00s
0.01s
0.05s
The setting is active and visible when IDMT is the selected delay type.
Time dial/multiplier setting for IDMT characteristics.
IDMT
Multiplier
0.01…25.00s
0.01s
1.00s
The setting is active and visible when IDMT is the selected delay type.
IDMT time multiplier in the U
m
/U
set
power.
Table. 5.4.13 - 135. Setting parameters for reset time characteristics.
Name
Range
Step
Default
Description
Release
time delay
0.000…150.000s 0.005s 0.06s
Resetting time. Time allowed between pick-ups if the pick-up has not led
to a trip operation. During this time the START signal is held on for the
timers if the delayed pick-up release is active.
Delayed
pick-up
release
1: No
2: Yes
-
2: Yes
Resetting characteristics selection either as time-delayed or as instant
after the pick-up element is released. If activated, the START signal is
reset after a set release time delay.
Time calc
reset after
release
time
1: No
2: Yes
-
2: Yes
Operating timer resetting characteristics selection. When active, the
operating time counter is reset after a set release time if the pick-up
element is not activated during this time. When disabled, the operating
time counter is reset directly after the pick-up element reset.
A
AQ
Q-M257
-M257
Instruction manual
Version: 2.07
© Arcteq Relays Ltd
IM00021
161
Summary of Contents for AQ-M257
Page 1: ...AQ M257 Motor protection IED Instruction manual...
Page 2: ......
