Mikro N202-240AD User Manual

N202 IDMT Earth-Fault Relay User's Guide
a b c
I> I>> AUX
IDMT EARTH FAULT RELAY
0.4 0.5 0.6
f 1A
0.7
X4
1.5A
0.3
0.5A
0.8
0.2
0.9 X2
0.1
0.05 1.0 X1
0.1A 2A
I TM
TEST RESET
N202
e
d
TECHNICAL DATA

1. Current and Time Adjustments

Earth-fault Low-set Current (I>) Adjustment
- This adjustment is for setting the minumum earth-fault
current for tripping with time delay.
- The setting range is between 0.1A to 2A
Earth-fault High-set Current (I>>) Adjustment
- This adjustment is for setting the instantaneous tripping
current due to an earth-fault.
- The setting range is between 1x to 10x of the earth-fault
low-set setting value.
I>> = a x I> (a= 1 to 10)
- This high-set feature can be disabled by setting the
tripping current to in nity (∞).
Time Delay (TM) Adjustment
- The time multiplier is for setting the normal inverse
time/ current characteristic (IDMT) as according to
BS142.
- The setting range between 0.05 to 1.0 .
a - Low-set start/trip status indicator
b - High-set start/trip status indicator
c - Auxiliary power supply indicator
h
d - Test button
X6
X8
e - Trip reset button
X10
f - Earth-fault low-set adjustment
I
g
g - Delay time adjustment
h - Earth-fault high-set adjustment
f
IDMT Normal Inverse Curve

2. Light Indicators

The light indicators display the status of the system.
Indicator
AUX I> I>>
O O O
On O O
On Blink O
On On O
On O Blink
On O On

3. Push Buttons

Reset Button
- The reset button is for resetting the light indicators (I> or I>>) after an earth-fault tripping
has occured.
- To reset, press the reset button once.
Test Button
- Test button is for checking the relay operation.
- Push and hold the test button, I> and I>> LEDs start blinking then LEDs turn On and relay
contacts will be activated after 3s.

4. Trip Contacts

There are two set of tripping contacts namely, R1 and R2.
R1,R2 - Manual Reset Type
- These contacts is activated during an earth-fault trip. The contacts remain activeted
regardless of the removal of fault current. This relay can only be reset by pressing the
"RESET" button.
Status
No auxiliary power supply.
System normal mode. No tripping.
Earth-fault low-set start.
Earth-fault low-set tripped.
Earth-fault high-set start.
Earth-fault high-set tripped.