40
1MRS 752264-MUM
Motor Protection Relay
Operator’s Manual
REM 610
4.3.
Measurements verification
As most of the protection functions in the protection relay are based on the phase
currents and earth-fault current measured by the relay, it is important to verify that
the relay is measuring proper values. This verification can be performed by
examining the current readings on the display while injecting a pure sinusodial
current into the current input. If the reading on the display corresponds to the
calculated value, taking the relay accuracy and display resolution into account, the
relay is measuring proper values.
Rated current for the energizing input being verified is shown on the relay label
under the lower handle of the relay.
The protected unit scaling factor, used for motor full load current I
n
compensation,
has to be taken into account when verifying phase currents measured by the relay.
The value to be shown on the display is calculated as follows:
When verifying the earth-fault current measured by the relay, the value to be shown
on the display is calculated as follows:
4.4.
Function test
This section describes how the signal routing from protection functions
to, and
operation of, the output contacts in the relay can be tested.
The internal signals are routed to the output contacts according to the SGR
switchgroups.
The test mode is accessible via
FUNCTION TEST/DI
under
CONFIGURATION
in the HMI menu. In the test mode, all internal signals from the different protection
stages can be activated one by one, the self-supervision included.
1. Press an arrow button to access the main menu.
2. Use
or
to
select
CONFIGURATION
in the main menu and press
. The
cursor is at the first menu item,
FUNCTION
TEST/DI
. Press
again to enter
the test menu.
3. The cursor is at the first parameter,
FUNC.TEST
. Press
to enter the test
mode and give the password if required.
4. Select the wanted signal with
or
and press
to activate the signal. The
signal will remain active for as long as
remains pressed.
5. Repeat the previous step to test other signals.
6. To leave the test mode, press
.
7. Press
again to return the display to the idle mode.
Value on LCD
I
n
( )
Injected current
energizing input rated current
---------------------------------------------------------------------------------------
PU scalin
×
g factor
=
Value on LCD
%
( )
Injected current
energizing input rated current
---------------------------------------------------------------------------------------
100
×
%
=
