ABB MD21 User Manual

Soft test switch is the function
available through parameter configu-
ration. It is used to simulate module in
test position. Similar as ‘Test Switch’
function, when ‘Soft test switch’ pa-
rameter is selected, M10x switches off
current and voltage based protection
functions regardless the protection
settings. A ‘T’ symbol is displayed on
MD panel when soft test switch is se-
lected.
Under main switch OFF position,
undervoltage alarm/tip function is
suppressed to avoid unnecessary an-
nunciation
Scenario 2 Only main switch status is monitored
with no test switch hardwired
When motor is under running state (current de-
tected), if the main switch status is observed
changing from ON to OFF before a stop command
is received, M10x trips the motor with ' Main
switch status message. If the soft test switch
function is enabled during motor running, M10x
also trips the motor with ' current feedback trip'
message.
When motor is under test running state through
soft test switch function, , if main switch status is
observed changing from OFF to ON, M10x trips
the motor with ' main switch status' message. If
test switch position changes to 'OFF', M10x stops
the motor.
When motor is under stopped state, if both main
switch status ON and test switch ON are ob-
served, a trip message 'main switch status' is is-
sued.
Scenario 3 Main switch status is not monitored,
test switch is monitored
This becomes a test position feature only.
Aligned with MNS module handle design, under
test position means that the control circuit is pow-
ered up while the power circuit being
disconnected so that the control functions
testing can be conducted. Once ‘test’ position is
detected through the DI, M10x switches off
current and voltage based protection functions re-
gardless the protection settings. A ‘T’ symbol is
displayed on MD panel when ‘test’ position is
detected. Once ‘test’ position is off, all
protections restore automatically.
60 M O TO R C O NT R O L A N D P R O TE C T I O N U N I T M1 0 X U SE R G U I D E

ABB MD21 Specifications

General

Brand	ABB
Model	MD21
Category	Control Unit
Language	English