Siemens SITRANS LUT400 - General Introduction

General Operation
7.2 Relays
SITRANS LUT400
Operating Instructions, 07/2019, A5E33329501-AC
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7.2.1 General introduction
Three relays are provided on the SITRANS LUT400. Each relay may be independently
assigned to one function (one or more functions for alarms), and has a corresponding status
icon on the LCD.
①
Relay icons:
Relay 1, 3 programmed
Relay 2 not programmed*
Relay 1 active
Relay 3 inactive
* Icon will not display for relay or DI that is not programmed.
②
Discrete Input icons:
DI 1, 2 programmed
DI 1 off
DI 2 on
Mode
Function (in normal state)
alarm
alarm ON = LCD icon ON = relay coil de-energized
pump
pump ON = LCD icon ON = relay coil energized
miscellaneous
contact closed = LCD icon ON = relay coil energized
Relay contact operation is NORMALLY CLOSED for alarms and NORMALLY OPEN for
controls.
Options
Default
Alarm Contact
Pump or Control Contact
*
Normally Closed
Normally Open
Normally Open
Normally Closed
* Icon will not display for relay or DI that is not programmed.
In software, all relays are programmed the same way, with ON setpoints indicating when to
change the relay contact state (open or closed). Some parameters allow the reversal of the
operation so that relay contacts can be NORMALLY CLOSED or NORMALLY OPEN (for
example, when assigned to an alarm).