Relays; General Introduction - Siemens SITRANS LUT400 Series Operating Instructions Manual

2.4.2. LOE Timer
•
timer, the mA output value and the relay status default to values based on
Material Level
• The fail-safe
expires and the device is still in an error condition.
If fail-safe operation activates frequently, see
231.

Relays

Relays are the primary controls of external devices such as pumps or alarms. The
SITRANS LUT400 comes with extensive control and alarm functions described below.

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.
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.
Mode
alarm
pump
miscellaneous
Relay contact operation is NORMALLY CLOSED for alarms and NORMALLY OPEN for controls.
Options
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).
Page 64 SITRANS LUT400 (HART) – OPERATING INSTRUCTIONS
activates if an error condition is detected. Upon expiration of the
.
2.4. 1 . Material Level
determines the mA output if the
SITRANS LUT400
LEVEL
18.91
1 3
5 SAVING PARAMETERS
Function (in normal state)
alarm ON = LCD icon ON = relay coil de-energized
pump ON = LCD icon ON = relay coil energized
contact closed = LCD icon ON = relay coil energized
Default Alarm Contact
* Normally Closed
Normally Open
Diagnosing and Troubleshooting
1/2
1 2
Pump or Control Contact
Normally Open
Normally Closed
2.4.1.
2.4.2. LOE Timer
on page
M
Discrete Input icons:
DI 1, 2 programmed
DI 1 off
DI 2 on
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