Siemens SITRANS LUT400, Operating Instructions Manual

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Page 64 SITRANS LUT400 (HART) – OPERATING INSTRUCTIONS A5E33329501
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Gener
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l Oper
at
ion
•
2.4.2. LOE Timer
activates if an error condition is detected. Upon expiration of the
timer, the mA output value and the relay status default to values based on
2.4.1.
Material Level
.
• The fail-safe
2.4.1. Material Level
determines the mA output if the
2.4.2. LOE Timer
expires and the device is still in an error condition.
If fail-safe operation activates frequently, see
Diagnosing and Troubleshooting
on page
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 contact operation is NORMALLY CLOSED for alarms and NORMALLY OPEN for controls.
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).
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
Options
Default Alarm Contact Pump or Control Contact
* Normally Closed Normally Open
Normally Open Normally Closed
SITRANS LUT400
1/2
M
LEVEL
5 SAVING PARAMETERS
1 1 2 3
18.91
Relay icons:
Relay 1, 3 programmed
Relay 2 not programmed*
Relay 1 active
Relay 3 inactive
Discrete Input icons:
DI 1, 2 programmed
DI 1 off
DI 2 on
*Icon will not display for relay or DI that is not programmed.