Relay Function; Alarm; Pump - Siemens SITRANS LUT400 Operating Instructions Manual

Relay function

Alarm

Level
In high alarm, the alarm state becomes active when the level rises to High Level Value
ON and inactive when it falls below High Level Value OFF. In low alarm, the alarm state
becomes active when the level falls to Low Level Value ON and inactive when the level
rises above Low Level Value OFF.
In-bounds
The relay alarm becomes active if the level is inside a user-defined range.
Out-of-bounds
The relay alarm becomes active if the level is outside a user-defined range.
Temperature
In high alarm, the alarm state becomes active when the temperature rises to High
Temperature Value ON and inactive when the temperature falls below High Temperature
Value OFF. In low alarm, the alarm state becomes active when the temperature falls to
Low Temperature Value ON and inactive when the temperature rises above Low
Temperature Value OFF.
Switch (Discrete Input)
The relay alarm state associated with the discrete input becomes active when the
discrete input is in a user-defined state.
Fail-safe fault
The relay alarm state becomes active when a fault that has caused a fail-safe condition
is present. The relay alarm state becomes inactive when no faults that cause fail-safe are
present.
Flowrate
Available for LUT440 (OCM) model only.
In high alarm, the alarm state becomes active when the flowrate exceeds High Flowrate
Value ON and inactive when the flowrate falls below High Flowrate Value OFF. In low
alarm, the alarm state becomes active when the flowrate falls below Low Flowrate Value
ON and inactive when the flowrate rises above Low Flowrate Value OFF.

Pump

Setpoint - ON / OFF
If the ON setpoint is higher than the OFF setpoint, the relay operates as:
• pump down control
If the ON setpoint is lower than the OFF setpoint, the relay operates as:
• pump up control
A5E33329501 SITRANS LUT400 (HART) – OPERATING INSTRUCTIONS Page 65