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54-610 Thermatel Model TD1/TD2 Flow Level Switch
2.5.2 LED Operation
TD1
– Two LEDs (Green & Red)
• Green LED glows when power is on.
• Red LED, glows when an alarm condition exists. The
LED operation is independent of relay operation.
• The red LED will blink rapidly if the switch detects a fault.
It will blink slowly during initial power-on.
TD2
– Four LEDs (Red, Yellow, & 2 Green)
LEDs indicate alarm status and fault indication. The LED
operation is independent of relay operation.
• Red LED glows when an alarm condition exists. It will
blink if the switch detects a fault.
• Yellow LED glows when approaching an alarm condition
• Green LEDs glow as the actual condition is further away
from the alarm set point. This represents a safe mode.
2.5.3 LED Initialization
The TD1/TD2 has an initializing period to allow the
sensor to heat up.
TD1 – The red LED will blink slowly during the initial-
ization period.
TD2 – All LEDs will turn on then individually turn off.
When complete the TD2 will resume normal operation.
2.5.4 Time delay (TD2 only)
Turning the time delay potentiometer clockwise increases
response time. This adjustment adds time delay in addi-
tion to the sensor response time. Generally this is set to
full counterclockwise position unless additional time delay
is required due to pulsating flow, turbulence, or splashing.
If time delay is used, the red alarm LED will first illumi-
nate when an alarm condition occurs, the relay activation
will occur after the appropriate time delay. Time delay
occurs while going into alarm. There is no time delay
(other than sensor response time) coming out of alarm.
