ST-94112N page 4 of 4
BASIC OPERATION
ST8
1. Apply power to the ST8 TATTLETALE®(terminals13 and 14).
2. The “POWER ON” and “RUN” LED light will switch On. The
“POWER ON” LED indicates power has been applied to the ST8.
The “RUN” LED indicates the internal relay is in the
operating mode.
3. The lockout time delay during startup will begintiming. Sensors with
lockout time delay selected (see Setting Lockout Switches below) will
not trip alarm or shutdown circuit until time delay times out (25-35
seconds). If lockout switches are not set there will not be a time
delay during startup.
4. The 8 Red shutdown LEDs are for shutdown indication (see
Figure 6).
5. When a shutdown signal is received from a SWICHGAGE®, the
shutdown LED will light and internal shutdown relay will switch to
activate a shutdown device (see Typical Wiring page 3). All other
shutdown sensor inputs are locked out.
6. Shutdown LED will remain on even if conditions return to normal.
To clear the LED, power must be removed or push button reset
is operated.
Setting Lockout Switches
Lockout switches allow you to lockout shutdown/alarm sensors during
startup. For instance, on a pressure SWICHGAGE®, the lockout time
delay allows time for pressure to build up thus lifting the pointer off the
low limit contact. If the lockout time delay is not set the TATTLE-
TALE®will initiate the shutdown/alarm sequence.
Each sensor input on the ST8 has a lockout
time delay at startup with a length of 25 to
35 seconds.
1. Locate the lockoutswitches on back
of the unit (see Figure 7).
2. Determine which sensors you wish
to lock out. Switch the corresponding
sensor lockout switch “ON”. A SEN-
SOR CAN BE LOCKED-OUT
ONLY WHEN ITS LOCKOUT
SWITCH IS SWITCHED “ON”.
3. Remove the jumper between terminals 12 and 13. This will activate
the time delay. If this jumper is not removed the lockout time delay
will not function.
