User guide

REV 3 DIGITMR USER’S MANUAL
16
3.1.4. External Trigger Input Connections
The External Trigger Mode can be used to start recording when the DigiTMR senses a voltage. A
typical application for the External Trigger Mode is to time a circuit breaker in a close operation
and to start timing only when the close coil is energized, thus bypassing the 52X relay delay
time.
Since the 52X relay carries the close coil current, the initiate cable must be connected to the
close terminal as shown in Figure 4. The DigiTMR will energize the 52X relay to start the close
operation and will then start timing when it senses the voltage across the closing coil. Please
see Figure 7 for a typical test connection. Another application for the External Trigger Mode is
to start timing the breaker when the user trips or closes the breaker remotely.
NOTES
• Minimum trigger voltage is set at 30 Vac/dc. Maximum continuous voltage is set
at 300 Vac/dc.
• Different trigger voltages can be set at the factory based on specific user
requests.
• The DigiTMR will start looking for the external trigger voltage when the
message “AWAITING TRIGGER…” is shown on the LCD. If the external trigger
voltage is not sensed by the DigiTMR within ten seconds after the initiate
sequence has begun, the DigiTMR will return to the main menu.
Figure 7. External Trigger Cable Connections