Operating Procedures
RFD-200 S2™
12
4.3 Use RFD-200 S2 Timer to Test a Circuit Breaker Response Time
The following steps set the RFD-200 S2 timer to measure the opening time of a circuit
breaker. The timer will start when the RFD-200 S2 detects the voltage being applied to
the circuit breaker trip coil.
The timer will stop when the RFD-200 S2 detects the circuit breaker contact has opened.
1. Connect the
TIMER START
input to circuit breaker coil terminals.
2. Select
WET INPUT
in the timer start-box. The
WET
LED shall light.
3. Connect the
TIMER STOP
input to the circuit breaker dry contact
4. Select
DRY INPUT
for the timer stop-box. The
DRY
LED shall light.
5. Turn the
OUTPUT CONTROL
knob to zero.
5. Select
START-ON
in the Control Box.
6. Open the circuit breaker.
7. The RFD-200 S2 timer will start when the circuit breaker coil voltage is detected and
will stop when the circuit breaker contact has opened.
8. Observe the LCD display and
TEST COMPLETE
LED are flashing.
9. Observe the time in milliseconds and the cycles on the LCD readout.
Figure 10 Typical Circuit Breaker Timing Connection
