3.1 Verify the Timing Contact Channels (Hardware Check)
Short-circuit the timing channel A1–N1 using a jumper wire.
Observe the timing status indicator on the instrument display.
Expected behavior:
HandyWhen A1 and N1 are shorted, the indicator should become solid, indicating a closed contact.
HandyWhen the jumper is removed, the indicator should become hollow, indicating an open contact.
If the indicator responds correctly, the timing channel is functioning properly.
If a timing channel is defective, use another available channel instead. Since the tester's six or twelve timing channels operate independently, a damaged channel will not affect the others.
When convenient, return the instrument to the manufacturer for repair.
3.2 Verify the Test Duration
Ensure that the configured test duration is sufficiently longer than the actual opening or closing time of the circuit breaker.
A proper test duration allows the instrument to capture:
HandyContact timing
HandyTravel curve
HandyCurrent curve
For most applications, the factory default test duration is recommended.
If the circuit breaker has a relatively long operating time, increase the test duration accordingly.
Note: The Closing Test Time refers to both the duration of the closing control pulse output and the data acquisition period. The same principle applies to the opening test.
3.3 Verify the External Test Circuit
During a standard mechanical characteristic test, one or both grounding switches are typically opened.
If the tester hardware and software settings are correct but timing data is still unavailable, inspect the following:
HandyTest leads
HandyHigh-altitude test clamps
HandyContact resistance between the test leads and the breaker terminals
HandyQuality of electrical connections
If one grounding switch remains closed and is used as the common return path (N1 grounded), oxidation of the grounding switch contacts may increase circuit resistance.
In this situation, connect the N1 lead directly to the conductor between the grounding switch and the circuit breaker to bypass the high-resistance connection and restore normal measurements.
