Issue:
Pressing the purple test button on the QO or HOM Dual Function breaker does not trip the breaker, even when the Load H and Load N wires have been removed from the breaker. The power supply is only a generator, with no connection to utility company power (off-grid).
Product Line:
Circuit Breakers
Resolution:
QO and HOM DF breakers are designed and tested to be used on a system that produces good quality power, with no significant distortion in the sine wave (figure 1).
Figure 1 - Good Power Quality
If QO and HOM DF breakers are used on a system that produces poor or bad power quality (figure 2), the distortion in the sine wave can affect the electronics in the breaker, leading to a situation in which pressing the test button will not trip the breaker.
Figure 2 - Poor Power Quality
When a generator/inverter is used as the power supply feeding QO-DF or HOM-DF breakers, it is important that the generator/inverter produce good power quality. These types of generators/inverters are sometimes referred to as producing power with a "clean sine wave", "pure sine wave" or "true sine wave". To avoid the issue above in which the test button does not trip the breaker, only use generators that produce good power quality.
Pressing the purple test button on the QO or HOM Dual Function breaker does not trip the breaker, even when the Load H and Load N wires have been removed from the breaker. The power supply is only a generator, with no connection to utility company power (off-grid).
Product Line:
Circuit Breakers
Resolution:
QO and HOM DF breakers are designed and tested to be used on a system that produces good quality power, with no significant distortion in the sine wave (figure 1).
Figure 1 - Good Power Quality
If QO and HOM DF breakers are used on a system that produces poor or bad power quality (figure 2), the distortion in the sine wave can affect the electronics in the breaker, leading to a situation in which pressing the test button will not trip the breaker.
Figure 2 - Poor Power Quality
When a generator/inverter is used as the power supply feeding QO-DF or HOM-DF breakers, it is important that the generator/inverter produce good power quality. These types of generators/inverters are sometimes referred to as producing power with a "clean sine wave", "pure sine wave" or "true sine wave". To avoid the issue above in which the test button does not trip the breaker, only use generators that produce good power quality.
Released for:Schneider Electric USA
