Avoiding Nuisance Tripping

It is possible for circuit breakers to interrupt ("trip") the supply even when there is no dangerous condition, though you should always confirm that there is no dangerous condition before reconnecting the supply. For example, a spilled drink, exposed metal in a cable, or a faulty piece of equipment. There are a number of typical conditions that lead to nuisance tripping described below.

Inrush Current

A device's actual consumption can spike or peak much higher than its rated or expected consumption for very short amounts of time, for example when it is first turned on, it will draw a large amount of current for a very short time, known as "inrush current". If you are operating close to your maximum supply rating, this can cause breakers to trip or fuses to blow. This is worsened if many devies are turned on at the same time.

Mitigation

Stagger turning equipment on, so that each piece of equipment can draw a higher-than-normal amount of current for a short time without tripping breakers or blowing fuses.

Earth Leakage

Earth leakage circuit breakers described above save lives, but they can also trip when there are no dangerous conditions. This is caused by a large number of switch-mode power supplies (SMPSUs) each leaking a small amount of current to earth, which in combination is higher than the threshold that the ELCB allows. Unfortunately, SMPSUs are used by a huge number of electronics, including consoles, gaming computers, monitors, TVs and phone chargers.

To illustrate the problem, each SMPSU will leak approximately 1 milliamp (mA) of current to earth, and commonly ELCBs trip at 30mA. This means that once you have ~30 SMPSUs connected, e.g. 15 computers and 15 screens, the ELCB is at risk of tripping, even though no-one is getting an electric shock. Typically in practice, the breaker will trip after 15-20 devices.

Mitigation

To mitigate against this, whilst still providing protection against electric shocks, you can use several ELCBs, making sure that no more than approximately 20 devices with SMPSUs are connected to each 30mA ELCB. However, this may not be possible if the ELCB is part of your distribution board, and as a result you will need an electrician to make changes to the distribution board.

High Ambient Temperature

Thermal magnetic breakers can trip in conditions of high ambient temperature, which can easily happen in extension Reels with this kind of breaker.

Mitigation

Avoid direct sunlight shining on breakers, ensure good airflow around them, and apply additional air cooling to them if possible.