Nuisance trip
Nuisance trip turns up in 2 fields: electrotechnology, boilers. Here is what it means to the people in each one.
Nuisance trip in electrotechnology
Protective device opening with no real fault present, usually from bad settings, leakage or transients.
A nuisance trip is an unwanted operation of a breaker, RCD or relay when nothing needed clearing. Usual causes are cumulative earth leakage from many electronic loads on one RCD, inrush on transformer or LED circuits, harmonics heating thermal elements, poorly coordinated settings and CT wiring errors. Repeated nuisance trips tempt people to raise settings or bypass protection, which is how genuine faults later go unnoticed.
"That 30 mA RCD on the server room circuits keeps nuisance tripping, forty power supplies are leaking 22 mA before anything goes wrong."
Nuisance trip in boilers
A safety shutdown or lockout caused by a faulty or marginal device, not by a real unsafe condition.
Weak flame signals, a sticky air proving switch, a loose wire, a low-water probe coated with scale, or a gas pressure switch set too close to normal pressure all cause trips that clear on reset. They erode trust in safety devices and tempt people to jumper them out, so a good tech treats each one as a fault to fix rather than an annoyance to reset.
"Third nuisance trip on low gas pressure this week, the switch is set at 4 inches and the line drops to 4.2 at light-off."