/ Field knowledge · NEC 100 · Sparky Edition
“The breaker trips” is not a diagnosis.
NEC Article 100: “the breaker trips” is an event, not a diagnosis. Overcurrent, overload, short circuit, and ground fault are different conditions. Do not upsize the breaker to keep the RTU running.
Educational 2026 NEC Article 100 terminology. Confirm the adopted edition. This is not a conductor size, motor-protection selection, or trip setting. If there is smoke, fire, arcing, shock, or immediate danger, stay clear and contact emergency services. Do not approach equipment for a better photograph.
- Overcurrent is the umbrella: current that exceeds the relevant equipment rating or conductor ampacity.
- Overload is excessive loading along the intended circuit path long enough to overheat.
- Short circuit is an unintended connection between points at different potentials.
- Ground fault is an unintended connection involving an ungrounded conductor and normally non-current-carrying conductive material or earth.
A ground fault may not trip an ordinary breaker. Some ground-fault currents are too small to operate conventional overload/short-circuit protection promptly. GFCI protection for people and equipment ground-fault protection have different purposes; neither is an ordinary breaker, and they are not each other.
Reset, bypass, upsize
Do not repeatedly reset a tripping device, bypass a safety function, increase its rating, or alter trip settings just to keep equipment operating. A motor overload device, a branch-circuit protective device, and ground-fault protection do not perform identical jobs. “Trips when cooling starts” is evidence. “Bad breaker” is an unverified conclusion.
Source: Sparky overcurrent · SCCR: fault current · continuous load: demand/duty.
What to send
Equipment ID, when it trips, what changed (new load, water, sequence), and the one-line if it exists. Do not open equipment.
If the breaker trips when cooling starts
Send the event record, not a parts list. Masterbuild will say whether this is even an overload conversation — or the team is about to upsize the wrong device.
Send Project Background+1 (786) 398-6940 · osmany.portal@masterbuildconsulting.com
Masterbuild provides engineering services under a written scope. Nothing on this page is project-specific engineering advice, a code interpretation for your project, or a representation about permit approval. Sparky Edition uses the 2026 NEC as model-code education. Confirm the adopted edition. Field observations do not establish electrical safety; only qualified personnel using required safe-work procedures should access electrical equipment.