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When something trips
Short circuit, overload, magnetic trip, blown fuse, overloaded supply — what each alarm is telling you and what to change.
A protection that operates is not a bug in your circuit. It is the circuit telling you what a real one would have done. Each alarm names a different physical cause.
SHORT CIRCUIT! — Check your connection
Two points at different potential are joined with nothing in between: line onto neutral, L1 onto L2, or a load bridged by a wire that should not be there.
Look for it where you last drew. The most common causes are a wire finished on the wrong terminal by one grid square, and a junction dropped onto a run that was not the one you meant to tap.
OVERLOAD! — Thermal trip
The slow protection. Current stayed above the rating long enough to heat the bimetal, and the thermal relay opened.
This is not an instantaneous fault: it accumulates, exactly as it does in the cabinet. It usually means the motor is rated above the protection setting, or the protection was set below the motor's actual current.
MAGNETIC TRIP! — Current > curve threshold
The fast protection inside a circuit breaker, the one that reacts in milliseconds to a current far above rating.
Thermal answers "too much, for too long". Magnetic answers "far too much, right now" — which in practice means a short circuit downstream of that breaker.
FUSE BLOWN! — Replace the cartridge
A fuse is single-use. Once blown, its cartridge has to be replaced before that branch can conduct again — a breaker you reset, a fuse you change.
If it blows again immediately, the fault is still in the circuit; the cartridge was the messenger.
The class of the fuse matters
A gG fuse covers the full range: it melts on overload as well as on short circuit, and it is the one for cables, sockets and lighting. Motor circuits use a different class because the starting current of a motor is, briefly, an overload by any other measure.
SUPPLY OVERLOADED! — Output shut down — reduce the load
Not a protection tripping — the power supply itself giving up. You are drawing more from that 24 V unit than it can deliver, so it has shut its output down.
Count what hangs on it: coils, pilot lights, PLC inputs, sensors. The answer is either fewer consumers on that supply or a bigger one.
NO LINK TO THE PLC — Outputs frozen — check the bridge
Only when a real CPU is driving the circuit through the UnifCAD bridge. The connection dropped, so the outputs are held at their last known state rather than being invented.
Check that the bridge application is running and still connected to the CPU. While the badge shows REMOTE, the logic you are watching is not UnifCAD's — it is the real controller's.