Parts Catalog
Circuit Breakers, Contactors & Protection
What trips, switches, and protects inside a switchboard — from miniature circuit breakers up to main air circuit breakers, plus the contactors and protection relays wired around them.
MCCB (Moulded-Case Circuit Breaker)
Feeder and motor protection on a marine switchboard. When one trips without an obvious overload behind it, checking the thermal-magnetic trip unit's calibration is the first move.
View detailsMCB (Miniature Circuit Breaker)
Protects control and lighting circuits — often the oldest breaker on a panel, and the first thing worth checking on a dead lighting circuit.
View detailsACB (Air Circuit Breaker)
Sits on the main switchboard behind the generator or shore supply, where a fault risks a full blackout. Given the stakes, these get diagnosed carefully on site — never swapped on a hunch.
View detailsMagnetic Contactor
Switches motor and generator circuits under load. Pitted or welded contacts are the usual failure, often from a coil that's been chattering rather than a single overload event.
View detailsThermal Overload Relay
Sits on a motor starter and trips before winding damage happens. An early trip usually points to a miscalibrated relay, and recalibrating it is the first thing we try.
View detailsMotor Protection Relay
Covers overload, phase loss, and stall conditions in one unit — useful where a simple thermal relay isn't catching an intermittent single-phase fault before it burns a winding.
View detailsGenerator Protection Relay
Guards a generator's safety circuits — over/under voltage, over/under frequency, reverse power — and is one of the first places we look when a set trips on load acceptance.
View detailsEarth Fault Relay / ELCB
Trips on leakage current before it becomes a shock or fire risk. Sensitivity settings drift more than the relay itself fails outright, so recalibration solves most 'nuisance' trips.
View detailsInsulation Monitoring Device (IMD)
Continuously watches insulation resistance on an IT (ungrounded) marine power system — exactly the kind of monitoring you can't retrofit after a fault's already happened.
View detailsHRC Fuse (Marine-Rated)
High rupture capacity fuse protection for control and power circuits. Cheap to replace, but a fuse that's blown more than once in the same spot usually means an upstream fault worth tracing.
View detailsIsolator / Disconnect Switch
A manual load-break switch for isolating a circuit during maintenance — simple, but a worn contact inside one is a genuine safety issue if it doesn't fully isolate.
View detailsAutomatic Transfer Switch (ATS)
Switches load between two supplies automatically on failure of the primary. The transfer logic and contactors are what we check first when a switch fails to transfer, or transfers when it shouldn't.
View details