MAGNETIC TRANSFORMER BLOWING FUSES OR TRIPPING CURCUIT
If the problem is intermittent, the most common reason for the problem is the inrush current.
Inrush current is what you get when an inductance load (such as a motor, magnetic ballasted light fitting etc) is turned on. At start up the windings are cold and offer more resistance. Also the filament of the lamp in the luminare is cold, and it’s resistance is lower, so for a split second at start-up there is a low resistance on the circuit (V=IR)
In the case of fuse failure the solution is to fit a “motor start” (slow delay) fuse on the primary side of the transformer.
In the case where the circuit breaker trips it is best to check what the load on the circuit was at the time of the tripping (how many circuits were on, and what they were drawing). If the circuit breaker is running at close to capacity it is fairly probable that inrush currents at the time of switching on are taking the load over the edge, and tripping the breaker. Often just changing the breaker from the domestic 3KVA to a commercial 6KVA will solve the problem.