An electrical equipment cabinet includes a main body and at least one waterproof module. One end of a restraining line is releasably connectable to the flexible anchor line. The plate does not contact the pivot shaft, and therefore full advantage is taken of the self-lubricating property of the synthetic resin. The circuit control board is disposed within the base. When the load senses the preselected environmental condition, the sensing load alters the characteristic frequency of the ring oscillator and hence the electromagnetic radiation as emitted by the ring oscillator.