The VON Model BCM-44B is a state of the art insulated boom current monitor designed for continuous operation during bare hand work on aerial devices wired to allow continuity checks on each test circuit. This requires two wires to each pickup location. The six conductor input allows up to three test circuits. Current is monitored with all test circuits in parallel except when searching for a source of abnormally high leakage. Then the current can be measured for each of the three test circuits individually. The monitor has less than a .5 volt drop so that errors due to the capacitive coupling between the aerial lifts test circuits and chassis ground are eliminated. The monitor is designed so that the internal horn will sound if any lead in the measurement circuits touch ground. This sometimes occurs when the shielded cable to the test connector is pinched at the boom knuckle. A front panel mounted switch is provided to select up to six current setpoints at which the alarm will sound. Five setpoints are standard. Each of the three test circuits can be checked individually for continuity using the push-button provided. This allows the operator to verify that the internal wiring of each test circuit in the aerial lift has not broken during the movement from one location to another.
It is especially important to check each aerial lift to insure that the test circuits are actually connected so that all paths of current across the insulated section are being measured. If all possible leakage paths across the insulated section are not included in the test circuits then the current readings provided by this monitor have little meaning.
The Von Corporation, 1038 Lomb Avenue, SW Post Office Box 110096, Birmingham, AL 35211. Tel: 205-788-2437; Fax: 205-780-4015.