LD-DS-69A

DS-69A Drill Stop: Prevents cutting of rebar and conduit.

Features

• The DS-69A prevents accidental cutting of reinforcing bar and conduit by turning off power to the drilling unit when grounded metal is encountered.
• The DS-69A provides operator safety. The job of detecting concealed rebar and conduit necessitates electrical isolation of the drilling unit from its conventional grounding connection. The DS-69A provides fast and reliable solid state switching to reestablish the ground connection in cases where an external, energized line is encountered or where the drill motor is shorted to the drill case.
• The DS-69A may be used in a concealed metal detect "Off" mode.

The DS-69A Drill Stop is intended primarily to sense the presence of grounded metal in concrete and prevent damage to this metal by terminating power to the drill motor when it is detected. Since this function necessitates electrical isolation of the drill bit, tool casing and tool ground line, additional switching circuitry is needed to provide operator safety in cases where leakage current from the motor may be present or where energized lines may be encountered during the drilling operation. The DS-69A provides this protection by switching voltage potentials in excess of 10 volts to a low impedance, high current capacity ground path. This switching is accomplished in a maximum of 5 microseconds. Voltages of up to 600V and currents of up to 110 Amps RMS continuous (1000 Amps peak one cycle, nonrepetitive surge current) are switched to ground. Voltages and currents in excess of these values will also be switched to ground but may result in failure of the switching circuitry in the closed (conducting to ground) condition. Such failure will preclude resetting of the unit for continued operation. Information regarding the upper bound current conducting capacity of the switching circuitry in a failed (conducting to ground) condition is unavailable.

The DS-69A may also be operated in a concealed metal detect "Off" mode, i.e. the drill unit will contunue to opertate after grounded metal has been detected.