Discharge Stick (100kVDC)
Discharge and grounding sticks are vital parts of high-voltage safety practices. The sticks have been specifically designed for high-voltage testing in the field or laboratory. Depending on the application, only the ground stick may be used or a discharge and ground stick may have to be used.
AC Sources
AC high voltage sources such as high voltage transformers and resonant test systems are typically grounded with ground sticks appropriate for their physical size and output voltage. Phenix Technologies’ Model GS100-2 ground stick is ideally suited for this use. The generous length and the hand guard insure that the operator is distant when the high-voltage output is grounded. The Model GS100-2 or GS160-2 is equipped with a hook that attaches to the high-voltage electrode of the source. The ground cable is equipped with an alligator clamp for connection to the earth's ground.
DC Sources
When testing with DC, extra caution has to be taken in order to dissipate the stored energy in capacitive test objects such as cables, motors and transformers. These test objects have the capability to store large amounts of energy long after the high voltage is turned off. High Voltage DC sources require two different sticks. The first stick typically used is called a discharge stick. The discharge stick removes the stored energy through a resistor connected to the ground. In this way, the discharge happens over time and not instantaneously and potentially dangerously as with a direct short (ground stick). In addition, this limits transients and or traveling waves that could damage objects under test. First, the stored energy is minimized; typically by watching the output voltmeter return close to zero. Next, the ground stick is applied to remove any remaining charge and directly connect the high-voltage source at the test object to the ground. Discharge sticks are not considered grounding devices due to the resistance in the circuit. It should be noted that discharge sticks have three ratings that need to be considered for safe operation: the instantaneous energy (kilojoule) rating, the continuous operating wattage of the discharge resistor, and the maximum discharge voltage rating. The Model DS100-2 is equipped with a hook that attaches to the high-voltage electrode of the source. The ground cable is equipped with an alligator clamp for connection to the earth's ground.
General High Voltage Safety Guidelines
Note that the following information is for reference only and that there are operating guides for national and international safety standards that specify detailed safety requirements. It is the user’s responsibility to verify that Phenix Technologies’ products are applicable to these standards.
Any high-voltage source that does not have a visible ground wire or ground device attached (high voltage output shorted to ground) is generally considered live and dangerous. It is established practice never to touch or come close to the high voltage source when the source is not grounded. Ground Sticks are one of the accepted methods to apply a temporary ground to these sources. For permanent grounds bolted grounding cables are typically used.