Dielectric testing is an evaluation process performed by applying voltage to an aerial device that exceeds the normal operating voltages surrounding the working area. The purpose of the test is to determine if a component’s insulation is adequate enough to protect the user from electric shock. This testing procedure is performed on all insulated aerial devices. The manufacturer of an aerial device typically conducts dielectric testing at the end of the production process. A special device known as a dielectric tester is used to perform this type of test.
Almost all aerial devices leak a certain amount of electrical current due to a variety of different factors. This very small amount of current is considered to be safe for users of these components. Under certain conditions the insulating materials or mechanisms can breakdown and allow dangerous amounts of electrical current to come into contact with the user. This type of insulation failure can sometimes cause serious injury or death. Dielectric testing is necessary to ensure that the insulating mechanism of an aerial device will withstand voltage variations under normal operating conditions.
A dielectric test is performed before the vehicle is delivered new to a customer. An additional dielectric test is required to be performed once a year for the aerial’s yearly inspection. Also anytime an aerial’s insulated section has been repaired or any component on that unit has been replaced. Some end user’s have higher safety standards and require a test done more frequently. Check with your manufacturer or your service center to see if your aerial device is due for an inspection and dielectric test.