A furnace circuit board uses two types of voltages. First is the control voltage. This always operates at 24 volts. Second is the line voltage. This is used to run the motors, and the voltage required for the line voltage depends on the unit. Typically, this is around 120 volts. With just one touch, a technician or homeowner can burn up the electrical components of a furnace. To avoid this type of incident it is important for anyone working on the furnace to discharge their self of any static electricity before working on the furnace.
Static electricity can build and burn up electrical components without any warning. Typically, when a person feels a static shock, they are feeling at least 3,000 volts of electricity. That is 20-25 times the normal capacity for that board to handle! If static discharges to the board with less than 3,000 volts, but more than the amount needed to run the board, the board can become ruined without any warning.
Grounding the electrical current out of the body is important to prevent shorting out any electrical components of the furnace. To ground the static electricity from the body, before doing any work on the electrical components, touch a metal object away from the furnace. The current will move from the body’s point of contact to the metal surface. This happens because metal is a better conductor of electricity than the human body.
Once the electricity is discharged from the body, working on the furnace is less dangerous to the electrical parts. And, if there are issues with electrical components or any other technical questions, we do offer technical support at (866) 215-3831. We have videos posted online for our most common parts, and we add more videos periodically. They can be viewed at www.hvacpartsshop.com. Feel free to give us a buzz if you need any parts for your furnace!