Proper Electrical Grounding for Cabinets

Wood and Plastic Cabinets

• Wood and plastic are insulators, materials that resist the flow of electrical current. Grounding an insulator has no effect. The purpose of grounding anything is to provide a pathway to dissipate any charge that develops. Even if an insulator were to develop a significant charge, grounding it would not do anything. The same properties that prevent an insulator from developing a charge easily also prevent it from discharging it through a ground. You should not ground a wood or plastic cabinet.

Ground Source

• In order to ground anything, you need a ground source to connect it to. All electrical and lighting systems have a ground source. However, the ground source location within the system, color, appearance and access can vary. You should never attempt to ground anything without understanding where the ground source is for your system. Electrical systems pose a health hazard if operated or connected improperly. Once you know how to locate and access your ground source, all you have to do is attach the grounding wire from the cabinet. Turn off the electricity before grounding anything to avoid a potentially lethal shock.

Grounding Lug

• Even though cabinets are not generally required to be grounded, it is common practice for a grounding lug to be installed on many metal cabinets. The grounding lug is usually just a lug nut that is easily accessible from the outside of the cabinet. The location of the lug is going to vary between cabinets, but it is usually found somewhere on the back. The grounding lug significantly simplifies grounding the cabinet. You can solder the wire or clip it to create an attachment. Attach the grounding wire to the lug nut to ground the cabinet.

No Grounding Lug

• While a grounding lug is commonly included, it is not present in all metal cabinets. You need to create your own point to attach the grounding wire. Locate any location on one of the metal rails or surfaces of the cabinet. The location is not important because the current can easily flow to any connected metal in the cabinet to the grounding wire. You normally want to select an area on the back of the cabinet that is out of the way. Scrape off any paint or coating on the location you selected. Attach the grounding wire connected to the ground source to the bare metal by soldering it or clipping it.