Removing knockouts from a plastic electrical box, especially an existing one, typically involves using simple tools to break the connecting tab and push the knockout free. The method demonstrated in the referenced video uses a screwdriver and a tapping tool like pliers or a hammer.
Tools Needed
To remove a knockout using this common technique:
- Screwdriver: A flathead screwdriver is often used.
- Tapping Tool: Pliers, a hammer, or even another screwdriver can be used to tap the screwdriver handle.
Step-by-Step Guide
Follow these steps, as shown in the referenced video clip, to remove a knockout from a plastic electrical box, particularly useful for existing installations:
- Identify the Knockout: Locate the knockout you need to remove on the plastic box. You will see a thin section of plastic forming a circular or rectangular opening, held in place by one or more small plastic tabs or bridges.
- Position the Screwdriver: Place the tip of your flathead screwdriver against one of the small plastic tabs connecting the knockout to the box.
- Tap the Screwdriver: Gently tap the handle of the screwdriver with your tapping tool (pliers or hammer). The goal is to apply enough force to break the thin plastic tab.
- Break All Tabs: Repeat tapping the screwdriver on any other tabs holding the knockout in place until they are all broken.
- Push Out the Knockout: Once all the tabs are broken, the knockout should be loose. You can usually push it out easily with your finger or the screwdriver tip.
As the referenced video (Electrician Quick Tip #2 - Removing KO From an Existing Box - Note: Actual link placeholder, replace if possible) demonstrates from the 0:10 to 0:58 mark, placing the screwdriver against the tab and tapping the screwdriver handle with pliers effectively breaks the connection, allowing the knockout to come "Out. Just like that." This technique is particularly highlighted as a "Quick Tip" for "Removing KO From an Existing Box."
Why This Method is Useful
This technique is practical because it requires minimal force directly on the box itself, reducing the risk of damaging the box or its mounting when working with an already installed electrical box. It precisely targets the weak points (the tabs) designed for knockout removal.
