Types of Fuse Boxes
First, before understanding the fuse box in your home, it’s important to note that a fuse box can use either breakers or fuses. A fuse box uses disposable fuses to safeguard the circuit from overloads and shorts. In order to shut off power to a particular circuit, you have to physically remove the fuse. A breaker panel, on the other hand, comes with more versatility and robustness. You can isolate a circuit by simply tripping the breaker, not to mention that the breaker will automatically trip when it detects a short or an overload – no hassle of replacing the burnt fuse after a fault.
While the majority of homes have a single “main” panel, it’s not uncommon to find homes with extra subpanels serving different floors or sections of the home. Now that you know something about an electrical panel, it’s time to delve deeper into the panels’ anatomy.
Understanding the Fuse Box Anatomy
So, what lies behind your service panels’ door? If it’s a breaker panel, you’ll see columns of circuit breaker switches with levers marked ON/OFF. Whenever the breaker trips, it falls back to the ‘OFF’ side, so you’ll simply flip it back to ‘ON’. For a fuse panel, you’ll basically have a column of fuses lying side by side. It’s difficult to identify a faulty or blown fuse except by testing it for continuity.
Now, the inner panel that surrounds the switches covers the guts of your panel’s electrical wiring and should only be touched by experienced electricians. Please remember to respect electricity and avoid unnecessary risks of shock, electrocution, or damage to your appliances. Seek the help of a licensed electrical contractor like On Time Electrical for professional panel installation, repair, and upgrades.
Types of Fuse
Standard circuits (low-voltage appliances) use plug fuses with screw-in bases. The bases can be Rejection Base (for Type-S fuses) or Edison (for type-T fuses). Now, the Edison base fuses look like light bulb bases and are found in old fuse boxes. Rejection base fuses can only work with Edison-type sockets when incorporated with an adapter base to screw and lock to the Edison socket.
So, why is a rejection base important in understanding the fuse box? As a regular homeowner, identifying different fuses can be a confusing ordeal. So, the rejection base is designed to prevent you from using the wrong fuse in a circuit. For instance, using a 20-A fuse in a circuit rated 15-A can potentially damage your equipment in the case of an overload. This is referred to as “over-fusing” and is a common cause of home fires.
Type-W fuses are general-purpose plug fuses that have become obsolete today. They are fast-acting – no time-delay fuse element. This may not be a desirable feature for certain loads like motors that draw a significant amount of current during startup.
SL and TL fuses fall under the medium-duty time-delay fuse category. They are perhaps the most common plug fuses in most homes. The major difference between SL and TL fuses is on the base. The TL fuse is designed with an Edison base while an SL fuse is made with a rejection base. Additionally, these fuses are made with a plug of heat-absorbing solder attached to the fuse element. This helps the fuse to carry a temporary circuit overload as a result of a brief surge during motor start-up.
Having shown you the basic steps in replacing a fuse, it’s paramount to take care of your own safety. Before you inspect or remove a fuse, be sure to turn off power to the area you’re working on. In fact, it’s safer to switch off the main breaker switch before you even flip-open the panel cover.
On Time Electrical is a professional electrical contractor that specializes in residential and commercial electrical services in Charlotte. Our customers are our top priority as they form part and parcel of our family, neighbors, and friends around the greater Charlotte area. Call us today for any inquiries about electrical fuse panels or for a quote.