What is the purpose of a 2 prong plug?

Originally posted by: FoBoT
it can matter for certain devices

You've probably noticed that plugs often have one prong that is wider that the other. This is done so that it can be properly aligned with a receptacle. The smaller narrower pin is for the "hot" black wire and the larger wider one is for the "neutral" white wire. This is very important when it comes to wiring new appliance plugs or receptacles as it assures that the current flow is proper through that device. Of particular note are certain devices or appliances that have circuitry, such as, coffee makers, alarm clocks, computers, etc. If the hot and neutral wires are reversed, damage can occur to these appliances. Do not "clip" polarized plugs to fit into a two (2) prong receptacle or a receptacle not designed for polarized plugs.

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it can matter for certain devices

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One side is at the same potential as ground, i.e. the neutral, which is the fat side. Touching the neutral in a properly wired system will not shock you. Never defeat a polarized plug, as you may set yourself up for a shock, because the chassis may become energized. Clipping a ground is also dangerous, since this could cause a floating chassis which would not trip the breaker in case of a fault condition.

So, to answer your question, the neutral is the fat side, the narrow side is hot. That is, of course, if it was properly wired in the first place. How can you check this? If you have a multimeter, check between the fat side and ground. You should get 0V. Check from the narrow to ground - you should get 120V. Check from the narrow to fat side, you should get 120V. That would mean you have a properly wired system. You can buy small testers that plug into an outlet and with three diagnostic lights, indicate a properly wired system. Most electrical inspectors carry such devices.

One side is at the same potential as ground, i.e. the neutral, which is the fat side. Touching the neutral in a properly wired system will not shock you. Never defeat a polarized plug, as you may set yourself up for a shock, because the chassis may become energized. Clipping a ground is also dangerous, since this could cause a floating chassis which would not trip the breaker in case of a fault condition.So, to answer your question, the neutral is the fat side, the narrow side is hot. That is, of course, if it was properly wired in the first place. How can you check this? If you have a multimeter, check between the fat side and ground. You should get 0V. Check from the narrow to ground - you should get 120V. Check from the narrow to fat side, you should get 120V. That would mean you have a properly wired system. You can buy small testers that plug into an outlet and with three diagnostic lights, indicate a properly wired system. Most electrical inspectors carry such devices.

In North America, the ungrounded 2 prong plug was being replaced by grounded 3 prong outlets as early as the 1960s.

Two prong outlets had been the standard since the early 1900s, but they are simply not up to code for our modern electrical demands. Modern day appliances and the electronic devices we use need to be grounded when they are plugged in.

Although you may not have paid too much attention to them, your home will have several different electrical outlets installed including 110-volt outlets, 220-volt outlets (for electric stoves and clothes dryers), and GFCI outlets.

But if your home is 50 years old or older, for safety reasons, you might want to consider replacing any 2 prong outlets if you have them.

That said, your home may also require a wiring upgrade before switching to 3 prong outlets. For your own safety and the safety of your home and family, it is best to leave any type of electrical work to certified electricians.

In this post, our Premium Electric electricians discuss what you need to know if you are considering 2 prong plug replacements.

2 Prong Plugs Are Not Up to Code

In the USA, the electrical code was upgraded in 1962 to mandate that all electrical outlets be built with ground wire protection.

As its name suggests, a 2 prong plug is a type of socket that contains only two openings, which makes them outdated and not up to code. They have:

• 1 Neutral Wire
• 1 Hot Wire
• But NO ground wire

A ground wire is necessary to help neutralize the electrical current coming from your appliances so that it is safely dissipated into the ground. Without the ground wire, you increase the risk of damaged devices from power surges and/or injury from shocks or electrocution.

Talk to an electrician about wiring upgrades if you suspect your home’s wiring only has 2 wires and isn’t grounded.

Switching to 3 Prong Outlets

According to the Canadian National Electric Code, a 2 prong plug may still be used in homes if it is working and functioning properly. However, it is recommended that you switch to 3 prong outlets to ensure proper grounding.

There are cases when 3 prong outlets will be necessary and not just an option. For example, most heavy-duty appliances like TVs, vacuum cleaners, computers, and window-type ACs are more sensitive and should thus be plugged into three prong outlets.

How Many AMPs Does Your Home Have?

Any home built before 1965 may still have only a 30-amp or 60-amp fuse panel.

Unfortunately, 30-amp panels can only be used with 110-volt wiring, which is not enough to power many electronics in modern households such as electric stoves and clothes dryers.

Some homes also only have 100-amp service, but most modern homes now include 200-amp breakers. An electrician can assess your electrical panel and electrical usage and recommend an electrical panel upgrade, if necessary.

You might be thinking that you can simply plug your electronics into a surge protector connected into a 3-to-2 prong adapter. While this may seem like an easy fix, the truth is that it does not solve the problem since the issue remains that you still have only a 2 prong plug without any grounding.

Keeping Your Power Outlets Up to Code

Given the potential risks and dangers involved in using a 2 prong plug, it is highly recommended that you hire an electrician to help you keep your outlets up to code. Here are some of the ways you can upgrade your ungrounded plugs.

Rewire Your 2 Prong Plug

One of the best ways to solve the issue would be to have an electrician rewire a 2 prong outlet so that it is properly grounded. This is necessary if you plug in larger electronic devices like your computer or AC unit.

Replace with GFCI Outlets

Ground Fault Circuit Interrupter (GFCI) outlets must be used in areas that could potentially come into contact with water, such as kitchens, bathrooms, or the garage. GFCI outlets are designed to detect the difference in the current flowing in and out of the circuit.

Thus, if you accidentally create a short circuit, the GFCI outlet will automatically turn off the power to prevent serious injury. Take note, however, that GFCI outlets will not protect your appliances from power surges.

Retrofit a Three-Prong Receptacle

In some cases, you may be able to retrofit a three-prong receptacle into your outlet box without rewiring, as long as the outlet box itself is grounded. Fortunately, most of the boxes in older homes are attached to armored or BX cables that act like ground wires, so you will likely be able to retrofit a three-prong outlet.

Have an electrician inspect your outlet box to determine what option will be most feasible. If it does not have the necessary ground, you will need to rewire the panel. Otherwise, you can retrofit the outlet without rewiring.

As mentioned earlier, you can still use 2 prong plugs if they are working correctly. At the same time, it is not against the code to replace a faulty 2 prong outlet with another one. However, it is generally recommended to go with the other options that are listed above since these will provide you with stronger protection.

Overall, it is important to understand why a 2 prong plug is not up to code and if necessary call a professional electrician to inspect your home.

About Premium Electric

Be electricity smart and stay safe – always hire a professional electrician if you need electrical work done.

At Premium Electric, all our electricians are fully certified, bonded, and insured and service all communities within the Fraser Valley and the Greater Vancouver Regional District.

We have the knowledge and experience to help you with all your electrical needs including:

We also guarantee all completed electrical work.

When you need an electrician in Chilliwack, Mission, Abbotsford, Langley, or Surrey, or still have questions about 2 prong plug replacement, contact us online or send us an email.

Or call Premium Electric at 604-308-6195

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