The main difference between earthed and unearthed sockets is the number of connections - earthed sockets have three holes while unearthed sockets have two. The third hole on earthed sockets connects to a protective conductor that diverts dangerous current in the event of a fault, providing significantly better electrical safety in the home. This difference affects which appliances you can safely plug in and how protected you are from electric shocks.
What is the difference between a grounded and an ungrounded outlet?
Earthed sockets have three connection points - two for power supply and one for earthing, while ungrounded sockets have only two holes for phase and neutral. The third hole on earthed sockets is connected to a protective conductor that diverts fault current directly to earth in the event of a short circuit or insulation fault.
Visually, you can recognize the difference by counting the number of holes. Earthed sockets always have three holes arranged in a triangle or line, while unearthed sockets only have two holes. Earthed sockets are also slightly thicker and more robust in construction as they have to handle the extra earth conductor.
Functionally, the difference means that earthed sockets provide active protection against electric shock. When you plug an appliance into an earthed socket, the metal parts of the appliance are automatically connected to earth through the protective conductor. If the insulation of the appliance is broken and live parts come into contact with the metal casing, the current is safely conducted away to earth instead of through your body.
Why is earthing important for electrical safety in the home?
Earthing protects you from life-threatening electric shocks by creating a safe path for fault current to be diverted away from electrical appliances. When the insulation of an appliance is damaged, the grounding system automatically diverts the hazardous current to earth, tripping fuses or RCDs that break the circuit.
Utan jordning riskerar du att bli en del av strömkretsen om du rör vid en defekt apparat. Din kropp blir då den väg strömmen tar för att nå jord, vilket kan orsaka allvarliga skador eller dödsfall. Jordning fungerar som en elektrisk ”säkerhetsventil” som aktiveras omedelbart när något går fel.
Modern Swedish electrical regulations require earthing in all new installations according to SS 436 40 00. This means that all sockets in newly built houses and during renovations must be earthed. The requirement exists because earthing dramatically reduces the risk of fatal electrical accidents and is particularly important in damp areas such as bathrooms and kitchens where the risk of electrical accidents is higher.
How do you recognize if your outlet is grounded or ungrounded?
The easiest way to identify if your socket is earthed is to count the number of holes - earthed sockets always have three holes while unearthed ones have two. Earthed sockets usually have a round shape with three holes arranged in a triangle, or a rectangular shape with the holes in a row.
In older properties from the 1960s and earlier, most sockets are ungrounded, while sockets installed after the 1970s are more often grounded. You can also recognize earthed sockets by the fact that they are slightly deeper and have a more robust construction to accommodate the extra earthing wire.
Also check which plugs your appliances have. If you have appliances with three-pin plugs (three prongs) but can only connect them via adapters, your sockets are probably ungrounded. Modern sockets also often have a marking showing the earthing symbol - three horizontal lines of decreasing size.
In older properties, you may come across sockets that look earthed but where the earthing function is not working properly. If in doubt, have the sockets tested by a qualified electrician using appropriate measuring instruments.
Which appliances require earthed sockets for safe operation?
Any appliance with a metal casing and a higher power rating requires earthed sockets for safe use. This includes white goods such as refrigerators, washing machines, dishwashers and cookers, as well as computers, printers and other electronic equipment with metal parts that you can touch.
Electric tools such as drills, circular saws and grinders must always be connected to earthed sockets. These appliances often have powerful motors and exposed metal parts that make them extra dangerous in case of insulation failure. The same applies to gardening equipment such as electric lawnmowers and hedge trimmers.
Appliances in humid environments such as bathrooms and kitchens require specially earthed sockets. This includes hairdryers, kettles, microwave ovens and all appliances used near water. Moisture dramatically increases the risk of electric shock, making earthing particularly important.
If you use ungrounded sockets for appliances that require grounding, the safety protection disappears completely. The appliances may still work, but you run a high risk of electrocution if they fail. Never use adapters to connect three-pin plugs to ungrounded outlets - this eliminates grounding protection.
When should you upgrade from ungrounded to grounded outlets?
You should upgrade to earthed sockets when you use modern appliances with three-pin plugs, plan kitchen renovations or have sockets in damp areas. Upgrading is also necessary if you frequently use adapters to connect grounded appliances to ungrounded outlets.
From a safety point of view, upgrading is particularly important in bathrooms, kitchens and laundry rooms where the risk of electrical accidents is highest. If your house was built before 1970 and never had the electrical installation updated, you should consider upgrading the entire electrical system to meet modern safety standards.
The cost of upgrading individual sockets varies depending on how easy it is to run new wiring. If earthing wires are already present in the wall, the work is relatively easy and cheap. If there is no earthing wire at all, new cables have to be laid, which can be more expensive and require more extensive work.
Always contact a qualified electrician for socket upgrades. Electrical work requires special skills and incorrect installations can cause fires or electrical accidents. An electrician can also check that your entire electrical installation works safely and complies with current regulations.
How 24 Center helps with electrical installations and outlets
24 Center offers 24/7 professional electrician services for all types of electrical installations and outlets. Our skilled electricians handle everything from emergency electrical faults to planned outlet and security system upgrades.
Our services include:
- Upgrading from ungrounded to grounded sockets
- Installation of new electrical outlets and lighting
- Inspection and testing of earthing systems
- Emergency electricity service in case of power cuts and failures
- Installation of electrical locking and alarm systems
- Safety checks of electrical installations
With our local focus and extensive network, we are available throughout Sweden. Our technicians know the local building stock and can quickly assess which solutions are best for your property.
Call 08 40 24 240 for immediate help with electrical installations or book online for planned work. We offer both emergency service and scheduled visits depending on your needs.
Frequently asked questions
Can I replace ungrounded sockets with grounded sockets myself?
No, electrical work must be carried out by a qualified electrician according to Swedish law. Even if it seems simple to change the socket, knowledge of safety, wiring and testing the earthing function is required. Incorrect installations can cause fires or electrical accidents, so always contact a professional electrician.
What is the cost of upgrading all sockets in an older house?
The cost varies between SEK 1500-4000 per outlet, depending on whether the earthing cable is already in place or has to be re-laid. For a whole house, the total cost can be SEK 30 000-80 000. An electrician can do a free inspection and give you an exact quote based on your house's specific conditions.
Is it dangerous to use adapters to connect grounded appliances to ungrounded sockets?
Yes, it is very dangerous because the adapter eliminates the earthing protection completely. The appliance still works but you lose the safety protection against electric shock in case of failure. This is particularly risky for powerful appliances such as tools and white goods with metal casings.
How do I know if the earthing in my socket is actually working?
Even sockets with three holes can have defective earthing, especially in older houses. An electrician can test the earthing function with special instruments that measure resistance and continuity. Signs of problems may be that earth leakage circuit breakers do not trip when tested or that you get light shocks from appliances.
Which rooms in the home have the highest priority for earthed sockets?
Bathrooms, kitchens and laundry rooms are the highest priority because moisture dramatically increases the risk of electrocution. Next come living rooms and bedrooms where you use computers and electronics. Garages and hobby rooms where you use power tools are also important to prioritize for safety.
Can I get an electric shock from an ungrounded outlet even if the appliance is working normally?
Yes, if the insulation of the appliance deteriorates over time, metal parts can become live without the appliance stopping working. With an ungrounded outlet, there is no protection to dissipate the fault current, so you risk electrocution when you touch the appliance. Grounded outlets prevent this by immediately diverting the fault current.