DIY electrical extension cord: a step-by-step workshop

In everyday life, situations often arise when during construction work it is necessary to make a connection point on the building facade or to the fence. The stationary installation of the outlet, in this case, is both impractical and dangerous, so the power is supplied using an electric extension cord. In the same way, you can solve the design flaws of household appliances (short cord or section mismatch with load) or organize network connection points in any place convenient for you. To do this, you need to make an electric extension cord with your own hands.

What do you need to make an extension cord?

You can collect the electric carrier from any improvised materials (old household appliances, cable debris, etc.). If not, get all the items from scratch. For the manufacture, take the following materials and elements:

• collapsible plug;
• cable of the required length;
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• a closed electrical outlet or an outlet block (depending on how many connection points you need).

To disassemble the elements and then assemble an electric extension cord from them, use a screwdriver that is suitable in size and shape. To cut the wires you will need wire cutters or pliers, a stationery knife to remove insulation.

In order to prevent overheating and emergencies, all parts for electric carrying should be selected for specific needs.

How to choose materials?

All elements of the electric extension cord are selected according to the total power of the devices included in it. If you plan to install one outlet, take the power of the largest load that can be connected to it to calculate. In the case of simultaneous inclusion of several devices at several points at once, it is necessary to sum their power or amperage. Which selects the appropriate rating of the plug and socket, as well as cable cross section.

For example, if you install the unit on two sockets, one of which is designed for a vacuum cleaner consuming 5 A, and the second for an electric drill consuming 3 A. Thus, the total current is 8 A. Accordingly, in this case, plugs and sockets with a nominal value of 10 A are enough for you, while there remains a margin of 2 A if you need to connect a more powerful device.

To determine the cross-section of the wire, the same amount of load is used, to which 20 - 30% is added for the safety margin. The specific value of the core area is selected from the table so that the obtained value of the connected load does not exceed the allowable for this wire.

Table: load capacity versus core

For example, for a load of 8 A, you add 20% of the supply I = 8 + 1.6 = 9.6 A. Since a copper wire is much more convenient and preferable for an electric extension cord, consider it as an example. For this example, any brand of cable with a cross section of 1.5 mm is quite enough for you².

It should be noted if you intend to use a homemade extension cord in a three-wire system (phase, zero and ground), then you need a cable with three cores, and the sockets and switch must have three output. If only two wires are used in your house - phase and zero, it makes no sense to make an extension cord with three leads.

Extension cable manufacturing: step-by-step instructions

As a rule, the manufacturing process does not take much time, so if you have all the necessary elements and tools, you can make an electric extension cord in 15 to 20 minutes. To do this, follow these steps:

1. Disassemble the plug, as a rule, it is untwisted with one or several bolts, but the design may differ in different models.

   

2. Cut the electric cable, for this, back off the desired length from the point of its connection to the plug contacts to the place where the extension cord exits the plug. It should be noted that at the exit point the cable must have both layers of insulation, so do not strip the upper dielectric layer with a margin.

   

3. Prepare the wire to connect to the terminals of the plug. To do this, back off about 1 - 2 cm from the edge of each core and carefully cut the rubber insulation.

   

Be careful not to cut the wire core, otherwise it will reduce the cross-section and may lead to further overheating at the attachment point.

1. Depending on the mounting method in the plug contacts, prepare the ends of the wire (make loops, twist into one core, etc.).
2. Follow all these procedures for the other end of the wire.
3. Connect the ends of the wire to the ends of the plug and assemble it.

   

Note that the assembled fork should not have gaps - both parts fit snugly together. If you find a gap, disassemble it again and eliminate the cause of the unevenness. At the exit from the plug, the extension cord should be snug against the edges, if its diameter is not enough, add a little insulating tape.

1. Disassemble the electrical outlet or outlet unit, depending on what you are connecting.

   

As a standard, they are equipped with one bolt in the center of the socket, but if the cover does not lend itself, you should inspect the structure for any additional attachment points.

1. Connect the ends of the wire to the corresponding terminals of the electrical extension cord outlet.

   

If you are making a device for a three-wire network, be sure to follow the wire marking. Especially for a grounding wire, otherwise you can apply voltage to the device body.

1. Assemble the outlet in the reverse order; the electrical extension cord is ready.

Please note that when connecting certain parts, the contact must be provided using special clamps, sleeves or by soldering. In no case is it allowed to provide contact only by screwing the wire to the lamellas or other parts. After making the electrical extension cord, do not rush to plug it into a power outlet; first check if it is working properly using multimeter.

Checking the health of the electrical extension cord.

To check the carrying capacity, you need a regular multimeter or megaohmmeter. The whole process can be divided into a line integrity check and an isolation test. Initially set the multimeter to ringing:

• Plug one lead of the multimeter into the socket of the outlet, and with the second touch the contact of the plug of the electrical extension cord. If the device does not indicate the presence of a circuit, touch the second pin of the plug.
• Hold the multimeter probe on the same pin of the plug where the device showed the circuit and check the other sockets in the unit. Their contacts of the same name should also give a circuit on the bell of an electric extension cord.
• Check the second pair of pins of the electrical outlets and the extension plug; they should also indicate the presence of a chain on the bell.
• If you are using a three-wire extension cord, ring the circuit between the grounding contacts on the plug and each of the outlets in the same way.

The presence of a circuit between all of the listed terminals indicates that the extension cord can normally transmit electricity in a closed loop. But, in addition to the circuit, it is necessary to verify the insulation state. What is the megaohmmeter used for, but in its absence, you can use the same multimeter in the insulation measurement mode. For industrial purposes, measuring the insulation with a multimeter is not permissible, but for domestic needs this will be quite enough.

During the measurement process, you need to set a limit on the maximum resistance value, ohms or megohms. Bring the probes to the terminals of the phase and zero on the plug, if the resistance is more than 500 MΩ or infinity, its level is sufficient for the normal operation of the electric extension cord.

If the resistance tends to zero or is tens of Ohms, you have broken the insulation somewhere and you need to double-check all the places of electrical contacts in the extension cord. If there is a grounding contact, the resistance value must be checked even between the phase - ground and between zero - ground.

If in the manufactured electric extension cord during the tests you determined the integrity of the phase, zero and ground circuits, as well as a sufficient level of resistance between all the terminals, then such a carrying can be safely used to connect equipment.

Video instruction