Custom extension cords: What is the need for customizing your cables?

About Custom extension cords, An extension cord is used when the wires are shorter than the system needs.

Now, if you choose the wrong size of extension wire, it d you to join many of them, or maybe the extra length wastes. Also, it can be a dangerous move as well. 

It’s better to design and make custom extension cords for your application, protecting you from hazardous situations and improving quality. Let’s look into it further.

What are extension cords?

An extension or power cord consists of a switch at one end and a socket panel at the other.

Usually, the extension cord refers to the main household extension, but now it also refers to different types of attachments.

Extension cables usually have one type of switch and socket, but when they are different, these wires are “Adapter cords.”

These cables are around 2 to 30 feet and may extend up to 300 feet in length. They come in various colors, thicknesses, duties, and sizes.

For instance, the wires used in outdoor systems must endure moisture, cuts, UV radiation, etc.

That requires thick insulation and heavy shielding material.

Furthermore, the cord inside the electromagnetic fields needs a mechanism to cancel such noise.

Extension cords include additional safety features like grounding terminals, a fuse, a “power-on” indicator using a bulb, and a residual-current system.

Different Standards of extension cords 

Here are some standards the industry follows during the production of extension wires.

International Standards IEC 60320

IEC 60320 defines the extension cord standards for applications requiring up to 250 V.

Countries have different power wiring types, but it is the common international standard.

The C in IEC is the code used while manufacturing sockets and plugs. These areas’ voltage, current, and temperature requirements influence each plug design.

This IEC standard specifies the plug with an even number and the mating counterpart as an odd number.

Also, the corresponding male inlet is one number higher than its female outlet.

Thus, the popular combinations you can see are the C14 to C13 and C20 to C19.

Moreover, the power cord system also includes the C14 to C15 and C20 to C15.

The connector types C13, C15, and C19 are what you will commonly observe in the data centers.  

NEMA 5-15P (Type B)

Besides IEC, the countries have standards designed for that land area. NEMA is the standard adopted in Northern America and a few other countries.

It uses three-wire circuitry, including hot, neutral, and ground, while the ratings are 15A for current and 250V for voltage.

Usually, you will find the NEMA 5-15P plugs and 5-15R receptacles used with each other. However, the NEMA 5-15P combination with the C13 and C15 is popular.

CEE 7/7 (Type E, Type F)

In Europe, many countries follow the CEE 7/7 plugging standard, while some use CENELEC.

However, some states like Denmark, Malta, Ireland, Italy, Cyprus, Switzerland, and Gibraltar do not use this standard.

Other Standards: JIS C 8303, AS/NZS 3112, etc.

Countries like Argentina, South Korea, etc., also offer their plugging standard.

For instance, Brazil uses NBR 14146 standard, while Australia uses AS/NZS 3112 (Type 1), Japan uses JIS C 8303 (Type A, B), and so on.

However, these all might be variations of the IEC 60320 connector standard.

Different switches with single extensions.

Different switches with single extensions.

How to Make Your Standard Extension Cord

To make your extension cable, you can follow these simple steps.

Step 1

First, determine the length of the wire you need for the appliance.

If you are at the physical location, measure the distance and add three to four feet for safety concerns. But remember, the cord should be at most 24 feet.

Step 2

Go to your nearby hardware shop and get one 10/3 SJ cord and two plug caps. This 10/3 cord is a thick wire comprising green, white, and black wires.

Step 3

Take one point of the SJ cord and cut the insulation to expose the internal wires about an inch and a half so that you can link the connectors.

Step 4

Cut off the excess outer insulation and the thin cover on the internal wires. Do it carefully so that these thin wires are not damaged.

Step 5

Now, take the female plug cap, and with your screwdriver, lose the screws while holding it closed.

Then, open the plug cap and reveal the wiring terminals that are green, silver, and copper. Loose the screws on these terminals as well.

Step 6

Using the wire strippers, strip the insulation off the internal wires of the SJ cord.

Step 7

For the green terminal, choose the green wire of the cord while twisting the copper strands so they do not stand out.

Slip it inside the green terminal and then tighten the screw on it. Repeat the same process for white and black wires while slipping them into the silver and copper terminals.

Step 8

Recheck the terminals and wire strands for any loose connections. If there is any strand poking out of the link, re-fix the terminals.

Once sure, reclose the female plug and set the black sheath again while fitting the cord cap.

Step 9

Fix the male plug cap on the other end of the 10/3 SJ cord while repeating the steps from 3 to 8.

After finishing, plug the male switch into the socket, power it on, and check the voltage on the female end using a voltage tester.

It should be 120V; if not, recheck the connection on both sides.

Single-type plug extension

Single-type plug extension

Custom extension cords At Cloom

Custom power extensions can be a great source of efficient power supply if made correctly; when professionals get involved, things get even better.

At Cloom, we offer the following custom extension cords to get your hands over them.

Custom Power Cords (NEMA and IEC 60320)

NEMA and IEC power cords come with hand termination of IEC 60320 ends or straight blade/locking systems.

These cables comply with the 817 UL standard; you can buy them in extension or adapter cord form.

Cloom chooses premium flextime wires inside and outside the house and Cooper, Eaton, or Hubbel components.

Custom Molded Power Cords

Regarding molding IEC and NEMA electrical cables, Cloom has unmatched capabilities.

Since we have dozens of injection molding machines operating in our Asian plants and the necessary UL certifications, we can make quick-turn molded custom wires in the US and send them to you in less than seven business days.

Custom Pendant Power Cable

At Cloom, we make pendant extension cables with a blade or lock receptacle and plug. The boxes we feature with it are a standard metallic or yellow rubber coating.

With it is the SOOW or SJOOW cords that are heavy-duty and can be built to your requirements.

Custom Splitter Power Cords

Cloom can create various splitter power cables to suit almost any purpose.

We can develop a split cord solution for you if you are searching for three-phase to single-phase splitter cords due to a change in your data center or the limited availability of outlets on your server rack.

Custom IEC 60309 Power Cords

Cloom offers custom IE 60309 or IEC 309 extensions with IP44 and IP67 certified pin and sleeve devices from Mennekes, Hubbell, Cooper, and PCE.

Also, you can get our 309 pin/sleeve power cords as extension cables, plug adapters, and splitters.

Custom Ceiling Drop Power Cables

Ceiling drop cables have NEMA blades and lock-style plugs and are available in various customization, so you get it made according to your needs.

Additionally, we can create it with side cables to any outer jacket and inner conductor you select, with wire mesh grips, grounding on outlets, and standard or waterproof boxes.

Custom OEM / Hardwire Power Cords

Cloom is a market leader in the production of cables for OEMs and other wiring-related devices.

Our UL approved hardwire OEM extension cables have mechanical plugs that we mold or manually terminate.

With that, you can order any suitable electric wire that you need. 

These cables can be constructed with blunt cut or custom ROJ stripped ends and various crimp alternatives such as ground lugs, spade terminals, and quick disconnects.

For our OEM cables, we use ultrasonic welding to ensure that your connections remain durable for a longer time.

Custom Watertight / Marine Power Cords

Watertight, Marine supported extension cables are also available at Cloom that use Hubbel’s twist-lock plugs along with branded wet guard ends.

Also, if the application is up to 300V, we use SJOOW, and for higher than 600V, we use SOOW cables.

With TF Flextreme bulk cables, the waterproof quality of our wires doubles, making them reliable for heavy-duty uses.

Thus, it will be an excellent choice for watertight custom cable assemblies.

Custom extension cords with multiple outlets.

Extension cords with multiple outlets come in handy when you need to connect more than one appliance simultaneously.

Cloom offers a vast collection of multi-outlet extensions for different applications and users.

Also, you can call us to make your cord if you have any specific needs, although you may find one from our variety that fits your need.


Custom extension cords help you fix the wires perfectly to an application.

Hence, specify your needs to an expert and let them do the work for you with their specialized machinery and techniques.

Cloom comes with multiple wiring solutions so that you get what you want. 

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