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Cable Structure

Common Types of Cord Reels Explained

By John Hamlin

Original article found at https://www.iqsdirectory.com/articles/hose-reel/cord-reels.html?msID=525d9c5f-9e0d-4e99-8e31-2b589a948e81

Introduction

This article takes an in-depth look at cord reels and their configurations.

Read further and learn more about topics such as:

  • What are Cord Reels
  • Types of Cord Reels
  • Cord Reel Configurations
  • Cord Reel Selection
  • And Much More…

Chapter 1: What are Cord Reels?

Cord reels are devices that hold extension cords that are used to supply power to electrical equipment or devices located far from the power outlet. They are also used in storing long extension cords properly.

How do Cord Reels Work?

Cord reels consist of a cylindrical reel drum that carries the wounded electrical cord within its capacity. The reel drum has two large flanges or discs on its ends to secure the cord on the drum. The reel drum is supported by the frame, which has the accessories (e.g., brackets, bases) to mount the cord reel in a particular location. They can be easily mounted on floors, ceilings, posts, walls, carts, and equipment.

The desired length of the cord is pulled out to make the necessary electrical connection. The cord in its extended position is called the payout position. The equipment plug is then inserted into the receptacles installed in the cord reel or at the end of the cable. The unused length of the cord is kept coiled on the reel drum. When power is no longer needed, the winding mechanism retracts and rewinds the cord onto the reel drum.

Benefits of a Cord Reel

Cord reels are used in many industries as they are beneficial in prolonging the service lives of power and extension cords. They prevent the cords from being tangled and nested. They protect them from wear, abrasion, and damage by only exposing the cord length necessary for electrical connection. Furthermore, cord reels are an essential safety accessory. They prevent accidents and damages due to tripping hazards caused by cluttered cables. Lastly, cord reels offer convenience when the proper type, specifications, and installation method are utilized for a given application. Hence, acquiring a cord reel is a practical move.

Cord Reel Construction

Cord reels are typically made of plastic (e.g., PVC, ABS), fiberglass, stainless steel, and aluminum. Metal cord reels are used for thicker and heavier cords. They usually come with anti-corrosion coatings to protect them from weathering and harsh environments. On the other hand, plastic cord reels are used for lighter cords and are typically found indoors. High-end cord reels may be constructed to be water-resistant, non-sparking, dust-proof, and shock and vibration-resistant, which allow them to withstand extreme environmental conditions.

Chapter 2: Types of Cord Reels

The types of cord reels are the following. A cord reel may fall into more than one category.

Hand-Winding Cord Reels

Hand-winding or manual cord reels are operated by a hand crank that rotates the reel drum to uncoil the electrical cord. The hand crank is turned in the opposite direction to rewind the cord back to the reel when not in use. Hand-winding cord reels are used with lightweight or short cables, wherein manual winding and uncoiling do not require much effort. They are portable, inexpensive, and usually found in indoor areas such as homes, offices, and stores.

Retractable Cord Reels

Retractable cord reels automatically pull the cord back to the reel drum, making them easier to operate than manual cord reels. They use a spring mechanism to provide the retraction force. As the cord is uncoiled and pulled out for use, tension builds up on the steel torsion spring. Once the electrical power is no longer needed, the stored energy in the torsion spring is released, retracting the cord back to the reel.

As the desired length is pulled, the cord passes through a clearance between two roller guides. This clearance directs the motion of the cord. The roller guides are made from smooth material to protect the cord from wear. A ratcheting mechanism locks the reel drum in various rotational positions to hold the cord's pulled length. A stopper, whose size is larger than the said clearance, is placed near the end of the cord to hold its free end when fully retracted. The guide arm adjusts the payout angle.

Retractable cord reels can be installed in a central location of an area to organize the workplace. They are usually mounted in ceilings, walls, and workbenches. Retractable cord reels are usually found in service garages, machine shops, and manufacturing facilities.

Motor-Driven Cord Reels

Motor-driven cord reels have a motor that helps in retracting the cord onto the reel drum. They are typically employed when a large amount of retraction force is needed. They operate at slow speeds and provide a steady tension to the cord, thus preventing the cord from overstretching and damage.

An electric, hydraulic, and pneumatic motor may operate motor-driven cord reels. Electric motors are driven by AC or DC power from a mains outlet or power supply. They are easy to operate, inexpensive, and efficient. Hydraulic and pneumatic motors use pressurized liquid and compressed air, respectively. These motors are suitable for places with entirely no access to a power source. They do not overheat when overloaded and are used in environments with a high risk of fires and explosions.

Motor-drive cord reels are typically used in heavy-duty applications in outdoor or remote environments, such as mines, tunnels, refineries, construction sites, and water treatment plants.

Medical Cord Reels

Medical cord reels are specially designed for healthcare facilities such as hospital wards, operating rooms, emergency rooms, medical laboratories, and radiology rooms. They are also used in mobile clinics and laboratories.

Medical cord reels prevent tripping hazards in these facilities and protect the medical equipment from power interruption and damage, which can have harmful consequences to the patient. They typically feature a spring-driven retraction mechanism. The cord and the reel components are enclosed in a durable casing. The components of a medical cord reel are made from durable materials that are easy to clean, waterproof, corrosion-resistant, and antimicrobial.

Lighted Cord Reels

Lighted cord reels have an attached lamp at the free end of the power cord. The light source may be an incandescent, fluorescent, or LED lamp. The cord is pulled at the desired length, and the lamp is hung on a ceiling or wall above the area being observed. The light from the lamp may be directed flexibly for optimal lighting.

Lighted cord reels are conveniently used outdoors and in remote places with no power source nearby. They can also be used indoors, such as service garages, to direct additional light to the observed area.

Commercial Cord Reels

Commercial cord reels are optimally designed for light-duty applications. They are used in environments where corrosion is unlikely to occur. They are usually made of non-metallic material or stainless steel and are portable. They are commonly found in classrooms, offices, retail stores, and others.

Hazardous Location Cord Reels

Hazardous location or explosion-proof cord reels are developed to eliminate the possibility of sparking, which can lead to fires and explosions. They utilize a spark-free ratchet and an explosion-proof slip ring housing. Thus, they are certified for use in places accessible by ignitable and explosive substances such as mining areas, grain storage and handling silos, and production plants producing fuels, fertilizers, paints, explosives, and others.

Stainless Steel Cord Reels

Stainless steel cord reels are commonly constructed from stainless steel grade 304. Stainless steel has excellent mechanical properties (e.g., high strength and toughness) and corrosion resistance. They are used in food, pharmaceutical, and medical industries in which sanitation and contamination prevention are of great importance. Other industries may also benefit from the mechanical properties of stainless steel cord reels.

Live Connection Cord Reels

Live connection cord reels allow an uninterrupted flow of electricity on the cord while a portion of their length is attached to the reel. These cord reels are fitted with connection hardware containing electrical sockets. The collector ring is a critical component for live connection cord reels; the smooth winding and unwinding of the cord with live current depend on this component. The collector ring transmits power and electrical signals to rotate the reel drum.

Cord Storage Reels

Cord storage reels pile and organizes extension cords during storage. They consist of a reel drum and a frame with the needed accessories for mounting, and the extension cord is bought or acquired separately. A hand crank manually operates most cord storage reels. They are used for protecting and maintaining extension cords used infrequently. However, they are intended for cord storage and should not be used while the cord carries electricity. The extension cord must be unloaded from the reel before connecting it to a power source.

Open Cord Reels

Open cord reels have no enclosure or casing, allowing access to their internal components. This type is common in light-duty applications and non-corrosive environments.


Chapter 3: Cord Reel Configurations

The common installation arrangements of cord reels depending on their usage are as follows. This aspect is an important consideration when selecting a cord reel.

Lift Configuration

In a lift configuration, a stationary cord reel is mounted at a wall or ceiling overhead the workstation. The electrical cord is vertically pulled down manually or by a machine. The cord reel is designed to carry and withstand the weight of the suspended cord and the outlet box at its end. Hence, the cord reel should be made from high-strength materials. A ratchet is used to lock the cord in place once it is extended. Lift-type is the most common configuration, usually found in manufacturing facilities and stores.

Drag Configuration

In a drag configuration, a stationary cord reel is mounted on a wall or column in a position slightly elevated from the ground. The cord is dragged from the reel horizontally by hand or equipment while it lies on the ground. A ratchet is used to lock the cord in place once it is extended. The cord may be moving and is extended flexibly to cover wider distances.

Stretch Configuration

In stretch configuration, the cord is stretched horizontally unsupported and extends with some sag. The cord reel may be stationary or moving and is installed elevated from the ground or on the ceiling. The cord must have 10% additional length as an allowance for the sag to cover the distance of the reel to the workstation.

Retrieve Configuration

In a retrieve configuration, the cord reel is mounted on moving equipment, and the free end of the cord is fixed on a supporting member. The cord unwinds and extends as the reel moves away from the supporting member. Conversely, the cord spools back as the cord reel approaches the supporting member. Strong spring tension is utilized to retract the cord with sufficient speed before the moving equipment overtakes the cable.

Vertical Pick-Up Configuration

In a vertical pick-up configuration, the cord reel is mounted on a machine member moving up and down. The power source is located at the end of the cord above the reel drum. The cord reel coils or unwinds as it moves together with the machine. Tight spring tension is necessary to feed the cord upward into the reel.

Chapter 4: Cord Reel Selection

The perfect cord reel may surprisingly increase productivity and safety in your workplace. However, there are many designs available in the market. The following are the considerations in selecting cord reels fit for a given application:

Type and Dimensions of the Cord

The cord that the reel will handle is the first thing to consider. The type and the dimensions of the cord, such as outer diameter, length, bend radius, and gauge number, must be gathered before purchasing a cord reel. The cord dimensions affect the sizing of the reel; longer and thicker cords require a larger cord reel. The weight of the cord should also be considered. The retraction of heavier and longer cords requires greater effort and may require an automatic retraction mechanism to save time and labor.

Required Cord Length

The required cord length must be estimated in order to select the live connection cord reel, which covers the distance between the power source and the workstation. The following are the operating parameters of cord reels pertaining to the required cord length:

  • Active length is the length available for extension in order to cover the distance from the cord reel to the workstation or area. It is the difference between the lengths during maximum and minimum payouts.
  • Inactive length is the length that stays outside of the reel even after full retraction. It is the length at the minimum payout.
  • Sag allowance is the length allotted for sagging. Sagging occurs as gravity pulls the weight of the cord if it is unsupported and horizontally stretched (stretch configuration). As a rule of thumb, at least ten percent of the active and inactive lengths must be added to the total cord length in order to accommodate sagging. This percentage is called the sag factor.
  • Lift height is the vertical distance of the reel drum to the location where the cord is laid down. This dimension is applicable for drag and retrieve configurations.
  • Hook-up length is the length required to make the connection at the free end of the cord.
  • Payout angle is the angular offset of the cord from the center of the reel in its extended position. If the payout angle is too large, the cord may experience tensile stress when it is in an extended position which damages and shortens the service life of the cord. A swivel base or a swing mount must be used if the payout angle is more than 150 to provide a wider range of motion to the cord.

Electrical Requirements

Live connection cord reels typically have a cord of a certain length and connection hardware upon acquisition. Hence, they must have the appropriate amperage, voltage rating, and plug and socket type in order to transmit electricity from the mains power supply to the equipment reliably.

The connection hardware must have a sufficient number of electrical outlets to accommodate the number of devices you have. There are many safety features available for this component. A socket with a grounding terminal may be selected for enhanced safety. A cord reel equipped with an automatic circuit breaker also protects you and your devices during short circuits and unusual peaks in current. Lastly, USB slots are available in some cord reels to accommodate USB charging.

Reel Working Environment

The working environment in which the cord reel is intended to operate must be considered. A good enclosure or casing protects the internal components of the cord reel from damage, moisture, corrosion, dust, and debris. The enclosure ensures optimal performance and reliability of cord reels in outdoor and harsh environments. Therefore, enclosed cord reels are more advantageous compared to open cord reels.

The standardized systems commonly used for rating cord reel enclosures are as follows. The manufacturer typically specifies the rating of cord reel enclosures used.

  • IP Rating System. IP (Ingress Protection) ratings are used to classify electrical enclosures based on their sealing effectiveness against unwanted intrusion of foreign bodies and moisture. They indicate the suitability of the device for use in a specific environment. IP ratings are assigned per EN 60529 or IEC 60509.

A two-digit code is assigned to each electrical enclosure. The first digit indicates the protection from foreign bodies and particulates. Meanwhile, the second digit indicates the protection from moisture and immersion in water. The digit is replaced by “X” if the enclosure is unrated or offers no protection.

  • NEMA Rating System NEMA ratings define the environmental conditions an electrical enclosure can withstand. They measure the enclosure’s capability of protecting the internal components of an electrical device from foreign materials, moisture, temperature, and corrosion. The National Electronic Manufacturer’s Association prescribes NEMA enclosure ratings.

UL Certification

Underwriters Laboratories (UL) is an independent organization based in Northbrook, Illinois. This organization consists of safety experts who test and evaluate various electrical products and components, including cord reels, for potential hazards.

The inspection, testing, and certification of cord reels are based on UL 355 or UL Standard for Safety Cord Reels. A UL certification attests that a cord reel is safe and functional based on rigorous quality and safety standards. A UL stamp may be seen on some cord reels to easily identify its certification.

Cord Reel Cost

Finally, the budget must be considered. Choose the cord reel with just the right features and specifications that perfectly fits your budget.

Conclusion

  • Cord reels are used in holding extension cords while supplying electricity to a device or equipment located far from the main power supply. They are also used in storing electrical cords.
  • Cord reels promote safety in the workplace and prolong the service life of electrical cords.
  • The types of cord reels are hand-winding cord reels, retractable cord reels, motor-driven cord reels, medical cord reels, lighted cord reels, commercial cord reels, hazardous location cord reels, stainless steel cord reels, live connection cord reels, cord storage reels, and open cord reels.
  • The common configurations of cord reels are lift, drag, stretch, retrieve, and pick-up.
  • When choosing a cord reel, the cord type, dimensions, required cord length, electrical requirements, environment, UL rating, and cost must be considered. The dimensions and weight of the cord primarily determine the appropriate retraction mechanism.
  • The operating parameters of cord reels pertaining to length are active length, inactive length, sag allowance, lift height, hook-up length, and payout angle.
  • The common rating system in classifying cord reel enclosures are the IP rating system and the NEMA rating system.

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