What Is a Pull Cord Switch? Its Working and Importance

Pull Cord Switch

A conveyor system is a quick and effective piece of equipment used in industrial settings to move various heavy loads and products throughout a space. The major purposes of this method are to lower hazards at work and save time, money, and labor. Different safety switches, such as electronic switches, pull cord switches, conveyor safety switches, electronic conveyor switches, etc., can regulate a conveyor system.

The red mushroom-head push button is, without a doubt. The most widely used emergency stop device, and they appear to be everywhere. The pull cord is the second most popular emergency stop mechanism, and like the light curtain in safety equipment. It’s likely the one that gets used incorrectly the most.

What exactly is a pull cord switch, and how does it work? Does it have any benefits for you? If you are looking for answers to these questions. This post has already done that for you and has discussed the pull cord switches in detail below. 

Pull Cord Switch- What Is It?

A pull cord switch is an emergency switch that may be useful for stopping the conveyor immediately in the event of an accident or any other dangerous situation. One may use the traction cable switch in any position since it is built in. Such a way as to position it on the side of the conveyor belt and ensure that the traction cable is along the conveyor.

A cable running down the conveyor is great for manually activating the pull cord switch positioned along the conveyor beam. You can pull the cable anywhere along the conveyor to stop it in an emergency. It is always advisable to install a pull cord switch with the help of a professional. As it can be complicated for someone who does not know much about the installation process.

Image Source

Construction

These switches are built to actuate instantly even if left unused for a long time since they are best as safety or emergency switches, which are not much utilized.

Pull cord switches remain protected by IP65-rated dust- and waterproof casing. A sturdy, heavy-duty cam switch with strong contacts is usually beneficial to provide prolonged service life. With spring steel rings for fastening the rope at both ends, it comes equipped with an operating handle. Maximum operational flexibility comes from the rings’ design. Epoxy paint is used on the enclosure to provide great corrosion resistance. The switch has a manual reset mechanism built into it.

The pull cord switch has the following main components:

  • Name Plate

The nameplate of this switch offers information about the rating, type, contacts, serial number, etc.

  • Cable Entry

An enclosure made of rubber covers the electrical cable’s entrance.

  • Operating Spindle

Steel rings on this spindle help secure the rope. As a result, the operator pulls on this rope to operate the switch.

  • Mounting Mechanism

The user can attach this switch by mounting bolts on the conveyor’s face.

  • Electrical Terminals

This switch’s electrical terminals have ordinarily open (NO) or normally closed (NC) contacts that function according to the logic used by the designer.

Image Source

Operation of Pull Cord Switch

On either side of the belt conveyor, you will find the pull cord switch positioned ideally at a distance of 20 to 25 meters. The switch gets activated when you manually pull the rope, and it stays in operation until you restore it manually to its default position. With a two-core cable, all the pull cord switches remain linked to the control station either in series or parallel, depending on the situation. Therefore, when any pull cord switch activates, the belt conveyor will halt until that specific switch is manually reset.

Applications of Pull Cord Switches

The following are some uses for pull cord switches.

  • These switches are conveyor safety devices that help link with conveyor shutdown systems in the event of emergency or maintenance. 
  • They are beneficial as a security switch to stop the conveyor belt in an emergency.
  • You can mostly find its application in the food, packaging, and beverage sectors and in the cement, coal, steel, and power plants where belt conveyor systems are primarily available.

Image Source

Importance of Emergency Stop Pull-Cord Switches 

Emergency cable pull switches help to offer continuous emergency stop control along exposed machinery. And conveyor systems that pose risks to users or maintenance employees. As a result, they can satisfy the requirement that every location where a job-related task is in the process must have a method of emergency shutdown. You can activate an emergency cable-pull system instead of remote E-Stop push buttons at any point along the ‘trip wire.’

Emergency stop pull wires are primarily beneficial in places with extensive equipment sections between regular operator stations. Pull-wire emergency stop mechanisms, for instance, are frequently employed on conveyors and other long equipment. Correct installation might be difficult since proper cable tension and support are crucial.

Keep in mind that emergency stop systems are additional safety precautions. The main protection devices remain backed up by complementary protective measures. Which do not offer protection to prevent someone from being entangled, hit, or dragged by any material stuck on its belt.

Conclusion

The process by which one activates the pull cord switches is the sole difference between them and ordinary switches in terms of how they function. These switches are mostly present in bathrooms and other damp areas. This post stresses that it is advisable to call a professional to work on anything like this because all the same safety regulations apply.