pylon with electric cables under a blue sky

RONIS Trapped Key Interlocking System

The safest way to work with high and medium voltage equipment

Contact us

How can companies protect their staffs?

In many industrial settings, a standardised procedure for operating, maintaining or accessing systems is necessary. One way to ensure correct and safe operation on a site is by using the RONIS trapped key interlocking system by DOM Security.

For more than 50 years, RONIS Trapped key interlocking system helps companies to regulate safe operation on-site. This system, in form of a series of keys, are intended to enforce the safety regulation in high and medium voltage installations. These regulations are made not only to protect the personnel while working in a high and medium voltage environment but also to protect the installation from any false maneuvres which could lead to damage.

These businesses trust us

Schneider Electric logo

VINCI Energies logo

ABB logo

"Thanks to years of partnership with DOM, we are always pleased about their daily support, providing reliable product and always keen to share their experience and develop new solutions."

Nick Cowen's photo, expert in occupational health and safety

Nick Cowen, Expert in Occupational Health and Safety

Different keys for different needs

You can choose the key type for your interlocking project: Standard Key or Reversible Key. Each with its' own strengths. Standard Key is made from brass, ensuring its' longevity, while Reversible Key guarantees more lock combination and higher security level.

Excellent after-sales service

Not only helping you with the project from the beginning, but the cooperation doesn't end during installation. Our after-sales team will always be ready to help you for any questions arise.

No limits & designed to last

RONIS Trapped Key Interlocking System is designed to last for generations to come. Our products offer no limits on combination or sequence.

RONIS Trapped Key Interlocking Systems catalogue


By clicking submit on this form, you acknowledge that the information you provide will be transferred to DOM Security for processing in accordance with our Data Protection Policy

Sequences of Trapped Key Interlocking System

Steps to protecting personnel and equipment

Step One: Isolating

Isolating is the first step of the trapped key interlocking system. Mechanical locks are used in this first step. In this important step, the power supply is switched off by turning the key from a latch bolt lock to the "power off" position. A system like this prevents staff from making accidental errors or taking unauthorised shortcuts around the established safe procedure. The same key will be used to execute the second step: exchange.

RONIS EL bolt lock
EL Bolt Lock


Step Two: Exchanging

The second step is in the trapped key interlocking system is called "Exchange". In this step, the key obtained from the first step (Isolate) is used to start a customised sequence of trapped and released keys. This step is used to open more devices, and sometimes this step may cover up to 24 cylinders, depending on the complexity of the system.

RONIS ELC exchange lock
ELC Exchange Lock


Step Three: Accessing

The last sequence of the trapped key interlocking systems is "Access". In this sequence, one key taken from the exchange box from the "Exchange" sequence, can be used to unlock access to electronic equipment.

RONIS ELP door lock
ELP Door Lock

Interlocking is for your business

We know your industry thanks to our experience. That’s why we develop the security solution that best suits your needs.

  • a young man holding a laptop verifies the functioning of the servers inside a rack cabinet protected by interlocking devices
    Areas and devices such as server and storage racks, mainframes, and network/telecommunication equipment may need interlocking products to secure the safety of the staffs and the devices.
  • two engineers check data on a tablet in a wind farm
    Energy sector such as wind, water or coal energy might use Trapped Key Interlocking System products to secure their machine sequence.
  • a hand operates with a wrench on an electrical panel protected by an interlocking system
    Trapped Key Interlocking System is used for switchgears in industrial or factory sites.
  • electronic equipment in a control room
    Energy plant can make use of trapped key interlocking system by RONIS in their control room.
  • two workers work on the switch track protected by an interlocking system
    Trains and railway sector also benefits from Trapped Key Interlocking System, especially for application in switch tracks, catenary protection, platform access, and signaling devices.

Contact us

Would you like to know more about RONIS trapped key interlocking system?
Fill in the form, our expert is ready to assist you and your projects.

By clicking submit on this form, you acknowledge that the information you provide will be transferred to DOM Security for processing in accordance with our Data Protection Policy