Do you require full power isolation for machinery access? Or do you want to avoid PLC’s and wiring, especially in a washdown environment? Perhaps you just can’t wire to that part of the machine easily.


Our Stainless Steel trapped key range is probably right for you – perfect washdown interlocks.

Stainless steel trapped key benefits

Stainless steel trapped key benefits

An example system:


  1. A Key operated switch (A) is being used to remove electrical power from a machine. The key is in the lock and cannot be removed until it is rotated, this, in turn, breaks the electrical contacts in the switch, turning off the machine. The electrical power for the machine and the key are linked, the machine can only have power while the key is in the key switch.
  2. The key is released and can be inserted into the key exchange (B) which contains three keys that are used to access the machine. These keys are trapped until the key from the key switch is inserted and turned, forcing a sequence.
  3. Once any of these “access keys” have been removed from the key exchange the key switch key is trapped in the key exchange and thus the power for the machine cannot be returned.
  4. The access keys are used to open access points using mechanical door modules (C). While the access points are open the keys are trapped in the locks, preventing the electrical power to the machine while an access point is open
  5. Some of these access points also contain “personnel keys” (D) which can be removed and taken inside a hazardous area during whole body access. This ensures the access keys are trapped, and the door remains open until the personnel key is returned, protecting the key carrier from an unexpected start-up of the machine





Washdown interlocks were never so easy!

Our Stainless Steel Trapped Key Products

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Want to build a complex stainless trapped key system or need something custom?

Machine Control

Our stainless steel, IP69, customisable control pods are pre-wired and tested, fitted with stainless steel QD connectors for quick installation.