Guard Locking
Looking for more safety for your team?
Guard locking safety interlock switches from Bernstein ensure the safe operation of machine guards, doors and gates around high-risk industrial processes. These industrial guard locking devices secure access points until machines are fully stopped and safe to open. The SLC door interlock switch is modular and highly customisable.
Guard locking safety switches are machine safety devices that hold guards and access doors in a locked position until hazardous conditions are cleared. By combining guard monitoring and locking functions, these interlocks prevent premature access and ensure compliance with modern industrial safety standards such as ISO 14119 and ISO 13849-1.
Explore your options below.
It starts before the order
Three questions we ask alongside the part number, so the interlock holds the door the way the machine needs it held.
Where does it run?
The door, gate or guard it secures, how well aligned it is, the approach direction and hinge side, and whether anyone can be inside the danger area.
What is it doing?
Which locking principle the risk assessment calls for, how the door should behave on a power loss, and whether maintenance needs a manual release.
What if it is wrong?
A guard opened before the machine stopped, someone shut inside the danger area, an ISO 14119 audit finding, an actuator worn out by a misaligned door.
Customisable. Modular. Economical.
If you need to open a door while your machine is switched off, for maintenance work for example, the SLC has an Allen key-operated auxiliary manual release.
And with four slow-action contacts, you will always be able to tell:
Is the door closed or open? And locked or unlocked?
You can also choose from two different guard locking principles. This dictates behaviour during a power loss:
Spring-to-lock
Must be energised to unlock.
Power-to-lock
Must be de-energised to unlock.
What is guard locking?
Guard locking is a safety function that locks a safety guard in the closed position until all hazardous energy is neutralised, preventing machine restart and reducing risk of operator injury. Interlocks with guard locking combine monitoring and locking actions in one device.
Power-to-lock vs power-to-release
Many products support power-to-lock (PTL) or power-to-release (PTR) modes. Power-to-lock requires energising to unlock the guard, while power-to-release requires energising to lock, which affects behaviour during power loss.
Looking to replace or retrofit a door interlock switch?
Our technical team is here to help. Get in touch.
A truly modular switch
Five head positions. Four actuator options. Plenty of flexibility.
Set the SLC switch up your way.
The modular metal head can rotate 4×90°, or pop off the top cover and actuate from above. It is built to withstand high mechanical stress.
Choose from four different actuators, all high-quality stainless steel. Each actuator has a different minimum actuating radius.
Do not get stuck outside. Or caught inside.
Optional escape and emergency releases are available.
Set your team up with a clear path to safety, from either side of the door.
Escape release
Enables immediate opening from inside the dangerous area in case of an emergency. Sold as a basic set, with extension modules (20 and 40 mm) available.
Emergency release
For immediate opening from outside the dangerous area in case of an emergency.
Optional sliding handle actuator
Everything you need to get started.
The ergonomic handle guarantees that the actuator inserts correctly, every time, even for doors that are not perfectly aligned.
The variant with escape release (BF1-SLC ES) includes an additional handle to be able to open the door from within the danger area when using the function. This requires at least the basic set (ESCR-B).
Also available: SLK door interlock switch
Plastic-bodied, with guard locking, Bernstein's type SLK door interlock switch is still in use across Australia and the world.
The SLK switch is available in versions with spring force locking action and magnetic force locking action.
If you have got an SLK switch installed and you are looking for a like-for-like replacement, you can pick one up online today.
Shop OnlineOften scoped alongside
Ask us about guard locking interlocks for your access points
Send us the application: the door or gate, its alignment and approach, the locking principle your risk assessment calls for, how it should behave on a power loss, and whether you need escape or emergency releases. Our team will scope the switch, head, actuator and accessories to match.
We supply and support the product. Your team or your integrator installs and commissions it. We make sure it is the right one.