EUCHNER CTA-L1-BP-U-HA-AP-SA Guard Locking Safety Switch

Heavy-duty RFID guard locking in a die-cast zinc housing

The EUCHNER CTA-L1-BP-U-HA-AP-SA (order no. 166702) is a transponder-coded safety switch with guard locking from the EUCHNER CTA series. Its housing and head cover are die-cast zinc, it holds a guard closed with up to 8000 N, and it is sealed to IP65, IP67, IP69 and IP69K, which suits machines that are washed down or exposed to coolant and impact. It is a BP type: a single device for stand-alone wiring to a safety relay or safe PLC through one 8-pin M12 plug.

Guard locking follows the closed-circuit current principle (L1): a spring holds the bolt locked until 24 V is applied to the solenoid, so the guard stays locked during a power failure. Unicode evaluation means only the last taught-in actuator is accepted, giving high protection against defeat.

Technical specifications

Values from the EUCHNER product data for order no. 166702.

Wiring the M12 connector

Releases and installation notes

For faults or setup, the auxiliary release lets the guard be opened without power; the operating instructions require it to be sealed against tampering, and the safety outputs switch off while it is used. On CTA devices an escape release for people trapped inside the guard is optional or can be retrofitted with a blind flange. Separate supplies are used for the electronics and solenoid, protected externally (0.25 to 8 A and 0.5 to 8 A). Because the control of guard locking is handled outside the switch, its PL depends on the external circuit. Protect inductive loads on the outputs with a free-wheeling diode, and for UL use operate from a Class 2 supply.

Documents and quotation

The attached EUCHNER operating instructions cover the CTP and CTA L1/L2 BP versions, including status tables and connection examples. For a quotation, give the order number 166702 and the actuator type required. Other interlocks are listed under Safety Switches and Guard Locking.

How the EUCHNER CTA-L1-BP-U-HA-AP-SA works

The EUCHNER CTA is a transponder-coded safety switch with guard locking for movable safety guards. A coded actuator mounted on the door enters the switch head and is detected and locked by the switch; the machine control only releases hazardous motion when the guard is closed and locked. The variant described here uses guard locking with an escape release and auxiliary release functions as specified in the product code, with actuator ordered separately.

Key points of the EUCHNER CTA-L1-BP-U-HA-AP-SA

• Weight approximately 1.08 kg according to the EUCHNER product page.
• Actuating force 10 N, maximum approach speed 20 m/min and overtravel 5 mm.
• Ready delay of 5 s after power on.
• c-UL-us and FCC approvals listed by the manufacturer.
• Actuator ordered separately.

Selection & Ordering Guide

Choosing the right EUCHNER CTA-L1-BP-U-HA-AP-SA configuration

Confirm the coding level required by your risk assessment, the release functions needed (escape, emergency or auxiliary release), the actuator type and the connector. Check that the guard locking principle and the safety function suit the required performance level.

Our team can help confirm the correct ordering code and accessories against the manufacturer documentation before you place an order, so the delivered item matches your application.

Installation & Maintenance

Mount the switch and actuator on rigid parts of the guard, aligned within the tolerances in the operating instructions, and protect them from impact. Verify the safety function after installation and at regular intervals, and never bypass or defeat the switch.

Always follow the manufacturer instructions supplied with the product, use qualified personnel for installation and electrical work, and keep records of inspections and replacements so that maintenance can be planned rather than reactive.

Typical Applications in Oman & the GCC

In Oman and the GCC, the CTA suits safety guards on packaging lines, machine tools, robot cells and process machinery in manufacturing, food, oil and gas and utilities, where guards must stay locked until hazardous motion has stopped.

Practical Notes for Machine Safety Engineers

A safety switch with guard locking is only one part of a complete safety function. The control system, wiring, stopping time of the machine and the release procedure must all be considered together in the risk assessment and in the validation of the performance level. Plan where the escape release or other release functions will be operated, and make sure operators cannot be trapped inside a guarded area. Choose cable routing and mounting positions that avoid damage from forklifts, coolant or cleaning, and label the switches clearly so maintenance staff can identify them quickly. Keep the operating instructions and the declaration of conformity with the machine documentation, and include periodic functional tests of the switch and actuator in the planned maintenance schedule so faults are found before they become hazards.

Spare actuators and a replacement switch of the same order number reduce downtime when a guard is damaged, and keeping them in stock avoids temptation to bypass the safety device while waiting for parts.

Why Source from Seven Star LLC

Seven Star LLC supplies industrial equipment, spares and consumables to contractors, fabricators, plants and maintenance teams across Oman and the GCC. Send us the model, quantity and any project or plant requirements to request a quote, and our team will help you confirm the right specification for your application.