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Limit Switches Selection Guide

Mar. 13, 2024

TZ-3 series, is the name of our series of waterproof limit switches, these switches are usually used when the switches are required to work in wet environments, such as marine applications, outdoor equipment, or food and beverage processing. TMAZTZ waterproof limit switches are made of high-quality aluminium as the housing, and the bottom of it is sealed with resin, and rubber ring seals are used in the joints of each part to prevent water from entering the inside.

1) When you need to choose TZ-3 limit switch

First of all, we need to know that high IP rating switches include more flexible rubber rings, more precise moulds and more testing processes at later stages. This causes the cost of waterproof limit switches to be much higher than conventional products.

Some of the use of the environment itself is dry, it is not necessary to use a high IP grade switch; in other places, the travel switch will be installed in a switch box, which reduces the purchase cost, but also convenient to replace the installation, can be said to be two birds with one stone.  


In such cases, the scenarios for choosing TMAZTZ TZ-3 waterproof limit switches become: the use of a wet environment (or even immersed in water from time to time), or the limited space for action, which prevents the installation of a switch box. Or the switch needs to be moved in the process of use after the installation is completed, for fear of water leakage caused by poor wiring at a later stage, so it is directly chosen to be fixed with resin at the production stage.

 Limit Switch Selection Methods

2) How to choose the right operating mechanism?

The operating head of TMAZTZ limit switch can be roughly divided into plunger type, spring type and pendulum type.

 Limit Switch Selection Methods

If it is an old project, you can directly choose the previous operating head, and if it is a new project, we give the following reference:

TZ-31□1, TZ-31□2, TZ-31□3 series, suitable for the occasion of higher limit precision

TZ-3107, TZ-3104, TZ-3108, their pendulum position can be adjusted, which has high flexibility in installation

TZ-3166/67/68/69, the spring-type mechanism is suitable for detecting bumpers from all directions.


3) Matters to be noted for installation and use

In the installation process, in addition to the common TMAZTZ limit switches, set the angle of the bumpers <30 °, the use of moderate torque screwdriver. There are also some installation precautions that are unique to waterproof switches:

I) Before our switches are shipped out of the factory, we will carry out tests such as pulling out, twisting and bending of cables according to batches to ensure that the most critical resin part is frozen firmly. Users are advised not to pull out the cables by force during normal use, as this may cause a loss of protection. For example, if the cable is twisted at a large angle for a long period of time after wiring, or if a heavy object is hung on the cable.

(II) The wiring should be fixed 5cm away from the shut-off, and the bending radius of the wires should not be less than R45cm, and the insulation should not be hurt during installation to avoid leakage of the wires.

 Limit Switch Selection Methods

(III) For TZ-3104/07/08 switches, it is better not to actuate the switch more than 90° frequently, as this will make the life of the switch decrease rapidly.

IV) Since the TZ-3 waterproof switch is often used in humid environments, be sure to keep the earth wire connected (yellow/green cable).

 Limit Switch Selection Methods

Limit Switch Selection Methods


Thank you for reading!



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