Limit Switch on Control Cabinet

Case Study: Limit Switch on Control Cabinet

Location: Zhejiang Province, China

Product Used: TZ-8122 Limit Switch（https://www.chinalimitswitch.com/tz-8-limit-switch/tz-8122.html）

Case Images:

Selection Process

1）Project Background

In 2020, we were approached by a local control cabinet manufacturer to select a limit switch for their product.

In control cabinets, limit switches are typically integrated with the main circuit to achieve "cabinet door opening → equipment shutdown" for maintenance safety. While standard TM-1704 micro switches had sufficed in most past projects, this case presented unique requirements:

Harsh Environment:

The cabinets were installed in an aluminum die-casting workshop with heavy dust exposure. Despite cabinet enclosures, the client demanded IP-rated and shock-resistant switches.

Vibration Resistance:

Proximity to large machinery caused continuous vibrations during operation.

Climate Challenges:

High temperatures and humidity necessitated dustproof and stable contacts.

2）Selection Criteria

We identified the TZ-8 Series as the optimal solution due to:

✔ IP65 Protection (sealed rubber design at switch head/cover), exceeding cabinet requirements.

✔ Zinc Alloy Base + Reinforced Plastic Housing: Balanced impact resistance and cost efficiency.

✔ Silver-Alloy Contacts: Initial contact resistance ≤25mΩ for long-term signal stability.

Final Model: TZ-8122 Roller Plunger Switch

Two installation options were evaluated:

Plunger-Type Switches (e.g., TZ-8111/TZ-8112/TZ-8122) mounted directly opposite the cabinet door.

Lever-Type Switches (e.g., TZ-8104/TZ-8107/TZ-8108) installed on the cabinet side.

3）Why TZ-8122?

Cost-Effective: Lower price than lever-type alternatives.

Precision: Higher repeat accuracy under repeated door operations.

Durability: Roller design absorbs door impact and positional deviations.

4）Outcome

By analyzing environmental needs, comparing structural designs, and validating key parameters, the TZ-8122 roller plunger switch successfully met the client’s demands for safety, reliability, and cost-effectiveness in alu