A plastics manufacturer needed a safety interlock on a beside-press granulator. An economy-grade solution with engineering plastic housing met every mechanical and compliance requirement — at the right cost.
The Problem
A semi-exposed automated parking system on the coast of New York needed limit switches for travel detection on vehicle pallet carriers. The equipment operated outdoors, exposed to salty coastal humidity, seasonal rain, and temperature fluctuations between summer heat and winter freezes. The customer had previously used a generic switch from another supplier and experienced contact corrosion within six months of installation.
First Recommendation
We recommended the TZ-8108, our standard IP65 limit switch with zinc-alloy base and sealed head. The customer ordered samples and tested them on-site. Within weeks, the samples were returned — the IP65 rating was not sufficient for the combination of coastal humidity and open-air exposure. Water ingress at the conduit entry point had begun to affect contact resistance.
What We Learned
IP65 protects against low-pressure water jets from any direction. It does not protect against sustained humidity with salt content, which penetrates through micro-gaps over time. The conduit entry — where the cable enters the switch body — was the failure point. Epoxy sealing at this junction was the solution.
Final Solution
We compared the TZ-3108 and TZ-3169, both rated IP67, on three criteria: full epoxy-sealed cable entry, mounting hole compatibility with the existing installation, and unit cost. The TZ-3169 matched the customer’s mounting dimensions exactly — no re-drilling required — and its epoxy-sealed conduit entry eliminated the moisture path that had compromised the first sample. The customer tested the TZ-3169 through a full seasonal cycle. It passed. They standardised across all sites.
Outcome
The customer now uses the TZ-3169 exclusively across all automated parking installations. The initial failure led to a stronger specification — and a relationship based on the understanding that we ship first, listen carefully, and refine until the switch fits the environment, not the other way around.
