Ambient Temperature (Ta) Derating Checker
Compare site temperature with the stated nameplate ambient range. Any over-temperature arithmetic is an illustrative sensitivity check, not a new certified T-class.
Screening only. This tool does not classify hazardous areas or approve a product, installation or safety system. Use the applicable project requirements, manufacturer data and exact certificate conditions.
Method & limits
Within the entered range, PASS means only that this ambient-range check passes. Above upper Ta, the tool adds the exceedance to the T-class ceiling as a hypothetical one-for-one temperature-rise illustration. It does not establish the actual surface temperature or extend certification. Below lower Ta, cold-performance and certification review are required; no T-class assurance is given.
Frequently asked questions
Does PASS approve a light?
No. It only compares the entered site temperature with the entered Ta bounds. Verify the exact model, loading, certificate and special conditions.
Is the estimated class certified?
No. The arithmetic assumes a one-for-one rise and is not a validated thermal model or a new equipment rating.
What if lower Ta is unknown?
Only the upper-bound check is available. The tool explicitly leaves low-temperature suitability unverified.
What does a cold-range warning mean?
The entered temperature is below the nameplate range. Materials, seals, starting and protection performance need manufacturer review.
Can I use this for area classification?
No. The site classification must come from the project assessment; this tool neither assigns a zone nor approves equipment.
Sources & verification
Source and calculation review: 2026-11-05. Reference methods do not replace the edition adopted for your project.