For power supply isolation types, separate the stated insulation classification from a withstand-voltage number. Functional, basic and reinforced describe different intended insulation roles; a pairwise hipot entry does not by itself classify the entire supply or certify the finished machine. Procurement should ask for explicit, revision-bound evidence rather than infer a safety claim from a large voltage value.
Three terms that should not be used interchangeably
Functional insulation concerns correct circuit operation, not an established shock-protection claim. Basic insulation denotes the first level of shock protection. A reinforced claim concerns one insulation system intended to provide the protection associated with double insulation under the applicable standard’s conditions. Texas Instruments’ isolation terminology explains these distinctions; it does not classify the WEHO unit pictured here.
Supplementary insulation is a further, independent layer associated with basic insulation. Keep it distinct from the three headline categories rather than using “reinforced” as a loose adjective for any design that seems robust. The required classification for actual equipment must come from its applicable safety assessment and verified component evidence.
Read every barrier pair in the table
The approved WEHO S-60 sheet names input-to-output, input-to-frame-ground and output-to-frame-ground test pairs. It lists 1.5kV for the first two and 0.5kV for the third, for one minute. These are different named relationships; one number cannot be moved to another pair or silently converted into a basic/reinforced classification.
The cited sheet does not provide an adopted certificate that identifies the S-60-24 as reinforced insulation. This article therefore makes no such claim. Similarly, a visible CE mark is part of the photographed product’s real markings—not a substitute for the exact evidence requested for the ordered variant and final application.
A procurement request with clear boundaries
Give the supplier the required full model, output variant and intended equipment context. Ask them to identify the applicable document revision, each barrier covered by the proposed classification, the test conditions and the supporting report or certificate. A family brochure, a photograph and a generic explanation of isolation may each be useful, but they do not replace one another.
| Ask for | Avoid accepting instead |
|---|---|
| Explicit insulation classification for the exact barrier and variant | “High isolation” without a defined claim. |
| Applicable document and report revision | A similar model’s certificate or another voltage variant. |
| Named barrier pair and test conditions | A voltage number without endpoints or duration. |
| Equipment-level safety assessment | An illustration that appears neatly wired. |
| Source identity and delivered-unit markings | A rewritten label that matches a preferred specification. |
Do not perform an improvised hipot test on installed equipment using this guide. High-voltage testing, protective-earth assessment and return-to-service decisions require qualified personnel, the applicable test plan and appropriate equipment. The article supplies a purchasing-document checklist, not a hazardous test instruction.
The real S-60-24 identity remains separate
The authentic source unit’s right-side label identifies S-60-24 and +24V2.5A. Its input marking is 100–120VAC1.4A /200–240VAC0.7A,50/60Hz. The family sheet uses different switched input-range wording. Preserve the physical label literally and ask which specification revision applies to the delivered order; do not blend the sources or invent a selector in an unseen face.
The chassis is 159 mm along the terminal-to-rear axis, 98 mm across the front and 38 mm from base to roof. The full mechanical drawing shows bottom and side threaded mounting features. The roof has real round perforations, the source yellow input-selector instruction sticker, and the exact photographed internal component pattern. It is neither a honeycomb-roof substitute nor a DIN-rail supply.
Why source-faithful application scenes matter
A real model can look correct while being shown with the wrong mount or terminal entry. The S-60-24 has five guarded front terminal positions ordered L, N, earth, −V, +V, with separate front adjustment and indicator components. Control wiring should not be invented through ventilation holes, and an extra terminal block cannot be added merely to simplify an illustration.
Keeping those details intact prevents an attractive picture from becoming false installation guidance. It still does not prove a finished machine’s safety. The illustrations are source-referenced application concepts, not photographs of customer installations or evidence of passed electrical tests.
Frequently asked questions
Does 1.5kV mean reinforced insulation?
No such conclusion is supported by this table alone. The named barrier, applicable classification and supporting revision-bound evidence must be explicit.
Is functional insulation the same as “non-isolated”?
Do not merge the terms. Functional insulation describes a role in the insulation terminology; whether a circuit has galvanic separation is a different question. Use the supplier’s documented architecture and classification.
Can the input-output value replace the output-ground value?
No. They identify different pairs in the actual source table. Keep the endpoints with each number.
What if the documentation does not state the required class?
Record the gap and request exact evidence or choose a candidate with the needed documented qualification. Do not infer a class from an image, CE marking or family name.
Sources and qualification boundary
WEHO S-60 English product page, reviewed 8 October 2026; approved enterprise-drive S-60/1.jpg and actual multi-view evidence; complete S-60 specification/drawing. Terminology: Texas Instruments, Understanding Functional Isolation. No WEHO insulation-class certification or finished-equipment compliance is asserted.
