KELLER Pressure 23SY-En Increased-Safety Pressure Transmitter
Manufacturer increased-safety pressure transmitter family. Specific Ex approval must be checked separately.
Original manufacturer: KELLER Pressure
Original Documentation
KELLER official model / family specification →
Exact measuring range, output and mechanical connections vary with ordering configuration. Do not treat model family as every orderable part number.
Ex / Hazardous-Area Document Check
Original-model Ex review (23SY-En): KELLER specifically describes the 23SY-En as intended for Zone 2 ATEX-required applications (increased-safety range). This does not establish suitability for Zone 1 or a flameproof Ex db rating. Verify the nameplate and valid conformity documents for the ordered version.
Original manufacturer product or certification documents →
Series 23SY-En — increased safety is not flameproof
Series 23SY-En belongs to KELLER’s increased-safety line and should not be substituted for the Ex db 33X-Ed merely because both refer to explosive atmospheres. Confirm the current manufacturer’s Ex ec marking, exact gas-zone allowance, wiring/accessory restrictions and certificate schedule. Select pressure port, output and wetted materials for the actual process. A claimed protection method requires the approved whole assembly; a photo and broad product family classification are insufficient.
Exact family and Ex safety check
KELLER announced an ATEX Zone 2 category 3G / Ex ec increased-safety series on 25 February 2026; Ex ec (Zone 2) is not Ex db flameproof, nor approval for Zones 0 or 1. Verify the exact unit label and conformity declaration.
Manufacturer’s Zone 2 ATEX announcement
KELLER’s 25 February 2026 manufacturer announcement identifies 23SY-En as a Zone 2, category 3G, Ex ec increased-safety option. This is not equivalent to Ex db (flameproof) or to an intrinsically safe Ex ia instrument. Verify the unit’s certified label, ambient limits and declared configuration before hazardous-area use.
23SY-En — increased safety for specified Zone 2 installations
| Selection item | Original manufacturer model-specific information |
|---|---|
| Pressure span | 0–0.1 through 0–1,000 bar depending on order code |
| Accuracy / total error | ±0.25% FS reference accuracy; ±0.7% FS TEB over −10…+80°C |
| Outputs | Analog 4–20 mA and 0–10 V choices |
| Protection technique | Manufacturer explicitly describes 23SY-En as increased-safety equipment for potentially explosive Zone 2 industrial applications; do not equate ‘En’ with an Ex d flameproof housing or the ‘Ei’ intrinsic-safety family |
| Engineering qualification | Require exact device label, protection marking, certificate annex, gas category, temperature class and permitted surrounding temperature, cable glands and installation instructions. ‘Zone 2 capable’ is not a blanket claim for all custom variants. |
What remains for final equipment approval
Match pressure range, relative/absolute reference, process port and materials, temperature range, wiring, operating limits and installed protective system. For hydrogen, distinguish material compatibility and leak-tightness from ignition/explosion protection. A family catalogue cannot substitute for a serial-specific applicable certificate schedule.
Primary manufacturer technical source: KELLER official 23SY-En Increased-Safety Pressure Transmitter model specifications.