KCD2-STC-Ex1 | HART-Transparent Isolated Barrier for 2-Wire Transmitters, 24V DC
KCD2-STC-Ex1 isolated barrier for 2-wire 4-20mA HART transmitters. Ex ia/IIC, 24V DC supply, HART passthrough, DIN rail mount, SIL 2/3.
Product Overview
The KCD2-STC-Ex1 (Order No. KCD2-STC-Ex1) is a single-channel isolated barrier from the K-System (KCD2) series, designed to power and isolate a 2-wire (loop-powered) 4-20mA HART transmitter installed in a hazardous area (Zone 0/1, Division 1). It provides intrinsic safety (Ex ia) energy limitation to the field side and a HART-transparent 4-20mA analog output to the safe-area control system. The device is SIL 2/3 capable and mounts on a standard 35mm DIN rail.
Technical Specifications (Electrical & Function)
| Parameter | Specification |
| Order Number | KCD2-STC-Ex1 |
| Function | Isolated Barrier for 2-Wire 4-20mA Transmitters (with HART Passthrough) |
| Supply Voltage (Terminals 7-8) | 20 … 30 V DC (Nominal 24 V DC) |
| Field-Side Output Voltage (Uo) | ≤ 28 V DC (Typical 24 V DC to power transmitter) |
| Field-Side Max. Current (Io) | ≤ 93 mA (sufficient for 2-wire Tx + HART) |
| Field-Side Max. Power (Po) | ≤ 0.65 W |
| Safe-Area Output | 4 … 20 mA (Active / Passive — mirrors field current) |
| HART Transparency | Yes — Full HART FSK Signal Passthrough (No HART filter / blocking) |
| Galvanic Isolation | 3 kV AC (Test) between Input/Output/Supply |
| Terminals | Screw Clamp (Cage Clamp) |
Technical Specifications (Mechanical & Certification)
| Parameter | Specification |
| Mounting | 35 mm DIN Rail (EN 60715, Top-hat) |
| Housing Width | 12.5 mm (K-System compact) |
| Connection Type | Screw Terminals (solid/stranded wire) |
| Operating Temperature | -20 … +60 °C |
| Storage Temperature | -40 … +85 °C |
| Protection Rating | IP20 (Enclosed in Cabinet) |
| Hazardous Area Approval | ATEX / IECEx: [Ex ia] IIC T4/T6
FM / cCSAus: Class I, Div. 1, Groups A-D |
| Functional Safety (SIL) | SIL 2 (SIL 3 via Architecture) per IEC 61508 / IEC 61511 |
| Standards | IEC 60079-0, IEC 60079-11, EN 50270 (EMC) |
Key Features
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HART Protocol Transparency: Passes HART FSK digital communication bidirectionally — enables remote configuration, trim, and diagnostics of smart transmitters without removing the barrier.
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Galvanic 3-Way Isolation: Separates hazardous area, safe area, and power supply — protects control system from ground loops and transient surges.
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Universal 2-Wire Transmitter Support: Powers any standard 4-20mA loop-powered HART transmitter (pressure, temperature, flow, level) in Ex ia circuits.
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Compact DIN Rail Footprint: 12.5 mm width — high-density marshalling in system cabinets.
Applications
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Hazardous Area Analog Loops: Connecting 4-20mA HART transmitters (e.g., Endress+Hauser, Yokogawa,) in Zone 1/Division 1 to DCS/PLC analog input cards.
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SIS & Process Control: SIL 2/3 capable — suitable for safety-related measurement loops where an isolated barrier is required.
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Fieldbus Migration: Retrofit legacy non-smart loops with HART-enabled transmitters — barrier remains in place without rewiring.
Note: For 2-channel version see KCD2-STC-Ex1.2 or KCD2-STC-Ex2 (dual channel). For non-HART / filtered version (blocks digital comms), see KCD2-SD-Ex1.xxx. Always verify Entity Parameters (Uo, Io, Po, Ci, Li) against your transmitter's Ex ia certification before installation.
About ACH
Founded in 2012, ACH is a top-tier distributor of industrial automation products, supplying genuine devices from leading brands like ABB, P+F, E&H, AB, MTL to emerging markets worldwide. Our mission is to provide 100% Genuine products at the most competitive prices, helping customers reduce costs and strengthen their market position.
Frequently Ask & Questions
Are preferential prices available?
Long-term brand partners can get competitive product prices. At the same time, ACH controls the profit per order to 5%, providing the most competitive prices.
Are the Products Genuine OEM Units?
Yes, all products from ACH are certified genuine OEM units. We acquire our inventory through official OEM channels and trusted third-party suppliers, ensuring every item is authentic and reliable.
How will you arrange shipment?
We'll handle the shipping for you. Through our partnerships, we can secure competitive rates with major carriers like FedEx, DHL, TNT, and UPS, ensuring a smooth and cost-effective delivery.
What is the warranty of goods?
One-year Warranty.
How long is the logistics cycle of the product?
Products are divided into spot and futures, and the delivery period of different brands of products is also different. For details, please contact the ACH business manager.
