Kobold KAL-D0412MST3 – KAL-D Compact Thermal Flow Switch, M12 × 1 Thread, NPN NC, Micro-DC Plug
The Kobold KAL-D0412MST3 is a compact thermal (calorimetric) flow switch from Kobold’s KAL-D series. It has an M12 × 1 metric process thread, an NPN normally closed transistor output, a 24 V DC supply and a 4-pin Micro-DC plug. Its wetted parts are 316L stainless steel.
The normally closed output is often preferred for monitoring and alarm circuits, because the output goes to its open (alarm) state not only when flow is lost but also if the switch loses power. The M12 × 1 thread is the most compact connection in the KAL-D range, suited to small pipes, manifolds and metric fittings. The KAL-D has no moving parts: its sensor tip is heated a few degrees above the liquid temperature, and the flowing liquid cools it in proportion to the flow velocity. When the flow reaches the field-adjustable setpoint, the output switches. A microcontroller compensates for changes in liquid temperature, and an 8-LED bargraph shows the flow trend and the setpoint.
Key Technical Data – Kobold KAL-D0412MST3
- Series: Kobold KAL-D compact thermal flow switch
- Measuring principle: Calorimetric, no moving parts
- Process connection: M12 × 1
- Media: Water-based liquids (at least 90 % water); not suitable for oils or fuels
- Switching range: 0.15–6.6 ft/s (approx. 0.05–2 m/s)
- Repeatability: ±2 %
- Response time: 5.6–12 s typical
- Max. pressure: 580 psig (40 bar)
- Operating temperature: –4 to +176 °F (–20 to +80 °C)
- Wetted parts: 316L stainless steel; housing 304 stainless steel
- Power supply: 24 V DC ±10 %, max. 150 mA
- Output: NPN open collector, normally closed, max. 400 mA, short-circuit protected
- Setpoint adjustment: Potentiometer, flashing LED on 8-LED bargraph
- Status indicator: Dual-colour LED (red = alarm, green = flow)
- Electrical connection: Micro-DC plug, 4-pin male
- Degree of protection: NEMA 4X / IP65
Choosing the Right KAL-D Version
- KAL-D0412MST3: M12 × 1, NPN normally closed (this item)
- KAL-D0412NST3: M12 × 1, NPN normally open
- KAL-D0412PST3 / RST3: PNP NO and PNP NC versions
- KAL-D5408MST3 / KAL-D5415MST3: 1/4″ and 1/2″ NPT versions
- KAL-D1408 / KAL-D1415: 1/4″ and 1/2″ BSP versions
A mating 807.037 plug with 6 ft cable is available as an accessory. Connection thread, output type and contact function must match the installation. Our sales team can help you confirm the right version.
Typical Applications
- Low-flow alarms in compact cooling circuits and manifolds
- Protection of pumps against dry running
- Water treatment and dosing systems
- Replacement switches for installed KAL-D systems
Buy Kobold KAL-D0412MST3 from Atlantech Drives
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- 12-month warranty
- Senior commercial advice on flow switch versions and lead time
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