Kobold KAL-D5408MST3 – KAL-D Compact Thermal Flow Switch, 1/4″ NPT, NPN NC, Micro-DC Plug
The Kobold KAL-D5408MST3 is a compact thermal (calorimetric) flow switch from Kobold’s KAL-D series. It has a 1/4″ NPT process connection, 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, which gives the control system a clear alarm signal. 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-D5408MST3
- Series: Kobold KAL-D compact thermal flow switch
- Measuring principle: Calorimetric, no moving parts
- Process connection: 1/4″ NPT
- 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-D5408MST3: NPN normally closed (this item)
- KAL-D5408NST3: NPN normally open
- KAL-D5408PST3: PNP normally open
- KAL-D5408RST3: PNP normally closed
Other connections: KAL-D5415 (1/2″ NPT), KAL-D1408 (1/4″ BSP), KAL-D1415 (1/2″ BSP) and KAL-D0412 (M12 × 1). A mating 807.037 plug with 6 ft cable is available as an accessory. The output type and contact function must match the control circuit. Our sales team can help you confirm the right version.
Typical Applications
- Low-flow alarms in cooling water circuits
- Protection of pumps against dry running
- Water treatment and dosing systems
- Replacement switches for installed KAL-D systems
Buy Kobold KAL-D5408MST3 from Atlantech Drives
- Fast sourcing, shipped worldwide
- 12-month warranty
- Senior commercial advice on flow switch versions and lead time
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