Key Technical Specifications
- Product Model: CS4HA
- Manufacturer: KOGANEI (Japan)
- Switch Type: Reed Switch
- Operating Voltage: 5-24V DC
- Load Current: Max 40mA
- Indicator: Red LED (Operation Status)
- Wiring: 2-Wire (Non-polarity)
- Protection: IP67 (Connector Type)
- Operating Temp: -5°C to 60°C
- Mounting: Direct Mount / Band Mount
- Cable Length: Standard 0.5m (Check suffix)
Product Introduction
Pneumatic cylinders don’t care about your HMI graphics; they care about whether the piston actually hit the end stop. The KOGANEI CS4HA is the workhorse reed switch I’ve trusted on TDA and JDAS series cylinders for years. It’s a simple, non-polarized 2-wire sensor that snaps right onto the cylinder groove. No fancy IO-Link, no configuration software. Just a clean “make” or “break” signal when the magnet passes.Engineers stick with the CS4HA because it survives where solid-state sensors fail. The reed contact handles inductive kickback from solenoids better than most transistor outputs in this price class. I’ve seen these run for 5 million cycles on a stamping press without a single false trigger. Just remember: this specific revision is sensitive to strong external magnetic fields. Keep it away from your VFD cables or you’ll get ghost signals. Otherwise, it’s bulletproof.
Quality SOP & Tech Pitfalls
The Lab Report:
I don’t trust “tested” stickers. Every CS4HA gets a real workout before it ships.
- Visual Counterfeit Check: Inspect the KOGANEI logo depth and wire insulation quality. Fakes use brittle PVC that cracks when you bend it.
- Live Bench Test: Mounted on a JDAS16-10 test cylinder. We cycle the piston 50 times to verify LED response and contact bounce.
- Electrical Validation: Fluke 115 check for voltage drop across contacts. Must be <0.5V at 20mA load.
- Insulation Test: Megger test between wires and ground to ensure no moisture ingress.
- Packaging: Anti-static bag with desiccant. Reed switches hate humidity.
The Engineer’s Warning:
Don’t mix up CS4HA with CS4MA. They look identical, but the CS4HA is designed for the T-groove on older KOGANEI cylinders, while the CS4MA often fits the C-groove or different pitch. I once swapped them on a Friday night shutdown; the switch sat 2mm above the magnet and never triggered. We lost 4 hours chasing a “bad cylinder” that was actually just a wrong sensor footprint. Also, never cut the wires while powered. The inductive spike will weld the reed contacts shut instantly.
Installation & Configuration Guide
- Pre-Installation: ⚠️ KILL THE AIR. Bleed the line. Wait 30 seconds for the cylinder to depressurize. Take a photo of the old switch orientation.
- Removal: Loosen the band screw or slide the clip. Label the wires NOW. Brown is usually +, Blue is -, but on non-polarized reed switches, it doesn’t matter electrically. It matters for your next guy.
- Installation: Slide the CS4HA into the groove. Align it with the magnet position mark on the cylinder barrel. This prevents 90% of “sensor not working” calls. Tighten just enough to hold; overtightening cracks the plastic housing.
- Power-On & Testing: Apply 24V DC. Manually stroke the cylinder. Watch the red LED. It should snap on/off instantly. If it flickers, your magnet is weak or the switch is misaligned. Check your PLC input card for a solid green light.
Compatible Replacement Models
| Model | Compatibility Tier | Notes |
|---|---|---|
| CS4HA | ✅ Drop-in Replacement | Original spec. Non-polarized reed. |
| CS4MA | ⚠️ Check Groove Type | Same electricals, different mechanical mount. Verify T-slot vs C-slot. |
| CS3HA | ⚠️ Smaller Body | Fits tighter spaces, but verify magnet strength compatibility. |
| ZE102A | ❌ Solid State Upgrade | Requires polarity check. Better noise immunity, but more expensive. |
Frequently Asked Questions
Can I hot-swap this switch while the air is on?
Technically yes, electrically no. The CS4HA is 2-wire non-polarized, so you won’t blow it up by plugging it in live. But if the cylinder moves while your fingers are in the groove, you lose a digit. Always isolate energy.Why does my LED stay on constantly?
Two reasons. Either the switch is stuck too close to the magnet (move it back), or the reed contacts welded shut from switching an inductive load without a snubber. If moving it doesn’t fix it, trash it. Don’t try to tap it with a screwdriver; that’s a temporary fix that fails in 10 minutes.Is CS4HA the same as CS4HB?
No. The “B” suffix usually indicates a different lead length or connector type (like M8 plug vs pigtail). Electrically they are identical, but mechanically they might not fit your cable gland or conduit. Check the suffix.My PLC sees the signal, but the cylinder doesn’t move.
That’s not a sensor problem; that’s a logic or valve problem. The CS4HA is doing its job. Check your interlock conditions in the ladder logic. I’ve wasted hours replacing perfect sensors because someone forgot to reset a safety relay.How do I know if the magnet is dead?
Take a known good CS4HA and slide it over the cylinder while powered. If the LED never lights up even when you force the piston to the end, your internal piston magnet has demagnetized or fallen off. Time to rebuild the cylinder, not buy more sensors.Can I use this with 110V AC?
Absolutely not. This is a low-voltage DC reed switch. Hook it up to 110V and it will arc internally and become a very expensive paperweight. Use the CS11TA or similar AC-rated switch for line voltage.
