Key Technical Specifications

• Product Model: CS4HB
• Manufacturer: KOGANEI
• Product Type: Magnetic Position Sensor (Reed Switch)
• Wiring Configuration: 2-Wire (Non-polarized)
• Switching Element: Reed Contact
• Indicator: Built-in LED for switching confirmation
• Mounting Style: Direct Mount (T-slot or band mount)
• Protection Rating: IP67 (Verify with OEM manual)
• Operating Temperature: -10°C to +60°C (Typical for this series)

 

Product Introduction

I’ve replaced hundreds of these CS4HB switches on the factory floor, usually because someone backed a forklift into the cylinder or the reed contacts finally welded shut after a million cycles. This is a standard 2-wire magnetic reed switch from KOGANEI, designed to slide right into the T-slot of a pneumatic cylinder and tell your PLC that the piston has reached its end of stroke. It’s a simple, passive device, but when it fails, your entire automated sequence stops dead.Engineers keep these in the spare parts crib because they’re the bread-and-butter of pneumatic sensing. The 2-wire design means you don’t have to worry about PNP/NPN polarity, and the built-in LED lets you troubleshoot without pulling out a multimeter. Just be careful with the wiring: these 2-wire switches have a small leakage current (usually a few mA) that can ghost-trigger sensitive PLC inputs if you’re not careful. I’ve seen guys wire these up and swear the switch was stuck ON, only to find out the PLC input card was seeing the leakage current. Always check your PLC’s minimum input threshold.

Quality SOP & Tech Pitfalls

The Lab Report:
I don’t just eyeball these. Here is the actual test protocol before a CS4HB ships:

1. Visual Inspection: Check the housing for cracks and the cable for fraying. Reed switches are glass inside; one drop on concrete and they’re toast.
2. Magnetic Test: We slide it over a test cylinder with a known-good magnet. The LED must snap on/off crisply. No flickering, no hesitation.
3. Electrical Check: Fluke 115 in series to verify leakage current is under spec. We also check contact resistance when closed (should be <1 ohm).
4. Pull Test: We give the cable a gentle tug. Factory crimps fail; we catch them before you do.
5. ESD Sealing: Anti-static bag, even though it’s just a reed switch. Better safe than sorry.

The Engineer’s Warning:
The #1 killer of these switches isn’t electrical; it’s mechanical. I’ve seen techs overtighten the mounting screw and crack the plastic housing, letting coolant seep in. Within a week, the reed contacts corrode and the switch fails. Hand-tighten only. Also, if you’re replacing a failed CS4HB, check the cylinder itself. Sometimes the piston magnet degrades, and no amount of new switches will fix it. I once spent three hours swapping sensors on a cylinder that had lost its magnetic field. Don’t be that guy.

 

Installation & Configuration Guide

1. Pre-Installation Safety: ⚠️ Lock out/tag out the pneumatic supply. Vent the cylinder. You do not want that piston moving while your fingers are near the T-slot. Take a photo of the old switch’s orientation.
2. Removal: Loosen the mounting screw (usually a small Allen head). Slide the old CS4HB off the cylinder. Inspect the T-slot for debris or metal shavings.
3. Installation: Slide the new switch onto the cylinder. Do not tighten the screw yet. Manually stroke the cylinder (or jog it via PLC) to find the exact trip point. The LED should illuminate precisely at the end of stroke. Once positioned, hand-tighten the screw.
4. Power-On & Testing: Restore air and power. Cycle the cylinder 5-10 times. Watch the LED. Verify the PLC input status matches. If the LED flickers, the switch is too loose or the magnet is weak. Adjust and re-test.

Compatible Replacement Models

• ✅ Drop-in Replacement: KOGANEI CS4HB – Exact match. Verify cable length and connector type.
• ⚠️ Software Compat.: KOGANEI CS4HA / CS4MA – Same series, different suffix. Usually interchangeable, but check the datasheet for leakage current and switching capacity differences. May require PLC input threshold adjustment.
• ❌ HW Mod Req.: Solid-State Magnetic Switches – Different technology entirely. Requires rewiring and possibly a new power supply. Do not substitute unless doing a full sensor upgrade.

 

Frequently Asked Questions (FAQ)

Can I use a 3-wire NPN/PNP switch instead of this 2-wire?
You can, but you’ll need to rewire the PLC input and possibly change the power supply. The CS4HB is 2-wire, which is simpler but has leakage current. If your PLC supports 3-wire inputs and you’re tired of ghost signals, upgrading to a 3-wire solid-state switch is worth the 10 minutes of rewiring.My switch LED is on all the time. Is it bad?
Maybe. First, check if the piston is actually at the end of stroke. If it is, and the LED stays on when the piston retracts, the reed contacts have welded shut. Replace it. If the LED is dimly lit when the piston is away, that’s leakage current. Check your PLC’s input impedance.How long do these actually last?
In a clean, dry environment? Millions of cycles. In a wet, dirty, vibrating environment? Maybe six months. The reed contacts are mechanical; they wear out. If you’re replacing them every few months, look at solid-state (hall effect) alternatives. They cost more but last forever.Is this switch polarized?
No. The CS4HB is a 2-wire non-polarized reed switch. You can connect it either way. Just make sure your PLC input card can handle the leakage current.Can I adjust the trip point?
Yes, that’s the whole point of direct-mount switches. Slide it along the cylinder body to fine-tune the activation position. Lock it down once you find the sweet spot.What if I can’t find the exact CS4HB?
Check the CS4HA or CS4MA. KOGANEI’s naming convention can be confusing, but these are often functionally identical. Always verify the datasheet for electrical specs before substituting. I’ve seen “equivalent” switches with different leakage currents cause weeks of troubleshooting.