Product Summary
The SS4301T02 is a precise low-side sense CHARM for 24V DC dry contacts. It reliably detects discrete input states from sensors or switches. This module uses a constant wetting voltage of 22.5 Volts. Engineers trust this CHARM for accurate and safe signal acquisition.
Expert Technical Evaluation & Performance Review
Precise Dry Contact Detection
The SS4301T02 uses a 4.8 kΩ channel impedance for accurate sensing. It detects an “On” state when current exceeds 2.25 mA. This corresponds to a contact resistance below 5.3 kΩ. The module sees an “Off” state when current drops under 1.75 mA. This indicates a resistance higher than 8.2 kΩ. These thresholds provide a clear and reliable switching window.
Integrated Fault Detection Logic
This CHARM supports optional fault detection with an external resistor pack. Without this resistor, fault detection remains unavailable. With the resistor installed, the module distinguishes three circuit conditions. A short circuit is guaranteed below 100 Ω. A good status is recognized between 400 Ω and 40 kΩ. An open circuit is guaranteed above 75 kΩ. This logic helps operators quickly identify wiring or sensor failures.
Robust Electrical Protection
The field circuit features a 12.5 mA current limiting circuit for safety. This protects the CHARM and connected field wiring from overcurrent. The wetting voltage is stable at 22.5 Volts (± 5%). This voltage is current limited to a nominal 12.5 mA. Each CHARM consumes a maximum of 18 mA from the 24V DC power supply. The module dissipates only 0.33 Watts of heat, ensuring cool operation.
Configurable Channel for Slow Signals
The SS4301T02 configures as a discrete input for dry contacts. It works perfectly with discrete state sensors changing slower than 2 Hz. This makes it ideal for monitoring limit switches or pushbuttons. The module includes a field wiring disconnect for safe maintenance. You can isolate the field wiring without removing the CHARM.
Low-Side Sense Topology
This CHARM uses a low-side sense (LS) topology for dry contacts. This design connects the load between the power supply and the input. It provides a common ground reference for multiple input channels. This topology is standard for many industrial control panels.
Logistics & Standard Packaging Details
- One (1) Emerson SS4301T02 Low-Side Sense CHARM.
- Product is shipped in an anti-static protective bag.
- Includes necessary documentation for installation.
- Express delivery is available via FedEx, UPS, and DHL.
