Product Overview

The SLP32D belongs to the cost-effective SLP range for digital and analog I/O protection. Each module protects two process loops or one 4-wire circuit. A multi-stage hybrid circuit combines solid-state electronics with a gas discharge tube (GDT). Consequently, this device handles maximum surge currents up to 20kA (8/20µs waveform). The SLP32D adds only 2 ohms loop resistance to your measurement circuit. For this reason, it suits low-power and high-accuracy applications perfectly. Fully automatic operation means the device resets itself after each surge event. Additionally, a 10-year product warranty backs every correctly installed unit.

Technical Specifications

General SLP Range Specifications

• Maximum Surge Current: 20kA (8/20µs waveform) per line

• Leakage Current: <1µA @ working voltage

• Maximum Rated Load Current: 1.50A

• Loop Resistance: 2 ohms

• Capacitance (Line to Line): 60pF

• Attenuation: -0.1dB @ 9kHz - 37MHz, -3dB @ 50MHz

• Response Time: <1ns

• Ambient Temperature (Working & Storage): -40 to +80°C

• Humidity: 5 to 95% RH (non-condensing)

• Terminals: 2.5mm² (12 AWG)

• Electrical Connections: Plug/header screw terminal strip

• Mounting: T-section DIN-rail (35 x 15mm rail)

• Weight: 140g approximately

• Case Flammability: UL94-V0

• Degree of Protection: IP20

Model SLP32D Specific Parameters

Categories Tested

The SLP32D has passed multiple test categories. These include A2, B2, C1, C2, C3, and D1. Accordingly, this device meets rigorous international standards for surge protection.

Key Features & Benefits

Hybrid Protection Circuit

The SLP32D uses a multi-stage hybrid protection network. Solid-state electronics provide fast clamping. A gas filled discharge tube (GDT) handles high-energy surges. Together, they deliver 20kA surge current capacity. This circuit adds only a tiny voltage drop to your loop. Consequently, normal operation remains unaffected.

High Packing Density

Each SLP32D module protects two complete process loops. You save valuable DIN rail space compared to single-loop protectors. For large control cabinets, this density matters significantly.

Automatic Operation

The SLP32D reacts immediately to any surge event. Response time stays below 1 nanosecond. Surge currents redirect safely to earth. Output voltages clamp to safe levels. After the surge passes, the device resets automatically. No manual intervention is required.

High Bandwidth Performance

Bandwidth reaches 50MHz with only -0.1dB attenuation up to 37MHz. Therefore, the SLP32D works perfectly with high-speed communication systems. Examples include fieldbus networks and fast digital I/O.

Simple DIN Rail Mounting

One simple manual operation clamps the module securely onto T-section DIN rail. The same action automatically provides a high-integrity earth connection. For adverse environments, a specially-plated rail version is available.

Installation Guidelines

Follow these steps for proper installation of the SLP32D.

1. Mount the unit onto T-section DIN rail (35 x 15mm).

2. Push the clamping mechanism until you hear a click. This action secures the device and creates the earth connection.

3. Connect the field side wiring to the input terminals using 2.5mm² wire.

4. Connect the protected equipment side to the output terminals.

5. Verify the earth connection is clean and low-resistance.

6. Power up the system and check for normal signal transmission.

7. Test the installation with a loop resistance measurement if needed.

Note: The SLP32D requires no external power or configuration. For adverse environments, consider using the specially-plated DIN rail option.

Packaging List

• One SLP32D Surge Protection Module

• One product quick start guide

• One set of terminal screw plugs

• One anti-static protective bag

Common FAQs

1. How many process loops does one SLP32D protect?

Each SLP32D module protects two complete process loops. Alternatively, you can use it for one 4-wire circuit. For large systems, this high density saves significant cabinet space.

2. What happens if the SLP32D sees a surge beyond 20kA?

The device withstands overstressed fault mode testing at 22kA with in=3kA. However, repeated over-stressing may eventually degrade protection. The 10-year warranty covers correctly installed units against failure.

3. Does the SLP32D affect my 4-20mA loop accuracy?

No, the SLP32D adds only 2 ohms series resistance and <1µA leakage current. For a typical 4-20mA loop, this adds negligible error. High accuracy applications see virtually no impact.

4. Can I use the SLP32D on high-speed communication networks?

Yes, bandwidth reaches 50MHz with only -0.1dB attenuation at 37MHz. Consequently, the SLP32D suits fieldbus, Profibus, and other fast digital protocols. Many standard protectors cannot achieve this bandwidth.

5. How do I know if the SLP32D has failed after a large surge?

The device has no moving parts or status indicator. For this reason, we recommend periodic loop resistance checks. If loop resistance increases significantly above 2 ohms per line, replace the unit. The 10-year warranty simplifies replacement.

Why Choose This Module?

The SLP32D offers the best cost-to-performance ratio for process I/O surge protection. Its hybrid circuit handles 20kA surges while adding only 2 ohms resistance. High packing density protects two loops per module. Bandwidth reaches 50MHz for modern communication systems. Automatic reset means no field intervention after surges. The 10-year warranty provides peace of mind. For reliable, low-resistance surge protection, choose the SLP32D.