Products
Products
Installation & Application（安装应用） 
Installation Precautions
Connection Method
The SPD must be connected in series between the signal channel and protected equipment.
Wiring Direction
IN port: Connect to the signal channel
OUT port: Connect to the protected equipment (must be installed close to the device)
Warning: Reverse connection will disable protection
Grounding Requirement
Securely connect the SPD's ground wire to the lightning protection system's grounding busbar
Max. ground wire length: 1m (shorter = better performance)
Maintenance
No routine maintenance required
Mandatory inspections:
• Before thunderstorm seasons
• During periods of frequent lightning activity
Product Dimension Drawing（mm）
Installation Wiring Instructions
Product Schematic Diagram
Technical Parameters（技术参数） | Parameter | Specification |
|---|---|
| Model | NKT-4 |
| Operating Voltage | 24V DC |
| Max. Continuous Operating Voltage (Uc) | 33V DC |
| Voltage Protection Level (Up) | • C2 (X-PE): ≤100V • C2 (X-X): ≤75V • C3 (X-PE): ≤50V • C3 (X-X): ≤50V |
| D1 Impulse Discharge Current | 2.5kA (10/350µs) |
| C2 Total Nominal Discharge Current | 20kA (8/20µs) |
| C2 Per-line Nominal Discharge Current | 5kA (8/20µs) |
| Series Impedance per Line | 1.8Ω |
| Cut-off Frequency | 7.8MHz |
| Rated Current | 0.75A |
| Capacitance (X-PE) | ≤15nF |
| Operating Temperature | -40℃ to +80℃ |
| Enclosure Material | PA66 |
| Design | Replaceable failure module |
| Dimensions (W×H×D) | 90mm × 12.5mm × 74.5mm |
Ordering and Model Selection（订货选型） | Product model | Product description |
|---|---|
| NKT-4 Low-Frequency Signal Surge Protective Device | The device utilizes a standard terminal block interface to integrate protection circuits for telephone, power MODEM, and digital/analog signals into a single unit。 |
*Please send the inquiry email containing specific product requirements (such as model, quantity, technical parameters, etc.) to the designated email address salina@kejia.com.
（请将包含具体产品需求（如型号、数量、技术参数等）的询价邮件发送至指定邮箱 salina@kejia.com）
