Phoenix VAL-MS Series Surge Protection Devices (SPD) Selection Guide: 350V-500V Voltage Class

Opening: Targeted Surge Protection for Medium-Voltage Industrial Power Systems

The Phoenix VAL-MS series continues to expand its medium-voltage portfolio (350V-500V), covering single-phase/three-phase configurations (1+1, 2+0, 3+0, 3+1, 4+0), diverse terminal types (screw / 叉形), and remote monitoring (FM) functions. These SPDs comply with IEC 61643-11 standards, feature fast response time (≤25ns), and industrial-grade durability (-40°C to +70°C), providing reliable overvoltage protection for factory power distribution, mechanical equipment, and critical control systems. This guide structures part number-model correspondence, core parameters, and scenario recommendations to simplify selection and procurement.

I. Core Advantages of This Voltage Class (350V-500V)

• Wide voltage adaptation: Covers 350V/385V/400V/500V, matching medium-voltage industrial power systems (e.g., 400V three-phase mains, 385V DC link).
• Flexible configurations: Supports 1+1 (single-phase+earth), 2+0 (single-phase+PEN), 3+0 (three-phase+PEN), 3+1 (three-phase+neutral+earth), 4+0 (special three-phase), adapting to different grounding systems.
• Dual terminal options: Screw terminals (ST suffix) for standard wiring, fork-type terminals (VF suffix) for quick connection, enhancing installation efficiency.
• Intelligent monitoring: FM suffix models integrate remote indication contacts, enabling real-time status monitoring (normal/fault) for critical systems.
• Special design variants: Universal design (UD), narrow-width (RW), and color-coded (GY gray) models, adapting to space-constrained cabinets and visual identification needs.

II. Complete Product Selection Table (Part Number + Model + Core Information)

1. 500V Voltage Class: High-Voltage Medium-Voltage Systems

2. 400V Voltage Class: Industrial Standard Medium-Voltage Systems

3. 385V Voltage Class: Precision Medium-Voltage Systems (with Discharge Current Rating)

4. 350V Voltage Class: Low-Medium Voltage Systems

III. VAL-MS 350V-500V Nomenclature Decoding

VAL-MS [Voltage]/[Discharge Current]/[Configuration]-[Feature]

• Voltage: 350/385/400/500 → System voltage adaptation (AC/DC compatible unless specified).
• Discharge Current: 40/65/80 → Max discharge current (kA), omitted = standard 20kA.
• Configuration:
  • 3+1 = Three-phase + neutral + earth (three-phase four-wire);
  • 3+0 = Three-phase + PEN (three-phase three-wire);
  • 2+0 = Single-phase + PEN (single-phase three-wire);
  • 1+1 = Single-phase + earth (single-phase two-wire);
  • 4+0 = Special three-phase (custom configuration);
  • Omitted = Universal (compatible with multiple configurations).
• Feature:
  • FM = Remote monitoring contact;
  • VF = Fork-type terminals;
  • ST = Screw terminals;
  • UD = Universal design (multi-wiring compatibility);
  • RW = Narrow width (space-saving);
  • GY = Gray color (visual identification);
  • /3 = Abbreviation for 3+0 configuration.

IV. 3-Step Quick Selection Technique

Step 1: Confirm System Voltage & Discharge Current

• System Voltage: 350V (low-medium) → 350V series; 385V (precision) → 385V series; 400V (industrial standard) → 400V series; 500V (high-medium) → 500V series.
• Discharge Current:
  • High-surge (motors/inverters) → 80kA (385/80 sub-series);
  • Medium-surge (general industrial) → 65kA (385/65 sub-series);
  • Low-surge (cleanroom/lab) → 40kA (385/40 sub-series);
  • Standard → Omitted (20kA).

Step 2: Select Configuration Based on Grounding System

• Three-phase four-wire (L1-L3+N+PE): 3+1 configuration (e.g., 2920968, 2858632).
• Three-phase three-wire (L1-L3+PEN): 3+0 configuration (e.g., 2910476, 2921006).
• Single-phase two-wire (L+PE): 1+1 configuration (e.g., 2921284, 2921242).
• Single-phase three-wire (L+N+PEN): 2+0 configuration (e.g., 2910112).
• Special three-phase: 4+0 configuration (e.g., 2920845).

Step 3: Choose Terminals & Special Functions

• Terminal Type:
  • Standard wiring → ST (screw terminals, e.g., 2807609);
  • Quick wiring → VF (fork terminals, e.g., 2856579).
• Space Constraint: Narrow cabinets → RW (narrow width, e.g., 1050280).
• Remote Monitoring: Critical systems → FM (e.g., 2920751, 2920968).
• Visual Identification: Multi-device differentiation → GY (gray, e.g., 2800472).
• Universal Compatibility: Mixed wiring systems → UD (e.g., 2910112).

V. Recommended Industry-Scenario Combinations

VI. Selection Pitfall Avoidance Guide

1. Voltage Mismatch: 400V system using 350V SPD → Confirm system voltage (350/385/400/500) to avoid overvoltage damage.
2. Configuration Error: Three-phase four-wire system using 3+0 SPD → Select 3+1 for separate N/PE, 3+0 only for PEN (combined neutral/earth).
3. Discharge Current Insufficiency: High-surge environments (near motors) using 40kA SPD → Choose 65kA/80kA models (385/65/385/80 sub-series).
4. Terminal Type Error: Quick-wiring projects using ST terminals → Select VF (fork terminals) for faster installation.
5. Space Neglect: Compact cabinets using standard-width SPD → Opt for RW (narrow width) models (e.g., 1050280) to save 30% space.
6. Monitoring Oversight: Critical systems without FM → Add FM suffix models for remote fault alerting (e.g., 2920751).
7. Color Coding Ignorance: Multi-voltage systems without visual differentiation → Use GY (gray) models (e.g., 2800472) for easy identification.

Conclusion: Select the Right VAL-MS SPD for Medium-Voltage System Protection

The Phoenix VAL-MS 350V-500V series provides targeted surge protection for medium-voltage industrial systems, with flexible configurations, terminal options, and monitoring functions adapting to diverse power systems and installation environments.