47. MOV for 3-Phase Line-to-Line Surge Protection

A 3-phase 415VAC motor drive is subject to heavy surge transients from motor switching, VFD commutation, contactor operations, and lightning on the power distribution system.

MOVs are placed across each line-to-line pair (L1-L2, L2-L3, L3-L1) to clamp these transients. Each MOV must be rated for the full 415VAC line-to-line voltage.

The standard MOV rating for 415VAC is 460VAC maximum continuous. This provides headroom above 415V nominal (including up to +10% grid tolerance = ~457V) while still clamping effectively.

High surge current (≥10kA) and energy (≥250J) ratings are required because industrial 3-phase environments produce very high-energy transients.

Required: 460VAC · ≥10kA surge · ≥250J · 1-Circuit · Disc · Through Hole · Littelfuse · RoHS

Go to DigiKey.com → Circuit Protection → Varistors, MOVs

Apply these filters:

• Maximum AC Volts → 460V
• Current - Surge → 10kA or higher
• Energy → 250J or higher
• Number of Circuits → 1
• Mounting Type → Through Hole
• Package / Case → Disc
• Manufacturer → Littelfuse Inc.
• Part Status → Active

Note: You need 3 identical MOVs (one per line-to-line pair). The user selects the correct single MOV component; the BOM quantity is 3.

Tip:  Larger disc sizes (14mm, 20mm) offer higher surge current and energy ratings. DigiKey shows disc size in the Package / Case field (e.g., "Disc 14mm" or "Disc 20mm"). For ≥250J, you will likely need a 20mm disc MOV.

The filtered list will show matching parts. Before you pick one, check: Is it Active? Is stock available? Is the manufacturer reputable? Is a datasheet available?

Full checklist: How to Select a Safe, Production-Ready Component — EWskills Guide

➡ View Matching Parts — Littelfuse, MOV, 460VAC, ≥10kA, ≥250J, Disc