ENMG / SURGE SUPPRESSION
SQ1 / SQ3
RC contact and load surge suppressors
Passive resistor-capacitor networks for reducing switching transients across suitable AC contacts or loads.
Request a quote ↗TECHNICAL DATA / SQ1 / SQ3
Specifications & selection.
- Single-phase SQ1-351S and three-phase SQ3-511S standard models.
- 0.47 μF capacitance per RC branch with 100 Ω / 2 W resistance.
- Compact surface-mount enclosure with covered screw terminals.
| Parameter | SQ1-351S | SQ3-511S |
|---|---|---|
| Application | Single phase | Three phase; three RC groups |
| Rated AC voltage | 300 VAC | 550 VAC |
| Frequency | 50/60 Hz | 50/60 Hz |
| Capacitance per branch | 0.47 μF | 0.47 μF |
| Resistance / power | 100 Ω / 2 W | 100 Ω / 2 W |
| Published transient notation | 900 Vp-p / 1 ms | 1500 Vp-p / 1 ms |
| Outline, H × W × L | 68 × 17 × 65 mm | 68 × 17 × 65 mm |
| Approximate mass | 60 g | 60 g |
| Parameter | Specification |
|---|---|
| Terminals | Barrier M3; 7.62 mm pitch; 0.8 N·m, maximum 1.0 N·m |
| Wire cross-section | 0.5–1.5 mm² |
| Surface fixing | Two M4 screws; 54 mm hole pitch; 1.2–1.5 N·m |
| Dielectric strength | 2500 VAC, 50/60 Hz, 1 minute; test points not specified |
| Insulation resistance | 100 MΩ at 500 VDC |
| Operation / storage | −25 to +70 °C / −45 to +120 °C; no icing |
| Humidity | ≤90% RH, no condensation |
Selection & installation notes
- Connect only in the parallel arrangement specified for the exact application; this is a passive suppressor, not a series power switch or replacement for upstream protection.
- The source describes three independent RC groups but elsewhere mentions a common-neutral arrangement. Confirm the SQ3 terminal diagram and system wiring before connection.
- The optional-component discussion mentions 275 VAC X2 capacitors; that component figure does not verify a 550 VAC assembly. Confirm the ordered assembly voltage.
- The transient figures are reproduced as Vp-p / 1 ms and must not be read as RMS or continuous voltage ratings.
- High switching frequency increases resistor heating. Confirm RC values and thermal suitability for the actual contact or load; life improvement depends on the application.
Based on the official Chinese product page and selection charts ↗. Checked 2026-09-15. Confirm the current specification for the exact model when ordering.
TECHNICAL RESOURCES
Plan your integration.
ENMG electrical accessories — English product-family brochure.
This is a product-family brochure. Request a model-specific datasheet and installation drawing with your inquiry.