FH20 Series New Energy Relay: A High-Reliability Switching Solution for New Energy and Charging Facilities

Core Advantages: Safe, Efficient, and Heat-Resistant

Adequate Contact Gap to Meet Photovoltaic Safety Standards

The contact gap after the relay opens directly affects isolation safety. The FH20 series features a contact gap of ≥2.0 mm, which fully complies with the IEC 62109-2-2011 standard “Safety requirements for power converters for use in photovoltaic power systems.” For photovoltaic inverters, this standard is mandatory. The 2.0 mm gap ensures effective arc interruption even under overvoltage conditions, protecting downstream circuits and operator safety.

Hold-after-Start Voltage Reduction to Significantly Lower System Power Consumption

The FH20 employs a working strategy that reduces the coil voltage after initial pickup. Once the relay is closed, only a lower coil voltage is needed to maintain the contact state, substantially reducing coil power consumption compared to continuous fullvoltage drive. For example, with the 12 V model, the holding power is far lower than the 1400 mW required for pick-up. This feature is especially beneficial for chargers and inverters that require long standby or continuous operation, effectively lowering system temperature rise and energy loss.

UL Class F Insulation System for Higher Temperature Tolerance

The heat resistance rating of the insulation system determines relay life under high-temperature conditions. The FH20 series uses a UL-recognized Class F insulation system, allowing a maximum coil hotspot temperature of 155 °C—25 °C higher than the common Class B (130 °C). This means that at an ambient temperature of 85 °C, the relay still has ample thermal margin, making it particularly suitable for equipment installed in enclosed, poorly ventilated, or outdoor high-temperature environments.

Environmentally Friendly Materials, RoHS Compliant

From contacts to housing, the product uses materials that meet RoHS requirements, free from lead, mercury, hexavalent chromium, and other hazardous substances, ensuring barrierfree export to regions with strict environmental regulations, such as the EU.

Load Capability and Electrical Parameters

The FH20 series adopts a 1A contact arrangement (single-pole single-throw, normally open), with AgSnO₂ (silver tin oxide) contact material. This material offers excellent resistance to welding and arc erosion, making it particularly suitable for frequent switching of high-current resistive loads.

The key electrical ratings are summarised in the table below:

The low contact resistance ensures minimal conduction loss, while the high dielectric strength provides ample safety margin for high‑low voltage isolation. The operate and release times meet the response speed requirements of most industrial control and power electronics applications.

Coil Specifications and Selection Guide

The FH20 offers multiple standard coil voltages from 5 V to 24 V, all with a rated power of 1400 mW. The key electrical parameters for commonly used models are summarised below for quick matching to your system control voltage:

Selection tip: The operate voltage is the minimum required for reliable pick-up; the drive voltage should be designed not to fall below this value. The release voltage determines the sensitivity for dropout upon power-off. If ultra-low power consumption is critical, a higher coil voltage (e.g., 24 V) may be chosen, as its operating current is lower, and combined with the hold-after-start feature, total power consumption can be further reduced.

Mechanical Robustness and Environmental Adaptability

New energy equipment often faces vibration, shock, and wide temperature variations. The FH20 series excels in mechanical performance:

Shock resistance: Functional shock up to 196 m/s² (20 g), destructive shock up to 980 m/s² (100 g), sufficient to withstand accidental impacts during transport and installation.

Vibration resistance: 10 Hz ~ 55 Hz at 1.5 mm amplitude, ensuring stable operation near vibration sources such as fans and compressors.

Operating temperature range: -40 °C ~ +85 °C, covering outdoor conditions in most regions of China; humidity tolerance from 5 % to 85 % for damp environments.

In terms of endurance, the mechanical life is 2×10⁵ operations, while the electrical life (resistive load, 32 A 250 VAC, ON/OFF = 1 s / 9 s) reaches 3×10⁴ operations, satisfying several years of normal use in chargers, inverters, and similar equipment.

Enclosure Styles and Environmental Selection

The FH20 is available in two internal protection types, allowing you to choose according to the cleanliness of the actual working environment:

Flux proofed type: Suitable for clean indoor environments free from corrosive gases (H₂S, SO₂, NO₂, etc.) and conductive dust. This type prevents flux ingress during soldering and offers cost advantages.

Plastic sealed type: Recommended for unclean environments that may contain corrosive gases or dust, such as industrial sites or outdoor cabinets. The sealed construction more effectively isolates external contaminants, ensuring longterm low contact resistance.

Both types share the same external dimensions: 30.3 mm (L) × 15.4 mm (W) × 23.1 mm (H). They are designed for standard PCB pin mounting and weigh approximately 20.7 g. PCB layout tolerances should be controlled within ±0.1 mm; for outline dimension tolerances, please refer to the detailed notes in the datasheet.

International Approvals at a Glance

The FH20 series has obtained the necessary safety certifications for major global markets, facilitating export of your end products:

All three certifications use AgSnO₂ contacts and cover both continuous 32 A and maximum 35 A ratings at a temperature class of 85 °C, ensuring compliance under extreme operating conditions.