Universal Fan Relay SD90370 by Supplying Demand 24VAC SPDT HVAC Relay

Description

Product Overview

The Supplying Demand SD90370 universal fan relay is a purpose‑built component designed to meet the demanding requirements of modern HVAC and refrigeration systems. Featuring a single‑pole double‑throw (SPDT) configuration, this relay delivers precise control of 24VAC circuits, enabling reliable fan operation across a wide range of temperature and pressure conditions. Its robust construction incorporates high‑quality contact materials that are rated for 12 A at 125 VAC and 8 A at 250 VAC, ensuring long‑term durability even in high‑cycle environments.

Physically, the relay measures 3 × 1.75 × 1.5 inches and weighs a negligible 0.01 ounces, making it an ideal fit for compact control panels where space is at a premium. The device is housed in a clear, impact‑resistant enclosure that protects internal components from dust, moisture, and vibration, while still allowing easy visual inspection of the relay status during routine maintenance. The SD90370 model number is clearly stamped on the housing, simplifying inventory management and replacement part identification.

From an electrical perspective, the relay operates on a 24VAC control voltage, a standard in most commercial and residential HVAC applications. This voltage level provides a safe, low‑power signal that can be driven by thermostats, control boards, or external sensors without the need for additional step‑down transformers. The SPDT switching action enables the relay to toggle between two distinct circuit paths, offering flexibility for fan speed control, system sequencing, or safety interlock functions.

In addition to its core functional attributes, the SD90370 includes several design enhancements that improve installation and serviceability. The relay terminals are clearly labeled and feature a screw‑type connection that secures wiring against loosening due to vibration. The component also incorporates a built‑in LED indicator that provides immediate visual feedback on the relay’s operational state, helping technicians quickly verify proper function during troubleshooting.

Overall, the Supplying Demand SD90370 universal fan relay combines compact size, reliable performance, and user‑friendly features to deliver a versatile solution for a broad spectrum of HVAC and refrigeration applications. Whether retrofitting an older system or specifying components for a new installation, this relay offers the confidence of a proven design backed by a reputable manufacturer.

Usage

This relay is ideally suited for use in air handling units, furnace blowers, condenser fans, and evaporator coil fans across residential, commercial, and industrial settings. Its 24VAC control capability aligns with standard thermostat outputs, allowing seamless integration with existing control strategies without the need for additional wiring modifications. Installers can employ the SD90370 in both new construction projects and retrofit scenarios, where space constraints often dictate the selection of low‑profile components.

In commercial refrigeration environments, the relay’s ability to handle up to 60 LRA at 125 VAC ensures that high‑current fan motors can be reliably switched without overheating or premature wear. This makes it an excellent choice for walk‑in coolers, display cases, and large‑scale cold storage facilities where continuous fan operation is critical to maintaining temperature stability. The relay’s quick response time also supports advanced control algorithms that modulate fan speed based on real‑time temperature and humidity data, contributing to energy efficiency and reduced operating costs.

For residential HVAC systems, the SD90370 provides a straightforward solution for fan control in furnaces and air conditioners. Homeowners and service technicians benefit from the relay’s easy‑to‑install design, which reduces installation time and minimizes the risk of wiring errors. The clear labeling of terminals and the inclusion of a status LED simplify routine checks, allowing for rapid verification of proper operation during seasonal maintenance visits.

Industrial applications such as process cooling, ventilation, and exhaust systems also gain from the relay’s robust construction. The device’s resistance to dust, moisture, and vibration makes it suitable for harsh environments where reliability is paramount. When paired with programmable logic controllers (PLCs) or building automation systems, the SD90370 can be used to orchestrate complex fan sequencing, ensuring optimal airflow distribution while protecting equipment from overload conditions.

Regardless of the specific application, it is essential to disconnect power before servicing the relay to ensure safety. The product documentation provides clear guidance on proper handling procedures, and the relay’s design includes protective features that help prevent accidental activation during maintenance activities.

Why Choose Us

Supplying Demand has built a reputation for delivering high‑quality HVAC components that meet rigorous industry standards. Each relay undergoes comprehensive testing for electrical performance, mechanical durability, and environmental resistance, guaranteeing that the SD90370 performs reliably throughout its service life. Our commitment to quality is reflected in the product’s 4.6‑star rating from over 40 verified customer reviews, highlighting satisfaction with performance, ease of installation, and long‑term reliability.

Choosing the SD90370 means benefiting from a component that is compatible with major HVAC brands, yet it is always advisable to verify fitment with the specific equipment in use. Our technical support team is readily available to assist with fitment questions, wiring diagrams, and troubleshooting guidance, ensuring that you have the resources needed to achieve a successful installation. We also provide detailed documentation, including wiring schematics and safety instructions, to help streamline the integration process.

In addition to product quality, Supplying Demand offers a comprehensive after‑sales service program. Should you encounter any issues, our warranty coverage and responsive customer service team are prepared to address concerns promptly. This dedication to customer satisfaction sets us apart from competitors and reinforces the confidence that professionals place in our products for critical HVAC applications.

Key Features

• Compact 3 × 1.75 × 1.5 in design fits tight control panels, saving valuable space.
• Reliable 24VAC SPDT switching ensures precise fan control for HVAC and refrigeration systems.
• High‑current contacts rated up to 12 A at 125 VAC provide durability in demanding applications.
• Clear terminal labeling and LED status indicator simplify installation and troubleshooting.
• Supported by Supplying Demand’s responsive customer service and warranty for peace of mind.

FAQ

What voltage and current ratings does the SD90370 support?

The relay is designed for a 24VAC control voltage. It can handle up to 12 A at 125 VAC (FLA) and 8 A at 250 VAC, with corresponding locked‑rotor ampere (LRA) ratings of 60 LRA and 48 LRA respectively.

Is the relay compatible with all HVAC brands?

While the SD90370 is engineered to be compatible with a wide range of major HVAC manufacturers, it is always recommended to verify the specific model and mounting requirements of your equipment before purchase.

Can this relay be used in industrial refrigeration systems?

Yes, the relay’s robust construction and high current capacity make it suitable for industrial refrigeration applications, including walk‑in coolers and large‑scale cold storage units where reliable fan operation is essential.

What safety precautions should be taken during installation?

Always disconnect power to the circuit before handling the relay. Follow the wiring diagram provided in the product documentation, and ensure that connections are secure to prevent accidental contact or arcing.

What warranty does Supplying Demand provide for this relay?

Supplying Demand offers a standard limited warranty that covers manufacturing defects for a specified period. For detailed warranty terms and support options, please contact our customer service team or refer to the warranty documentation included with the product.