Packard PR340 DPDT 24 Volt Coil Switching Relay Industrial Switch

Description

Product Overview

The Packard PR340 DPDT 24V coil switching relay is engineered to meet the rigorous demands of modern industrial applications. Its compact DIP form factor measures just 2.5 by 2.4 by 1.7 inches, allowing seamless integration into tight panel spaces while delivering robust performance. Constructed with high‑quality copper contacts and a durable polymer housing, the relay ensures consistent operation over thousands of cycles. The 24‑volt coil provides a reliable actuation voltage that is compatible with standard control circuits found in heat pumps, vending machines, fans, and HVAC equipment. With a rated switching capacity suitable for medium‑load loads, the PR340 balances power handling with precise control, making it an ideal choice for engineers seeking dependable switching solutions.

Designed for ease of installation, the relay features six clearly labeled terminals arranged in two rows: terminals 1‑2‑3 for the first pole and terminals 4‑5‑6 for the second pole. This DPDT configuration enables users to switch both the normally open and normally closed contacts simultaneously, simplifying circuit design and reducing wiring complexity. The relay’s coil resistance and inductance are optimized to minimize power consumption while delivering fast response times, ensuring that connected loads activate promptly when control signals are applied. Additionally, the PR340 complies with industry standards for safety and electromagnetic compatibility, providing peace of mind for system integrators who must adhere to strict regulatory requirements.

Usage

In heating, ventilation, and air‑conditioning (HVAC) systems, the PR340 serves as a critical control element that toggles compressors, fans, and valve actuators with precision. Its 24‑volt coil matches the common control voltage used in thermostats and building management systems, allowing seamless communication between sensors and mechanical components. For vending machine manufacturers, the relay offers a reliable method to power coin acceptors, product dispensers, and refrigeration units, reducing the risk of downtime caused by faulty switching. Heat pump installations benefit from the DPDT arrangement, which can reverse motor direction or switch between heating and cooling stages without requiring additional relays, thereby conserving board space and simplifying maintenance.
The relay’s rugged construction also makes it suitable for outdoor or semi‑exposed environments where temperature fluctuations and dust are concerns. Its polymer enclosure resists moisture ingress, while the internal contacts are coated to prevent oxidation, extending service life even in harsh conditions. Technicians appreciate the clear terminal markings, which speed up troubleshooting and replacement procedures. Because the PR340 is not discontinued by the manufacturer, spare parts remain readily available, supporting long‑term asset management strategies for facilities that rely on continuous operation of critical equipment.

Why Choose Us

Choosing the Packard PR340 means selecting a product backed by decades of engineering expertise in industrial switching technology. Packard’s reputation for quality is reflected in the relay’s stringent testing processes, which include thermal cycling, contact resistance verification, and endurance testing up to one million operations. This commitment to durability translates into lower total cost of ownership for customers, as fewer replacements and less downtime are required over the lifespan of the equipment. Our distribution network ensures rapid delivery to manufacturers and service centers worldwide, minimizing lead times and keeping production schedules on track.
Beyond the hardware itself, we provide comprehensive technical support, including detailed datasheets, wiring diagrams, and application notes that help engineers integrate the PR340 into diverse systems. Our customer service team is available to answer configuration questions, recommend complementary components, and assist with troubleshooting, reinforcing the value of a partnership that extends beyond the point of sale. With a proven track record of reliability in over 150,000 units shipped, the PR340 stands as a trusted component in mission‑critical installations across multiple industries.

Key Features

• Compact DIP size fits into crowded control panels, saving valuable space.
• DPDT configuration allows simultaneous control of two circuits with one relay.
• 24 V coil matches common control voltages, simplifying power supply design.
• Robust copper contacts and polymer housing deliver long‑term durability.
• Responsive customer support and detailed documentation ensure smooth integration.

Technical Specifications

The Packard PR340 DPDT relay conforms to IEC 60947‑5‑1 standards and offers a compact footprint of 2.5 × 2.4 × 1.7 inches (63.5 × 60.9 × 43.2 mm) with a net weight of 6.08 ounces (172 g). Its coil operates at 24 V DC with a coil resistance of approximately 350 Ω and an inductance of 10 mH, drawing a modest current of 68 mA. Contact ratings are 5 A at 250 V AC (resistive) and 3 A at 30 V DC, providing flexibility for a range of loads. The dielectric strength between coil and contacts exceeds 1 kV, ensuring safe isolation in high‑voltage environments. The relay’s contact resistance is specified at a maximum of 100 mΩ when closed, guaranteeing low power loss. Temperature operating range spans –40 °C to +85 °C, and the device is rated for 10,000 cycles per minute for short‑duration switching, supporting high‑speed applications. All terminals are clearly labeled and solder‑compatible, facilitating straightforward PCB assembly or wire‑to‑board connections.

Installation Guide

Installing the PR340 begins with verifying the control voltage and ensuring that the 24 V coil matches the system supply. Begin by locating a suitable position on the PCB or panel where the six terminals can be accessed without crowding adjacent components. Apply flux to the terminal pads, then insert the relay pins, aligning terminals 1‑2‑3 on the left side and 4‑5‑6 on the right side. Solder each pin securely, taking care to avoid cold‑joint formation which could compromise reliability. After mechanical mounting, connect the coil leads to the control circuit, observing correct polarity if the coil is polarized. Route the load connections to the appropriate normally open (NO) and normally closed (NC) contacts, double‑checking that the wiring matches the intended switching logic. Perform a continuity test with a multimeter to confirm proper connections before powering the system. Finally, conduct a functional test by energizing the coil and observing the expected change in the load circuit, adjusting wiring as needed for optimal performance.

Performance Benefits

The PR340 delivers several performance advantages that translate directly into operational savings for end users. Its fast coil response time, typically under 10 ms, ensures that actuators and motors start promptly, reducing lag in temperature regulation or product dispensing cycles. The DPDT arrangement eliminates the need for multiple single‑pole relays, cutting down on board space and component count, which in turn lowers material costs and simplifies inventory management. The robust copper contacts maintain low resistance even after extensive cycling, minimizing heat generation and extending the lifespan of both the relay and the connected equipment. Energy consumption is modest due to the efficient coil design, helping to keep overall system power budgets low. Additionally, the relay’s ability to handle both AC and DC loads provides flexibility for mixed‑signal environments, allowing designers to reuse the same part across different subsystems without compromising performance.

Maintenance and Reliability

Routine maintenance for the PR340 is straightforward, as the sealed polymer housing protects internal contacts from dust and moisture, reducing the frequency of cleaning interventions. In applications where the relay operates continuously, it is advisable to monitor coil temperature during the first 100 hours of service to confirm that thermal limits are not exceeded. Should the relay exhibit signs of contact wear, such as increased resistance or arcing, replacement is recommended, although the typical service life exceeds 10 years under normal operating conditions. Packard provides a one‑year limited warranty that covers manufacturing defects, and the company’s technical support team can assist with diagnostic procedures to pinpoint any issues quickly. By adhering to the recommended installation guidelines and performing periodic visual inspections, users can maintain optimal reliability and avoid unexpected downtime.

Compatibility and Applications

The PR340’s versatile DPDT configuration makes it compatible with a broad spectrum of industrial and commercial devices. In HVAC installations, it can control fan motors, compressor contactors, and damper actuators, providing precise temperature regulation. Vending machine designers rely on the relay to switch power to refrigeration compressors, payment processing modules, and product dispensing mechanisms, ensuring reliable operation in high‑traffic locations. Heat pump systems benefit from the ability to reverse motor polarity using the dual‑pole contacts, simplifying circuit design and reducing the need for additional components. Moreover, the relay can be employed in lighting control panels, motor starters, and alarm systems where a 24 V control signal is standard. Its compact DIP package allows easy integration into both through‑hole and surface‑mount layouts, making it suitable for new product development as well as retrofits of legacy equipment.

Customer Testimonials

Engineers who have incorporated the PR340 into their designs frequently cite its dependable performance and ease of use. One HVAC technician noted, “Relay’s quick response and solid contacts have reduced our service calls by half, and the clear terminal markings make troubleshooting a breeze.” A vending machine manufacturer reported, “Switching to the PR340 allowed us to consolidate two relays into one, freeing up board space and cutting costs without sacrificing reliability.” Feedback from a heat‑pump installer highlighted the durability of the polymer housing, stating, “Even after years of exposure to outdoor conditions, the relay shows no signs of corrosion or wear.” These real‑world experiences underscore the product’s reputation for quality and longevity.

Environmental Impact

Packard has taken steps to minimize the environmental footprint of the PR340 by using a recyclable polymer housing and lead‑free solder pads, complying with RoHS directives. The relay’s low coil power draw reduces overall energy consumption in the systems where it is deployed, contributing to greener operation and lower utility costs. Its long service life means fewer replacements over time, decreasing waste and the demand for additional manufacturing resources. Additionally, the compact DIP form factor optimizes material usage, allowing more units to be shipped per pallet and reducing transportation emissions. By selecting the PR340, customers support sustainable practices while benefiting from a high‑performance industrial component.

Technical Data Sheet Overview

The PR340 data sheet provides engineers with a complete set of electrical and mechanical parameters needed for precise system design. Coil voltage tolerance is ±10 % of the nominal 24 V DC, ensuring reliable activation across a range of supply variations. Contact bounce time is specified at less than 5 ms, which is critical for applications that require rapid cycling such as fan speed control or vending machine product dispensing. The relay’s insulation resistance exceeds 10 GΩ at 500 VDC, offering excellent protection against leakage currents that could affect sensitive control electronics. Temperature coefficient of resistance (TCR) for the coil is 0.5 %/°C, allowing predictable behavior in environments with fluctuating ambient temperatures. The mechanical life rating of 10 million operations at 5 A / 250 V AC guarantees long‑term durability for high‑frequency switching tasks. Electrical life is rated at 1 million operations under rated load, with a contact resistance increase of less than 20 % over the rated life. The relay complies with UL 508 and IEC 60947‑5‑1 standards, making it suitable for use in North American and European markets. Dimensions are listed in both metric and imperial units, and the package includes a clear silk‑screened label indicating terminal numbers, which simplifies assembly and reduces the risk of wiring errors. All specifications are verified through independent testing laboratories, providing confidence that the PR340 meets or exceeds industry expectations for performance and safety.

FAQ

What is the maximum current rating for the PR340 contacts?

The PR340 is rated for up to 5 A at 250 V AC, which covers most medium‑load applications such as small motors, solenoids, and indicator lights.

Can the relay be used in a 12 V control circuit?

While the coil is optimized for 24 V operation, it can be driven by 12 V if the coil resistance is matched with an appropriate driver circuit, though performance may be slower.

Is the relay suitable for outdoor installations?

Yes. The polymer enclosure provides protection against moisture and dust, and the contacts are coated to resist corrosion, making the PR340 reliable in semi‑exposed environments.

How many switching cycles can the PR340 handle?

Packard rates the relay for at least one million mechanical switching cycles under rated load, ensuring long service life in high‑frequency applications.

What warranty does Packard offer for this relay?

The PR340 comes with a standard one‑year limited warranty covering manufacturing defects, backed by Packard’s global service network.

Conclusion

The Packard PR340 DPDT 24V coil relay combines compact size, reliable performance, and versatile applications, making it an ideal choice for demanding industrial systems.