Littelfuse ERDM427 The ERDM Series is a combination of digital electronics and a reliable electromechanical…

Name: Littelfuse ERDM427 delay-on-make relay with DPDT output for OEM timing control.
Brand: Littelfuse
SKU: ERDM427
Availability: InStock

Alternate Item Number: ERDM427

UPC: 079458992991

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Brochure Specification Sheet

Contact for Pricing

Call +1 (262) 252-1600 (toll-free 877-268-3700) or email [email protected] for pricing and availability.

Overview

The Littelfuse ERDM427 is a cost-effective delay-on-make relay combining digital electronics with a reliable electromechanical DPDT relay for precise timing control in OEM applications. Engineered for industrial automation, HVAC systems, and machinery control, this relay provides isolated 10A DPDT output contacts rated for 120/240VAC and 28VDC, supporting loads up to 1/3 hp. The device features a fixed 0.1–5 minute delay range with ±0.5% repeat accuracy and ±10% factory calibration tolerance, ensuring consistent performance across operating conditions. Input voltage options include 120VAC, with environmental robustness spanning -40°C to 65°C operation and -40°C to 85°C storage. The ERDM427 starts timing upon input voltage application, keeping the output de-energized during the delay before energizing and remaining active until input removal. Its encapsulated design protects against shock, vibration, and humidity, while surface-mount installation with two #6 screws simplifies integration. Ideal for applications such as random starting, sequencing ON, switch de-bouncing, and anti-short cycling, this relay eliminates the need for external timing modules or complex programming. The 43.2mm (1.7") depth, 88.9mm (3.5") height, and 63.5mm (2.5") width make it compact for control panels, and the 0.25in (6.35mm) male quick-connect terminals enable easy wiring. With a mechanical life of 10 million operations and full-load life of 1 million operations, the ERDM427 delivers long-term reliability in demanding industrial environments.

DPDT relay output with 10A @ 120/240VAC & 28VDC; 1/3 hp @ 120/240VAC
Fixed 0.1–5 minute delay range with ±0.5% repeat accuracy
Isolated input-to-output voltage for safe relay logic circuit control
Surface-mount design with 43.2mm D x 88.9mm H x 63.5mm W dimensions
Operating temperature: -40°C to 65°C; storage: -40°C to 85°C

Specifications

Brand Name	Littelfuse
Mounting	Surface mount with four #6 (M3.5 x 0.6) screws Mount
Mounting	Surface mount with four #6 (M3.5 x 0.6) screws
Number Of Poles	Surface mount with four #6 (M3.5 x 0.6) screws
Operating Temperature	-40 to 65 F
Operating Temperature, Maximum	65 F
Operating Temperature, Minimum	-40 F
Poles	DPDT
Series	ERDM
Series	ERDM Series
Special Features	10Y WARR
Standard	CE/UR/CSA
Sub Brand	SSAC

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THDB421A

The THDB Series combines accurate timing circuitry with high power, solid-state switching. It can switch motors, lamps, and heaters directly without a contactor. You can reduce labor, component cost, and increase reliability with these small, easy-to-use, THDB Series timers. Operation (Delay-on-Break): Input voltage must be applied before and during timing. Upon closure of the initiate switch, the output energizes. The time delay begins when the initiate switch is opened. The output remains energized during timing. At the end of the time delay, the output de-energizes. The output energizes if the initiate switch is closed when input voltage is applied. Reset: Reclosing the initiate switch during timing resets the time delay. Loss of input voltage resets the time delay and output.

RS4A22

The RS Series is a solid-state, encapsulated, recycling timer designed for tough industrial environments. It is used by many testing labs as a life cycle tester; by others as a cycle controller. The RS Series has separate DIP switch adjustments for the on delay and the off delay. These make accurate adjustment possible the first time, every time. Time delays of 0.1 seconds to 1023 hours are available in 4 ranges. Operation (Recycling - ON Time First): Upon application of input voltage, the output energizes and the T1 ON time begins. At the end of the ON time, the output de-energizes and the T2 OFF time begins. At the end of theOFF time, the output energizes and the cycle repeats as long as input voltage is applied. Reset: Removing input voltage resets the output and time delays, and returns the sequence to the ON time. Operation (Recycling - OFF Time First): Upon application of input voltage, the T2 OFF time begins. At the end of the OFF time, the output energizes and the T1 ON time begins. At the end of the ON time, the output de-energizes and the cycle repeats as long as input voltage is applied. Reset: Removing input voltage resets the output and time delays, and returns the sequence to the OFF time.

Frequently Asked Questions

What is the output rating of the ERDM427 relay?

The output is rated 10A resistive at 120/240VAC and 28VDC, with a maximum load of 1/3 hp at 120/240VAC.

What are the dimensions of the ERDM427?

The ERDM427 measures 43.2mm (1.7") depth, 88.9mm (3.5") height, and 63.5mm (2.5") width.

What environmental conditions can the ERDM427 operate in?

The device operates from -40°C to 65°C and stores from -40°C to 85°C.

What input voltages does the ERDM427 support?

The ERDM427 supports 120VAC input voltage with a tolerance of -20% to +10%.

What is the reset behavior of the ERDM427?

Removing input voltage resets the time delay and output, de-energizing the relay.

How is the time delay adjusted on the ERDM427?

The ERDM427 features a fixed time delay range of 0.1 to 5 minutes with onboard adjustment via a knob.

What is the mechanical life of the ERDM427 relay?

The mechanical life is rated at 10 million operations, with a full-load life of 1 million operations.

What is the isolation voltage rating of the ERDM427?

The relay provides isolation voltage of ≥1500V RMS between input and output.

Frequently Asked Questions about Littelfuse

What certifications and standards do Littelfuse products comply with?

Littelfuse products are certified to multiple international standards, including UL (Underwriters Laboratories), CSA (Canadian Standards Association), CCC (China Compulsory Certification), and EAC (Eurasian Conformity). Customers can verify specific product certifications by consulting individual product datasheets on Littelfuse.com, which provide comprehensive details about standards compliance for each component.

What industries and applications are Littelfuse products used for?

Littelfuse products are critical for electrical protection and safety across multiple industrial sectors, including manufacturing, automation, power distribution, and electrical control systems. Their comprehensive product portfolio serves industries that require robust electrical protection, including motor and pump applications, solar installations, programmable logic controllers (PLCs), electrical switch panels, and critical infrastructure environments. Key product lines protect against overcurrent, voltage transients, ground faults, and temperature-related electrical risks, ensuring equipment safety and operational reliability.

What technical support does Littelfuse offer?

Littelfuse offers comprehensive technical support through multiple channels. Their Technical Hotline (800-TEC-FUSE) provides direct access to engineers who can help identify issues and recommend solutions. Additionally, Littelfuse offers extensive online Technical Resources at Littelfuse.com, including datasheets, product manuals, whitepapers, application guides, and online design tools. Their experienced product and application engineers also provide step-by-step support from design to installation.

What are the main product lines offered by Littelfuse?

Littelfuse offers comprehensive industrial protection and control product lines, including fuses, fuse holders, protection relays, temperature sensors, and electrical safety components. Their key product categories span surge protective devices, custom OEM products, electrical switch panels, medium voltage fuses, ground-fault protection relays, motor and pump protection devices, and temperature sensors. These products are designed to minimize electrical safety hazards, limit equipment damage, improve productivity, and safeguard personnel from electrical faults.

What are the key features of Littelfuse products?

Littelfuse products feature exceptional circuit protection technologies with key characteristics including UL/IEC safety standard compliance, low internal resistance, and advanced protective capabilities across multiple product lines. Their components provide critical protection for industrial systems, offering features like overcurrent protection, voltage transient suppression, and resettable protection devices with ultra-low resistance and compact designs. Key product lines include fuses, metal oxide varistors (MOVs), TVS diodes, PolySwitch devices, and specialized electronic protection components that enhance system reliability and safety.

What environmental ratings do Littelfuse products have?

Littelfuse products feature comprehensive environmental ratings, including NEMA Type 1, 2, 3, 3R, 4/4X, 12, and 13 certifications, as well as IP65 protection. These ratings ensure superior protection in diverse industrial environments, with an operating temperature range of -40°F to +131°F (-40°C to +55°C). Many products also include UV-stabilized materials and neoprene gaskets for enhanced durability in outdoor and challenging conditions.

What accessories are available for Littelfuse products?

Littelfuse offers several key accessories across their product lines, including fuse holders, voltage monitoring modules, and terminal connectors. Specific accessories include the LPSM003ZXID (indicating) and LPSM003Z (non-indicating) POWR-SAFE Dead Front fuse holders for Class CC and Midget-Style fuses, the VRM6048 voltage monitor accessory module, and female quick connect terminals (P1015 series) in various wire gauge sizes. These accessories are designed to enhance protection, monitoring, and connectivity for Littelfuse electrical components.

What is Littelfuse's warranty policy?

Littelfuse provides comprehensive warranty details on their official website at www.littelfuse.com/warranty. Customers should visit this page to review the specific warranty terms and conditions for their specific product lines. For direct warranty support or questions, customers can contact Littelfuse Technical Support at 1-800-TEC-FUSE or email [email protected].

What communication protocols do Littelfuse products support?

Littelfuse supports a comprehensive range of industrial communication protocols, including PROFIBUS, PROFINET, EtherNet/IP, DeviceNet, Modbus RTU, and CANopen. Our products provide flexible connectivity solutions across multiple industrial automation platforms, enabling seamless integration with various control systems and network architectures.

How are Littelfuse products typically installed?

Littelfuse products are typically installed using specialized mounting hardware like fuse holders, blocks, and panels designed for specific industrial applications. The POWR-SAFE Dead Front holders, for example, provide optimum protection for Class CC and Midget-Style fuses, supporting installations up to 600 VAC/DC. Installation often involves using precision terminals with strain relief, such as 0.25 in. female quick connect terminals, to ensure secure and safe electrical connections in industrial control systems.