AZ851-3 General Purpose Relay DPDT 1A 3V - Equivalent & Substitute Parts

Part Overview

The AZ851-3 is a general purpose relay manufactured by American Zettler, featuring a DPDT (2 Form C) contact configuration with 1A contact rating and 3VDC coil voltage. This surface mount relay is designed for general switching applications requiring sealed, fully enclosed construction. The part is currently active in production with 735 pieces in stock.

Substitute parts are identified when equivalent electrical and mechanical parameters allow direct functional replacement in the same application circuit. Substitution eligibility is determined by matching critical parameters including coil voltage, contact form, coil current, operating voltage thresholds, and termination style.

Substiute Parts

AZ851-3

American ZettlerIn Stock: 841AZ851-3 Datasheet

Current PartRFQ

TQ2SA-3V

Panasonic Electric WorksIn Stock: 1890TQ2SA-3V Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

The TQ2SA-3V from Panasonic Electric Works qualifies as a substitute part based on the following matching parameters:

Critical Matching Parameters:

• Coil Voltage: 3VDC (identical)
• Contact Form: DPDT (2 Form C) (identical)
• Coil Current: 46.7 mA (identical)
• Mounting Type: Surface Mount (identical)
• Termination Style: Gull Wing (identical)
• Must Operate Voltage: 2.25 VDC (identical)
• Must Release Voltage: 0.3 VDC (identical)
• Operating Temperature Range: -40°C ~ 85°C (identical)
• Coil Resistance: 64.3 Ohms (identical)
• RoHS Status: ROHS3 Compliant (identical)

Allowable Parameter Differences:

• Contact Rating: TQ2SA-3V rated at 2A versus AZ851-3 at 1A (higher rating acceptable for substitution)
• Switching Voltage: TQ2SA-3V rated 125VAC/220VDC versus AZ851-3 at 250VAC/220VDC (application-dependent)
• Operate/Release Time: TQ2SA-3V at 4ms each versus AZ851-3 at 2ms/1ms (timing-dependent applications)
• Contact Material: TQ2SA-3V uses AgNi/Au versus AZ851-3 uses AgPd/Au (both acceptable for general switching)

Parameter Comparison

Engineering Selection Recommendations

AZ851-3 Selection Criteria:

• Primary choice when 1A contact rating is specified and sufficient for the application
• Required when 250VAC switching voltage is necessary
• Preferred when faster switching response is critical (2ms operate, 1ms release)
• Active product status with established supply chain (735 pieces in stock)
• ROHS3 compliant for regulated markets

TQ2SA-3V Selection Criteria:

• Suitable when higher contact current capacity (2A) provides design margin
• Acceptable for applications not requiring 250VAC switching capability
• Applicable when slightly longer switching times (4ms operate/release) are tolerable
• Active product status with larger inventory availability (1800 pieces in stock)
• ROHS3 compliant; additional REACH and ECCN documentation available
• Telecom relay classification indicates suitability for telecommunications applications

Substitution Constraints:

• Do not substitute AZ851-3 with TQ2SA-3V in circuits requiring 250VAC switching voltage
• Do not substitute in time-critical applications where 2ms/1ms switching response is mandatory
• Verify contact material compatibility (AgPd versus AgNi) with specific load characteristics in the application

Frequently Asked Questions (FAQ)

Q: Can TQ2SA-3V directly replace AZ851-3 in all applications?

A: No. Substitution is valid only when the application does not require 250VAC switching voltage capability and can tolerate 4ms switching times instead of 2ms/1ms. Both parts share identical coil voltage (3VDC), contact form (DPDT), coil current (46.7mA), and operating voltage thresholds (2.25VDC operate, 0.3VDC release).

Q: What is the significance of the higher 2A contact rating on TQ2SA-3V?

A: The TQ2SA-3V 2A rating is higher than the AZ851-3 1A rating. This allows the Panasonic part to handle greater switching currents. For applications designed for 1A operation, the TQ2SA-3V provides additional current capacity margin but does not reduce performance in lower-current circuits.

Q: Are the contact materials interchangeable?

A: Both parts use gold-plated contacts. The AZ851-3 uses Silver Palladium (AgPd) base material while TQ2SA-3V uses Silver Nickel (AgNi) base material. Both are acceptable for general switching applications. Contact material selection depends on specific load type and switching frequency in the application circuit.

Q: What are the packaging differences?

A: AZ851-3 is supplied in Box packaging while TQ2SA-3V is supplied in Tube packaging. Both are surface mount with Gull Wing termination style, compatible with standard SMT assembly processes.

Q: Which part should be selected for new designs?

A: For new designs, either part is acceptable based on application requirements. If 250VAC switching is required, AZ851-3 is mandatory. If faster switching response (2ms/1ms) is critical, AZ851-3 is required. For general 3VDC DPDT switching applications without these constraints, TQ2SA-3V offers higher current capacity and larger inventory availability.

Q: Are both parts RoHS compliant?

A: Yes. Both AZ851-3 and TQ2SA-3V are ROHS3 compliant. TQ2SA-3V additionally carries REACH Unaffected status and ECCN EAR99 classification for export control purposes.