ALZ21B09 General Purpose Relay SPST 16A 9VDC Equivalent & Substitute Parts

Part Overview

The ALZ21B09 is a general purpose relay manufactured by Panasonic Electric Works, configured as a single-pole single-throw normally open (SPST-NO) contact form with a 9VDC coil. This through-hole mounted relay is rated for 16A switching current at 440VAC maximum and features sealed flux protection with silver tin oxide contacts. The ALZ21B09 is currently obsolete, making equivalent and substitute parts necessary for ongoing system maintenance and new design implementations where this relay specification is required.

Substiute Parts

ALZ21B09

Panasonic Electric WorksIn Stock: 702ALZ21B09 Datasheet

Current PartRFQ

ALZ51B09

Panasonic Electric WorksIn Stock: 1166ALZ51B09 Datasheet

DirectRFQ

ALZ51B09T

Panasonic Electric WorksIn Stock: 982ALZ51B09T Datasheet

Parametric EquivalentRFQ

1-1415540-6

TE Connectivity Potter & Brumfield RelaysIn Stock: 12271-1415540-6 Datasheet

SimilarRFQ

RZ03-1A4-D009

TE Connectivity Potter & Brumfield RelaysIn Stock: 2193RZ03-1A4-D009 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the ALZ21B09 is determined by strict equivalence across the following critical parameters: coil voltage (9VDC), contact form (SPST-NO), contact current rating (16A minimum), switching voltage capability (440VAC or higher), mounting type (through hole), and termination style (PC pin). Parts are grouped into two categories:

Direct Manufacturer Equivalents maintain identical electrical specifications and contact material composition, differing only in product status or packaging format.

Parametric Equivalents satisfy all functional requirements but may vary in secondary characteristics such as coil insulation class, contact material, or timing specifications, provided these variations remain within acceptable operating parameters for the application.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Active Product Status):

ALZ51B09 and ALZ51B09T are the primary substitutes for the obsolete ALZ21B09. Both are manufactured by Panasonic Electric Works and maintain identical electrical and mechanical specifications. ALZ51B09T carries RoHS compliance certification, making it suitable for applications with environmental regulatory requirements. Both parts are currently in active production with confirmed inventory availability.

For Cross-Manufacturer Substitution:

RZ03-1A4-D009 manufactured by TE Connectivity Potter & Brumfield Relays is an active product that satisfies all functional requirements. This part operates with identical coil voltage, contact form, and current rating. The switching voltage specification of 400VAC is lower than the ALZ21B09 maximum of 440VAC; applications operating above 400VAC require verification that the lower rating is acceptable. RZ03-1A4-D009 features Class F coil insulation versus Class B in the original part, providing enhanced thermal performance. Timing characteristics differ slightly (8ms operate, 6ms release versus 15ms/5ms), which may affect circuit behavior in time-sensitive applications.

1-1415540-6 is obsolete and not recommended for new designs despite meeting core electrical specifications. This part is retained in the substitute list for legacy system maintenance only.

Frequently Asked Questions (FAQ)

Q: Can ALZ51B09 directly replace ALZ21B09 in existing designs?

A: Yes. ALZ51B09 maintains identical coil voltage (9VDC), contact form (SPST-NO), current rating (16A), switching voltage (440VAC), mounting type (through hole), and termination style (PC pin). The parts are electrically and mechanically interchangeable. ALZ51B09 is the recommended direct replacement due to active product status and availability.

Q: What is the difference between ALZ51B09 and ALZ51B09T?

A: Both parts are electrically identical. ALZ51B09T carries explicit RoHS compliance certification, while ALZ51B09 does not specify RoHS status. For applications requiring RoHS compliance documentation, ALZ51B09T is the appropriate selection.

Q: Can RZ03-1A4-D009 replace ALZ21B09?

A: RZ03-1A4-D009 satisfies the core functional requirements of 9VDC coil, SPST-NO contact form, 16A rating, and through-hole mounting. However, the switching voltage maximum is 400VAC compared to 440VAC for the original part. Applications operating between 400VAC and 440VAC require circuit analysis to confirm acceptability. Additionally, operate time is 8ms versus 15ms in the original; timing-critical circuits must be evaluated. RZ03-1A4-D009 is suitable for applications where these parameter variations are acceptable.

Q: Why do some substitutes have different contact materials?

A: ALZ21B09, ALZ51B09, and ALZ51B09T use silver tin oxide (AgSnO) contacts. RZ03-1A4-D009 and 1-1415540-6 use silver nickel (AgNi) contacts. Both materials are suitable for general purpose relay applications at the specified current and voltage ratings. Contact material selection does not affect substitution eligibility for this product category.

Q: What is the significance of coil insulation class differences?

A: ALZ21B09 uses Class B insulation; RZ03-1A4-D009 uses Class F. Class F provides higher thermal capability. This difference does not prevent substitution but indicates that RZ03-1A4-D009 may operate at higher ambient temperatures or with greater coil power dissipation. For standard operating conditions within -40°C to 85°C, both insulation classes are functionally equivalent.

Q: Are there inventory considerations for part selection?

A: ALZ51B09 (1070 pcs), ALZ51B09T (897 pcs), and RZ03-1A4-D009 (2114 pcs) all have confirmed stock availability. ALZ21B09 (635 pcs) remains available as original stock but is obsolete. For new procurements, ALZ51B09 or ALZ51B09T are recommended to ensure long-term supply continuity.