HC4-H-AC12V General Purpose Relay 4PDT 12VAC Equivalent & Substitute Parts

Part Overview

The Panasonic Electric Works HC4-H-AC12V is a general purpose relay with 4PDT (4 Form C) contact configuration, rated for 5A at 12VAC coil voltage. This socketable relay is classified as obsolete, making equivalent and substitute parts necessary for ongoing system maintenance and new design implementations. The part operates across a temperature range of -50°C to 70°C with 20ms operate and release times, utilizing silver nickel contact material for general switching applications up to 250VAC.

Key Parameters

Parameter	HC4-H-AC12V
Manufacturer	Panasonic Electric Works
Coil Voltage	12VAC
Contact Form	4PDT (4 Form C)
Contact Rating (Current)	5A
Switching Voltage (Max)	250VAC
Coil Current	100 mA
Mounting Type	Socketable
Termination Style	Plug In
Operating Temperature Range	-50°C to 70°C
Product Status	Obsolete

Substitute Part Grouping Explanation

Substitution eligibility for the HC4-H-AC12V is determined by the following critical parameters:

Coil Voltage: Must be 12VAC
Contact Form: Must be 4PDT (4 Form C)
Mounting Type: Must be Socketable with Plug In termination
Coil Type: Must be Non Latching
Contact Rating (Current): 5A minimum required for direct replacement; higher ratings acceptable
Switching Voltage: 240VAC or higher acceptable; 250VAC minimum preferred
Coil Current: 100 mA nominal; variations within 70 mA to 170 mA acceptable for socketable designs

Substitute parts are grouped into two categories:

Category 1 - Direct Equivalents (5A Rating): KHAU-17A12-12 and KHAU-17A12B-12 from TE Connectivity Potter & Brumfield Relays maintain identical 5A contact ratings with socketable configuration and 12VAC coil specification.

Category 2 - Functional Alternatives (Reduced Current Rating): KHU-17A11-12 provides 3A contact rating with identical form factor and coil specification, suitable for applications not requiring full 5A capacity.

Category 3 - Enhanced Performance Alternative (Increased Current Rating): LY4-AC12 from Omron Automation and Safety provides 10A contact rating with socketable configuration and 12VAC coil, suitable for higher current switching requirements.

Parameter Comparison

Parameter	HC4-H-AC12V	KHAU-17A12-12	KHAU-17A12B-12	KHU-17A11-12	LY4-AC12
Manufacturer	Panasonic	TE Connectivity	TE Connectivity	TE Connectivity	Omron
Coil Voltage	12VAC	12VAC	12VAC	12VAC	12VAC
Contact Form	4PDT	4PDT	4PDT	4PDT	4PDT
Contact Rating (Current)	5A	5A	5A	3A	10A
Switching Voltage (Max)	250VAC	240VAC	240VAC	240VAC	250VAC, 125VDC
Coil Current	100 mA	100 mA	100 mA	100 mA	170 mA
Mounting Type	Socketable	Socketable	Socketable	Socketable	Socketable
Termination Style	Plug In	Plug In	Plug In	Plug In	Plug In
Operate Time	20 ms	13 ms	13 ms	13 ms	25 ms
Release Time	20 ms	6 ms	6 ms	6 ms	25 ms
Operating Temperature Range	-50°C to 70°C	-45°C to 70°C	-45°C to 70°C	-45°C to 70°C	-25°C to 40°C
Product Status	Obsolete	Active	Active	Active	Active
RoHS Status	Not specified	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	RoHS Compliant

Engineering Selection Recommendations

For Direct Replacement (Identical Current Rating)

KHAU-17A12-12 and KHAU-17A12B-12 are active products from TE Connectivity Potter & Brumfield Relays series, both ROHS3 compliant. These parts maintain the 5A contact rating and 12VAC coil specification of the HC4-H-AC12V. KHAU-17A12B-12 includes a test button feature. Both operate with faster switching times (13ms operate, 6ms release) compared to the original part. Operating temperature range is -45°C to 70°C, which covers most industrial applications, though the lower minimum temperature (-45°C vs -50°C) should be evaluated for extreme cold environments.

For Reduced Current Applications

KHU-17A11-12 from TE Connectivity Potter & Brumfield Relays series is ROHS3 compliant and suitable for applications requiring only 3A contact rating. This part maintains socketable configuration and 12VAC coil specification with identical switching characteristics to the KHAU series.

For Increased Current Capacity

LY4-AC12 from Omron Automation and Safety provides 10A contact rating for applications requiring higher current switching capacity. This part is RoHS compliant and maintains socketable configuration with 12VAC coil. The operating temperature range is -25°C to 40°C, which is narrower than the original part and should be evaluated for applications requiring extended temperature operation.

All substitute parts maintain the socketable mounting type and plug-in termination style required for direct socket compatibility.

Frequently Asked Questions (FAQ)

Q: Can KHAU-17A12-12 directly replace HC4-H-AC12V in existing sockets?

A: Yes. Both parts are socketable with plug-in termination and maintain identical 12VAC coil voltage, 4PDT contact form, and 5A contact rating. Pin configuration compatibility should be verified against the socket specification.

Q: What is the difference between KHAU-17A12-12 and KHAU-17A12B-12?

A: KHAU-17A12B-12 includes a test button feature. Both parts are electrically identical with 5A contact rating, 12VAC coil, and 4PDT configuration. Selection depends on whether manual test capability is required in the application.

Q: Can KHU-17A11-12 be used where HC4-H-AC12V is specified?

A: KHU-17A11-12 is suitable only for applications where the maximum contact current requirement does not exceed 3A. The part maintains 12VAC coil voltage, 4PDT configuration, and socketable mounting. Applications requiring the full 5A rating must use KHAU-17A12-12 or KHAU-17A12B-12.

Q: Is LY4-AC12 compatible with HC4-H-AC12V sockets?

A: LY4-AC12 maintains socketable configuration and plug-in termination with 12VAC coil and 4PDT contact form. However, the 10A contact rating and different coil current (170 mA vs 100 mA) require verification of socket and circuit compatibility. The narrower operating temperature range (-25°C to 40°C) must be evaluated against application requirements.

Q: What compliance certifications apply to substitute parts?

A: KHAU-17A12-12, KHAU-17A12B-12, and KHU-17A11-12 are ROHS3 compliant. LY4-AC12 is RoHS compliant. All parts carry EAR99 ECCN classification.

Q: How do switching times differ between the original and substitute parts?

A: HC4-H-AC12V operates with 20ms operate and 20ms release times. KHAU-17A12-12, KHAU-17A12B-12, and KHU-17A11-12 operate with 13ms operate and 6ms release times, providing faster switching response. LY4-AC12 operates with 25ms operate and 25ms release times, which is slower than the original part.

Q: Are there temperature range limitations with substitute parts?

A: HC4-H-AC12V operates from -50°C to 70°C. TE Connectivity parts (KHAU and KHU series) operate from -45°C to 70°C, suitable for most industrial applications but with a 5°C higher minimum temperature limit. LY4-AC12 operates from -25°C to 40°C, which is significantly narrower and unsuitable for extended temperature applications.

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