Honeywell POS287311 Liquid Level Sensor - Equivalent & Substitute Parts

Part Overview

The Honeywell POS287311 is a liquid level sensor with NPN output configuration, designed for bracket mount installation in industrial applications. This sensor features stainless steel housing and prism materials, operating across a temperature range of -25°C to 140°C with a voltage rating of 12 to 28V. The product is classified as obsolete, making identification of functionally equivalent substitute components essential for system maintenance, repair, and new design implementations where legacy compatibility is not required.

Substiute Parts

POS287311

Honeywell Sensing and Productivity SolutionsIn Stock: 964POS287311 Datasheet

Current PartRFQ

SQ4-A21-N

Panasonic Industrial Automation SalesIn Stock: 978SQ4-A21-N Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the Honeywell POS287311 is determined by the following critical parameters that must align between the main part and substitute components:

Primary Substitution Criteria:

• Output Configuration: NPN (electrical interface requirement)
• Sensor Type: Liquid level detection
• Mounting Type: Bracket mount (mechanical interface requirement)
• Voltage Rating: Compatible operating voltage range (12 to 28V for main part; 12 to 24V for substitute)
• Current Rating: 200 mA maximum
• RoHS Compliance: Environmental and regulatory requirement

Secondary Compatibility Factors:

• Operating temperature range (main part: -25°C to 140°C; substitute: -10°C to 55°C)
• Housing material (main part: stainless steel; substitute: polypropylene)
• MSL rating (both rated at 1 - Unlimited)

The substitute part SQ4-A21-N from Panasonic Industrial Automation Sales meets the primary electrical and mechanical substitution criteria. However, differences in operating temperature range and housing material must be evaluated against specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

For Direct Substitution Applications:

The Panasonic SQ4-A21-N serves as a functional substitute for the obsolete Honeywell POS287311 in applications where the following conditions are met:

1. Operating voltage does not exceed 24V (the substitute's maximum rating)
2. Operating temperature range remains within -10°C to 55°C
3. Chemical compatibility with polypropylene housing is acceptable for the liquid medium being sensed
4. Bracket mount mechanical interface is compatible with existing installation points

For Applications Requiring Extended Temperature Range or Stainless Steel Housing:

Alternative substitutes beyond the provided list must be evaluated, as the Panasonic SQ4-A21-N does not fully replicate the Honeywell POS287311's extended temperature capability (-25°C to 140°C) or stainless steel construction.

Compliance Considerations:

Both the main part and substitute are RoHS compliant. The Panasonic SQ4-A21-N carries ROHS3 compliance, representing current regulatory standards. The Honeywell part's RoHS compliance status reflects its design era. Both components carry MSL rating 1 (Unlimited), indicating no moisture sensitivity restrictions during storage or handling.

Frequently Asked Questions (FAQ)

Q: Can the Panasonic SQ4-A21-N directly replace the Honeywell POS287311 in all applications?

A: No. The substitute is compatible only when operating voltage does not exceed 24V and operating temperature remains within -10°C to 55°C. Applications requiring the full -25°C to 140°C range or 28V operation require alternative solutions.

Q: What is the significance of the different housing materials (stainless steel vs. polypropylene)?

A: Housing material affects chemical resistance and durability in specific liquid environments. Stainless steel offers superior corrosion resistance in aggressive chemical applications. Polypropylene is suitable for many aqueous and mild chemical applications but may not be appropriate for all liquid media. Application-specific liquid compatibility must be verified.

Q: Are both parts RoHS compliant?

A: Yes. The Honeywell POS287311 is RoHS Compliant. The Panasonic SQ4-A21-N is ROHS3 Compliant, representing a more recent compliance standard. Both meet environmental regulatory requirements.

Q: What does MSL rating 1 (Unlimited) mean for these components?

A: MSL (Moisture Sensitivity Level) rating 1 indicates the component has unlimited shelf life without special moisture control measures. No desiccant storage or baking procedures are required before installation.

Q: Why is the Honeywell POS287311 listed as obsolete?

A: Obsolete status indicates the manufacturer has discontinued production. The part remains available through existing inventory channels but will not receive design updates or long-term availability guarantees. Substitution planning is recommended for new designs or long-term system support.

Q: How do I verify mechanical compatibility between the bracket mount interfaces?

A: Mechanical compatibility requires comparison of mounting hole patterns, bracket dimensions, and sensor body geometry. This information must be obtained from detailed mechanical drawings provided by each manufacturer. The provided parameters confirm both use bracket mount configuration but do not specify dimensional details.

Q: What current rating should I use for circuit design with the Panasonic SQ4-A21-N?

A: The Honeywell POS287311 is rated for 200 mA maximum current. The Panasonic SQ4-A21-N current rating is not specified in the provided data. Obtain the current specification from Panasonic technical documentation before finalizing circuit design.