SG42 Inrush Current Limiter - Equivalent & Substitute Parts

Part Overview

The SG42 is an inrush current limiter manufactured by Ametherm, part of the SURGE-GARD™ series. This component is designed to limit inrush current in electrical circuits, with a nominal resistance of 10 Ohms at ±15% tolerance and a maximum steady-state current rating of 5 A. The part is currently in active production status with 1301 units in stock. The SG42 is ROHS3 compliant and carries CSA and UR approvals, making it suitable for regulated applications. Substitute parts are identified when equivalent electrical performance and mechanical compatibility can be maintained within the specified parameter ranges for this product category.

Substiute Parts

SG42

AmethermIn Stock: 1315SG42 Datasheet

Current PartRFQ

B57238S0100M000

EPCOS - TDK ElectronicsIn Stock: 5557B57238S0100M000 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SG42 is determined by the following critical parameters:

• Electrical Performance: Resistance value of 10 Ohms with tolerance range compatibility
• Current Rating: Maximum steady-state current of 5 A or greater
• Physical Dimensions: Diameter and lead spacing must accommodate existing PCB layouts and mechanical assemblies
• Regulatory Compliance: RoHS3 compliance and recognized approval agencies (UL, CSA, UR)
• Product Status: Active production status ensures availability and supply chain continuity

The B57238S0100M000 qualifies as a substitute based on matching resistance value, current rating, and regulatory compliance. Dimensional variations (diameter 0.630" vs. 0.600" and lead spacing 0.295" vs. 0.310") represent acceptable mechanical tolerances within standard PCB design practices for through-hole component placement.

Parameter Comparison

Engineering Selection Recommendations

Both the SG42 and B57238S0100M000 are active production components with ROHS3 compliance and recognized regulatory approvals. The SG42 carries CSA and UR certifications, while the B57238S0100M000 carries UL certification. All three approval agencies (CSA, UR, UL) are equivalent in scope for electrical safety compliance in industrial and commercial applications.

The primary selection criterion is mechanical fit within the existing PCB layout. The dimensional differences (0.030" diameter variation and 0.015" lead spacing variation) are within standard PCB design tolerances for through-hole components. Inventory availability should also be considered: the SG42 has 1301 units in stock, while the B57238S0100M000 has 5462 units available.

Frequently Asked Questions (FAQ)

Q: Can the B57238S0100M000 be used as a direct replacement for the SG42?

A: Yes, the B57238S0100M000 qualifies as a substitute. Both components share the same 10 Ohm resistance value, 5 A current rating, and ROHS3 compliance. Dimensional variations are within acceptable mechanical tolerances for standard PCB layouts.

Q: What is the impact of the ±20% tolerance on the B57238S0100M000 compared to the ±15% tolerance on the SG42?

A: The B57238S0100M000 has a wider tolerance band (±20% vs. ±15%). In applications where resistance precision is critical, the SG42 provides tighter tolerance control. For general inrush current limiting applications, both tolerance ranges are functionally equivalent.

Q: Are the dimensional differences between these parts significant?

A: The diameter difference (0.030") and lead spacing difference (0.015") are minor variations within standard PCB design practices. Verification of PCB hole positioning and component clearance is recommended during layout review, particularly in space-constrained designs.

Q: Do both parts carry equivalent regulatory approvals?

A: Both components are ROHS3 compliant. The SG42 carries CSA and UR approvals, while the B57238S0100M000 carries UL approval. These certifications are equivalent in scope for electrical safety compliance.

Q: Which part should be selected based on availability?

A: The B57238S0100M000 has higher inventory availability (5462 units vs. 1301 units). For applications requiring immediate procurement or high-volume orders, the B57238S0100M000 may offer supply chain advantages.