Why Comparison Tables Are Only a Starting Point
In industrial and military power systems, the question comes up again and again:
Can a circuit breaker from one manufacturer be replaced with an “equivalent” breaker from another?
To support this need, manufacturers publish cross-reference tables that map product families and mechanical frames across different suppliers. These tables are useful – but they are often misunderstood.
A cross-reference is a starting point, not a design decision.
Treating it as an automatic replacement guide introduces real engineering risk.
Why Do Cross-Reference Tables Exist?
Cross-reference tables serve legitimate engineering and procurement needs:
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Second source strategies for long-life programs
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Obsolescence management
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Cost reduction initiatives
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Initial alignment between engineering and purchasing
They answer a basic question:
“If I know this breaker family, where does it sit in another manufacturer’s portfolio?”
Used correctly, they provide orientation – not validation.
What Cross-Reference Does Provide
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Identification of comparable product families or frames
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General mechanical size and mounting alignment
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High-level application segmentation
In other words, cross-reference helps you understand the landscape.
What Cross-Reference Does Not Guarantee
This is where most mistakes happen.
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Identical trip curves
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Equivalent inrush current tolerance
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Matching response to short-duration faults
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Stable behavior across temperature, vibration, or altitude
Two breakers in the same mechanical frame can behave very differently under real operating conditions.
Why This Matters in Industrial and Military Systems
In critical systems:
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Nuisance tripping is a failure
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Failure to trip is a hazard
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Small behavioral differences become field issues
This is why hydraulic-magnetic circuit breakers are widely used in demanding applications:
their value lies in predictable, repeatable behavior, not just nameplate ratings.
Cross-reference tables cannot capture system-level behavior.
How to Use Cross-Reference Correctly
A responsible approach looks like this:
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Use cross-reference to identify relevant product families
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Analyze trip curves in detail
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Evaluate inrush current characteristics
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Consider environmental and system conditions
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Validate behavior within the actual power architecture
Cross-reference starts the conversation – it does not end it.
Summary
Cross-reference tables are useful engineering tools, but they are not replacement approvals.
In serious power systems, circuit breaker selection must be driven by system behavior, not tables.