What will you do if a Hospital or Nuclear Power Plant needs an Obsolete Westinghouse Circuit Breaker? 

For applications like these, Contact an Authorized Cutler Hammer Distributor or Eaton directly. They have excellent technical help available but sometimes they do not even know what options are available. Some Circuit Breaker resellers have the answers stored in their heads but can you trust that they say is correct?  If they were selling the obsolete item when it was a current series, it was in their best interest to know the answer and find a solution. If they have a solution, is it to the manufactures specs? Some information on-line may be incorrect or the information only states the newer series but does it interchange. Some replacements available from Cutler Hammer will directly interchange without performing any magic. Some styles may need adapters to correct the height to match the buss bar; some may need adapters so the throw of the handle will match a handle mechanism. From our experience with Circuit Breakers since 1985 we know what options you may have.
These following obsolete industrial circuit breakers have replacements types that will directly interchange. A Licienced and Bonded electrical contractor can verify if it will pass code.

The Following series types, EB, EHB, FB, HFB, JB, KB, HKB, LAB, LA, HLA, LC, HLC, MA, HMA have interchangeable replacements available  If you need Types
DK, JA, KA, HKA, MCP you will need adapters to install them properly and are available from the manufacture
There may be some exceptions but for the most part, the information here is correct.

I am not an electrician or electrical engineer and always suggest using a licensed and bonded electrical contractor but I would be happy to share some knowledge, spec sheets and dimension sheets with you if you need them. You can hear a little about us at  https://jrlelectricsupplyinc.com/about-us/