Seems that Hammond designs their Europe (with "E" designation) Transformers at 240
Gemini says this:
"The core reason why Hammond designs transformers for Europe at 240V rather than 220V is due to the process of voltage standardization and harmonization within Europe.
Here's a breakdown:
Historical variations: Historically, different European countries used different mains voltage standards, including 220V in much of continental Europe and 240V in the UK.
Harmonization to 230V: The European standard now defines the nominal voltage as 230V.
Tolerance: This 230V standard allows for a tolerance range. In most of Europe (formerly 220V countries), the tolerance is 230V -10% +6% (207V to 243.8V). In the UK (formerly 240V countries), the tolerance is 230V -6% +10% (216.2V to 253.0V).
Practically, 240V is still within the acceptable range: Since 240V falls within the permissible +10% tolerance band of the 230V standard in the UK, and generally within the wider tolerance range in other parts of Europe, transformers designed for 240V are perfectly compatible with the modern European standard.
Compatibility: This allows manufacturers like Hammond to produce transformers that work across the harmonized European market, simplifying design and manufacturing.
In essence, by designing for 240V, Hammond creates a product that meets the current European standard (230V ± tolerance) and is compatible with the historically established 240V grids, particularly in the UK."