The fire resistance rating test standard for oil-immersed transformers only applies to "transformers/reactors containing flammable insulating oil," and not to dry-type transformers.

I. Clarifying the Applicable Product Scope (National/International Standards)

These standards (GB/T 261, GB 2536, NB/T 11307.2, IEC 61936, relevant UL oil-immersed standards)

apply only to the following products:

Oil-immersed distribution transformers

10kV oil-immersed transformers

Pole-mounted oil-immersed transformers (cylindrical type, standard type)

Internal transformers in oil-immersed substations

Oil-immersed power transformers

35kV, 110kV, and other high-voltage oil-immersed transformers

Oil-immersed reactors, oil-immersed instrument transformers

Using mineral oil/ester oil/ Oil-immersed equipment with high flash point insulating oil

II. Inapplicable Products (Very Important)

The following products cannot use the oil-immersed fire protection standard and must use the fire protection standard specifically for dry-type transformers:

Epoxy-cast dry-type transformers

Non-encapsulated dry-type transformers

Dry-type reactors

Dry-type box-type substations

Any oil-free, air-insulated electrical equipment

III. In a very simple summary: The fire protection testing standard for oil-immersed transformers only applies to oil-immersed transformers, reactors, and instrument transformers containing insulating oil; it absolutely does not apply to dry-type transformers.