Final answer:
The statement that dry-type transformers rated over 35KV shall be installed in a vault is false. Dry type transformers rated over 35KV installed indoors are generally not placed in a vault due to the need for proper ventilation and cooling. The statement is false.
Step-by-step explanation:
Dry-type transformers rated over 35 kV installed indoors are typically not placed in a vault. Instead, they are usually installed in enclosures that provide for proper ventilation and cooling. These transformers are designed to be installed in open spaces to allow for adequate dissipation of heat.
This is because dry-type transformers rely on air as the cooling medium, rather than oil, and they need proper ventilation to prevent overheating. Placing them in a vault would restrict air circulation and increase the risk of overheating and failure. Therefore, the statement that dry-type transformers rated over 35KV shall be installed in a vault is false.