According to the National Electrical Code (NEC), it is legal to hardpipe to a transformer, but only under certain conditions.

Section 450.21(A) of the NEC states

> "Conductors entering transformers or vaults shall be protected against physical damage. Where space is limited, conductors installed in accordance with the provisions of Article 300 are considered to be adequately protected."This means that if the conductors entering the transformer are installed in accordance with the requirements of Article 300 of the NEC, they are considered to be adequately protected against physical damage.

However, there are some exceptions

Conductors installed in a raceway with a removable cover are not considered to be adequately protected against physical damage. Conductors installed in a cable tray are not considered to be adequately protected against physical damage unless the cable tray is enclosed or guarded.If the conductors entering the transformer are not installed in accordance with the requirements of Article 300 of the NEC, they must be protected against physical damage by other means, such as installing them in a rigid conduit or pipe.

Therefore, it is legal to hardpipe to a transformer, but only if the conductors entering the transformer are installed in accordance with the requirements of Article 300 of the NEC, or if they are protected against physical damage by other means. Flag for review