Are Guardian Hazardous Area telephones field serviceable?

Hazardous Area Class I Division 2 and Class II Division 1 telephones are field serviceable.

Explosion proof telephones are not field serviceable. Maintaining the safety approvals require an authorized technician to service Explosion Proof area telephones.

For instance, in the case of the EXT-401, its ability to contain an internal explosion is based solely on the integrity of the enclosure. Therefore, the back panel of the telephone must be properly attached after being removed.