A. The provisions of this chapter shall not apply to those industrial or commercial appliances which are to be used in a special location and which have been submitted to a laboratory for approval to determine their conformity with the standards provided for in this chapter but with respect to which final approval by such laboratory is still pending, providing that an exception is applied for and granted in the manner prescribed.

B. The person desiring to make such installation shall submit an application in writing for such exception to the chief electrical inspector accompanied by written evidence satisfactory to such inspector indicating that laboratory approval has been applied for.

C. Such exception if granted by the chief electrical inspector shall continue in force only during such time as such inspector believes that the testing laboratory will grant final approval certifying compliance to the prescribed standards.

D. If for any reason the chief electrical inspector believes that the testing laboratory has not made an adequate test of materials, devices or appliances, he may require that the same be submitted to some other laboratory, approved by him, for further tests. (Prior code § 7.22.120)