This guide covers general recommendations for the operation and maintenance of indoor, openly-ventilated, dry type distribution and power transformers with Class B insulation in ratings above 50 kva and above 600 volts, cooled by natural draft or forced draft.The successful operation of these transformers is dependent on proper installation, loading and maintenance as well as on proper design and manufacture. As with all electric apparatus, neglect of certain fundamental requirements may lead to serious trouble, if not to the loss of the equipment. For this reason, a wide distribution of information in regard to the care of dry type transformers is important, and these brief instructions are published for that purpose.In addition to the use of this guide, the manufacturer should be consulted for specific recommendations on special conditions. Also reference may be made to other publications, some of which are listed in the Appendix.

This guide covers general recommendations for the operation and maintenance of indoor, openly-ventilated, dry type distribution and power transformers with Class B insulation in ratings above 50 kva and above 600 volts, cooled by natural draft or forced draft.The successful operation of these transformers is dependent on proper installation, loading and maintenance as well as on proper design and manufacture. As with all electric apparatus, neglect of certain fundamental requirements may lead to serious trouble, if not to the loss of the equipment. For this reason, a wide distribution of information in regard to the care of dry type transformers is important, and these brief instructions are published for that purpose.In addition to the use of this guide, the manufacturer should be consulted for specific recommendations on special conditions. Also reference may be made to other publications, some of which are listed in the Appendix.