Determines the performance, materials and construction and performance tests for pressure switches with two sets of independently adjustable electrical contacts. The pressure switches are for use on oil-filled cable systems covered by ESI 09-3, 09-4 and 09-5. There are two Classes of switches, defined as follows: Class 1 - Suitable for indoor and outdoor locations exposed to the atmosphere and subject to ambient temperature variations within the limits of -10 deg C and +40 deg C, but not liable to flooding. Class 2 - Suitable for locations liable to flooding and subject to ambient temperature variations within the limits of 0 deg C and +25 deg C. Such conditions generally exist in pits or chambers below ground level.