(1) If a change in type of service, such as from 25 to 60 Hertz, or a change in voltage to a customer's substation, is effected at the insistence of the utility and not solely by reason of increase in the customer's load or change in the character thereof, the utility shall share equitably in the cost of changing the equipment of the customers affected as determined by the commission in the absence of agreement between utility and customer. Note: The change in customer's equipment should be made with the greatest possible economy to the customer and final settlement made at the time of the change. Substantially the following basis was prescribed by the commission in Jackman v. Janesville Electric Co., 17 W.R.C.R. 356 and has been customarily adopted as the basis for settlement:
Payment by the utility to the customer of:
1. The remaining value of the customer's electrical equipment which is made obsolete;2. The cost of making the resulting necessary change in interior wiring; and3. The cost of installing the new equipment and removing the old, less the salvage value of such equipment as the customer retains.