because they changed the code to allow pvc in hazardous areas ,in recent times, means expansion considerations are not necessary for it, where we did not worry about that for GRC Don....~RJ~Still have no idea of what you are trying to tell me. The "where necessary" applies to all of the permitted wiring methods in 501.10(B)(2).
Because rigid PVC conduit is not a flexible wiring method. 501.10(B)(2) is only about flexible wiring methods in a Class I, Division 2 location.how so Don?
The term necessary is a subjective term when you are trying to apply this rule. My only point is that there could easily be differences between the opinion of the installer and that of the inspection authority.In context, the use of words like necessary, sufficient, if, if and only if, are all describing an underlying Boolean logic form, formula, equation, or statement.
D = A and B and C ;. A B C D are Boolean data types, for D to be true, A, B, C are (all) necessary conditions (also must be true).
D = A or B or C ;, A, B, C are sufficient conditions. D is true if any sufficient condition is true.
meets_code = flexible and B and C. All are Boolean data types and the equation is evaluated by the rules for Logic. flexible (true or not) is a necessary but not sufficient condition for meets_code to be true.
The word necessary, in context, is used to describe a factor in a Boolean logic equation.
It is also called discrete math. That's where you will see necessary used, as it is used in your code reference.
Not the best picture but how about something like this (Class I Div II) bottom entry with limited space? Note: There is nothing in 501.10(B)(2) that restricts the need for flexibility to movement/vibration...Those types of things are not very likely in a Class I, Division 2 location.