Jim, You can get further information on Class 1, Div 1, Group D from Factory Mutual Research Corporation (FMRC) and from UL and CSA. FMRC both have wall charts giving information on what the various Classes, Divisions and Groups mean. I think FM's is better but then I am biased.
Contact number for FM is (781) 762 4851 if you want to get hold of one. Or you can email at; approv...@factory-mutual.com Nick Ludlam
