...
Class B same as Type 1 (build in main electrical cabinet)
Class C same as Type 2 (lightning protection, can withstand indirect impact)
Class D same as Type 3 (protections in devices, in our case - varistors)
...
Class B same as Type 1 (build in main electrical cabinet)
Class C same as Type 2 (lightning protection, can withstand indirect impact)
Class D same as Type 3 (protections in devices, in our case - varistors)