Abstract: The present disclosure relates to a method 200 of controlling a system 100, 100?, 100? including a heating arrangement 130 for heating a process medium 140, a current sensing arrangement 180, and a switching arrangement 120 configured to selectively couple a power supply 110 to the heating arrangement, the switching arrangement comprising at least one semiconductor switch 120A, 120B, 120C. The method 200 comprises: in response to a demand signal 224 for starting heating of the process medium 140, operating 204 the system in a test mode 230. Operating the system in the test mode 230 includes performing a test sequence 230A.

Abstract: An improved frame for a switchgear cabinet includes a plurality of rails that are connected together with a plurality of connectors. The rails are generally of two different cross-sectional configurations, both of which are cooperable with a single type of connector to enable the rails and connectors to be configured into numerous different types of cabinet frames to which panels can be mounted to form switchgear cabinets. The rails and connectors are modular in nature and are specifically configured to be easily connected with one another. During assembly of the connectors and the rails, portions of a coating on the rails become ruptured, thereby electrically conductively connecting together the rails and the connectors.