SPLIT-CORE installation does not require the load conductor to be disconnected.
SOLID-CORE installation requires the load conductor to be disconnected in order to "thread" through the center of the CT.
CT installation inside the electrical panel must be done by a qualified individual or electrician. This individual must be knowledgeable and obey all safety procedures and local electrical code. See users manual for more safety information.
Make sure your service is not 3-phase or powered from two phases of a 3-phase source. The ECM-1240 is designed for 120V/240V split-phase systems only.
The SPLIT-170 CT is used in situations where the main panel uses rectangular buss bars instead of typical round conductors. (See example picture). The rectangular shape of this CT accomodates the buss bar where the SPLIT-200 CT would not.