TMC 7 Supplementary Protectors Phoenix Contact TMC 7 Supplementary Protectors are ideal for device protection in systems that require reliable overcurrent protection. The TMC 7 Protectors increase system reliability by isolating problematic circuits from an application, allowing the rest of the system to remain up and running. Phoenix Contact TMC 7 Supplementary Protectors feature Snap-Action technology, reducing wear and tear on the internal contacts of the device.