NHP and Sprecher + Schuh are soon to release the new CT7N bi-metal thermal overload, which provides advanced protection features and a new look that fits the Sprecher + Schuh family of contactors and motor protection devices.
Sprecher + Schuh have always paid particular attention to the subject of motor protection and this is reflected in their new CT7N line of bi-metal thermal overload relays which include many features not available in most competitor products.
Consistent and reliable protection is ensured through a complex factory calibration procedure performed on each unit at full operating temperature.
Superior Class 10 characteristics – with today’s T-frame (MEPS) motors having less iron and copper than the older motors, a faster class 10 was needed to be developed to assure optimum protection, with the CT7N bi-metal thermal overload providing this necessary feature.
Protection from single phasing is a feature not always found in traditional relays, with the CT7N bi-metal thermal overload providing accelerated tripping under this condition through a special ‘differential tripping’ mechanism built into the CT7N bi-metal thermal overload.
Other features include:
- Selectable manual/automatic reset
- Separate normal open signal contact isolated from the trip contact (can be used on different voltage rails)
- Increased thermal capabilities for butting devices closer
- Can be used on single phase applications with all protection functions available – single phasing and class 10 protection
- A new adaptor external rest CT7N-RA3 provides a larger target surface for actuation.