Protection Relay (MELPRO-D series)
Product Features
It is digital protection relays for high/extra-high-voltage power distribution.
MELPRO-D series provides high performance and abundant lineup.
High Reliability
Adopt the highest performance CPU placed front end of the digital age
The high speed digital computation realizes the high accuracy operating characteristics never before possible. The operating characteristics are configured by the software, so that little deterioration and the stabilized operation can be realized.
Adopting self-diagnosis function for countermeasures against problem may arise.
The self-diagnosis function which monitors continuously the input, built-in power source and CPU is equipped. In the failures occurring of the relay, they can be detected immediately by the self-diagnosis function. Furthermore, dual output circuit makes possible to prevent the occurrence of misoperation due to the hardware failures.
Superior resistance to attack by tough environment
Adopt the structure to be resistant to the disturbances such as the electric surge and noise, the harmonics, the radio noise from the cellular phone, the temperature and the humidity.
High Performance
Suitable for advanced communication network system
Suitable for advanced communication network system
The communication network system enables the data acquisition such as measurement value, operation status and setting value as well as the remote operation such as the setting changes from the central control system.
Thereby, efficient operation and maintenance can be realized.
Local operation and monitoring for Site maintenance (Direct PC)
By connecting PC with relay via the RS232C port located on the relay panel, local operation and monitoring are enabled as same as the remote operation and monitoring.
Thereby, the maintenance work at site is strongly supported.
- ※Special HMI software (option) is needed for local operation and monitoring.
- ※Please refer to the specification table for each type of relay to confirm the capable of communication port and cards.
Communication network facilities with flexibility and extensibility.
In consideration of future communication network system variations and compatibility, communication features are installed in the relay using a replaceable card.
Thereby, it is plenty flexible and extensible.
Programmable output contacts complying with requirements on the flexibility
The operating output contacts can be set by combing the outputs of the protection relay element using “OR” logic, thereby simplifying sequence design. Also, it is possible to reduce the cost of switchboard as reducing wiring works.
Substantial measuring function
Substantial metering function
Possible to measure the steady state of the relay input values (Current, Voltage, Power, Frequency, Power factor, Zero phase current and Zero phase voltage), thereby possible to support the energy management.
Remark: Please note that measuring item is depended on the type of relay. Refer to the specification table of each relay type for the detail on this regards.
Data save in the event of system fault
In the event of system fault, input effective value and wave form data have been measured and stored at the time when one of the protection elements operates to issue an output signal.
Data for up to five phenomena can be stored and displayed.Therefore, analyze of phenomena becomes easy.
Replacement of existing relay
The dimension of the panel cutting is the same as the prior existing one.Replacing from the existing one to this new type is quite easy.
The dimension of the panel cutting is the same as the prior MULTICAP series. Replacing from the existing one to this new type is possible easily without using adaptor. Also, as this relay has a high degree of compatibility with the existing relay, the design change of the existing system is minimized. (Except for some types of relay)
Easy maintenance
Adopting draw-out unit mechanism enables easy maintenance and checking works
The draw-out unit mechanisms with automatic CT shorting is adopted, so that relay unit can be draw out without removing any parts or wirings. Thereby, it is possible to improve maintenance ease.