The Motor Protection Relays MMPR-620Hb Application Scope:

The MMPR-620Hb microcomputer motor protection applies to the protection and monitoring of medium and Medium-voltage motors with voltage ratings of 3kV~11kV. It can be used for the integrated protection of large and medium motors of different capacities, and also for the dual configuration of main protection and backup protection of ultra-large motors.

1. Protective function

• Prolonged start time protection (Start Time Over)
• 2-section definite time limit over-current protection ( instantaneous over-current protection,  locked rotor  protection) (Overcurrent)
• Negative sequence over-current protection(NS Overcurrent)
• Zero sequence over-current protection(ZS Overcurrent)
• Overload protection(Overload)
• Overheat protection(Motor Over Heat)
• Underload protection(Underload PROT)
• voltage protection (Under-voltage protection, Over-voltage protection) (Voltage PROT) 
• Non-electric quantity protection(2-way)(Non-electric)
• Logical control(Joint Trip PROT)
• Out-of-step protection(Synchronous motor)(Out-Of-Step PROT)
• Asynchronous impact protection(Synchronous motor)(Asynchro.Impact)
• Longitudinal differential protection(Longitudinal Dif)
• Magnetic balance differential protection(Mag.Balance PROT)

2. Auxiliary function

• Under-frequency unloading (Under-frequency)
• Soft start function(Soft Startup)
• Harmonic spectrum analysis
• Phase display
• Integral energy and impulse energy
• Self-checking fault alarm of device
• Remote calling and modification of protection’s settings
• Fault recorder(Wave Record)
• 2-way programmable output of 4~20mA.

3. Monitoring function

• Electric quantity(remote measuring quantity): voltage, current, active power, reactive power, active energy,  reactive energy, power factor, grid frequency, non-electric quantity measuring, etc.
• Remote binary quantity: the device has 15-way binary input, in which: 12-way for external gathering, and 3-way for internal gathering.

4. Communication capability

• 2 standard RS485 multipoint communication ports
• 2 industrial ethernet ports
• Supports single, dual network communication, it is fully qualified for network redundancy and  backup
• IEC-60870-5-103 (RS485 communication mode ),IEC-60870-5-104 (industrial ethernet  mode)  standard  communication protocol.

5. GPS clock synchronization function

• The device is able to receive GPS clock minute synchronization (or second synchronization) through  RS485 differentiate  voltage, and it can be done with monitoring system to  accomplish GPS precise  clock  synchronization.