ZKZ-3

ZKZ-3   Gear Disc Residual Pressure Speed Monitoring Device 
Delivery date: STOCK  
WS 


1、 Overview
ZKZ-3T speed monitoring device is externally connected with speed pulse sensor and voltage transformer signal to monitor the speed of water turbine generator unit in real time, and output switch signals and analog signals corresponding to unit speed at each speed point of the unit, serving for automatic startup, shutdown and power plant monitoring system.


2、 Features
■ ZKZ-3T speed monitoring device is a multi-purpose speed monitoring instrument, which integrates frequency meter, tachometer, speed relay and speed testing instrument;


■ The speed measurement adopts the advanced measurement principle of the period at the side of the transformer gate, which has the characteristics of high measurement accuracy and strong real-time;


■ The measurement and control accuracy of the device only depends on the error and stability of the crystal oscillator, so the outlet value of the speed contact can maintain long-term operation without change;


■ Speed contact output adopts return difference locking mode to prevent output misoperation caused by waveform distortion. According to the operation needs of the power plant, 8 speed outlets can be conveniently located on site


The value can be adjusted within a certain range.


■ The device also has standard 4~20mA current output and optional RS485 (MODBOS RTU) communication output, which can be conveniently connected with the computer monitoring system of the whole plant


Connect.
3、 Main technical performance


■ Number of measuring signal channels: one pulse signal, one PT signal (or permanent magnet machine signal)


■ Measuring frequency range: 0.05~100Hz


■ Measurement accuracy: nonlinearity ＜ 1%, speed dead band ＜ 0.02%


■ Digital display contents: generator frequency, speed percentage, output setting values of each circuit.


■ Switch output signal: speed value signal: 8 channels, each point can be set by the user within the specified range.


■ One channel of unit creep alarm output signal (SPST)


■ One channel of device power failure alarm signal


■ Analog output: 4~20mA (corresponding to unit speed 0% Ne~200% Ne)


■ Communication output: RS485 (MODBOS RTU)


■ Working environment: temperature 0~50 ℃, humidity<85%


■ Overall dimension: disc mounted 160 × eighty × 250mm


■ Working mode: continuous


■ Power supply: DC110 ～ 340V or AC85 ～ 265V/50Hz


■ Power consumption: 12W


4、 Working principle
ZKZ-3T speed monitoring device consists of three parts: gear disc, sensor and monitoring device body. The monitoring device adopts a high-speed single-chip microcomputer system. The internal frequency division of the system generates a measurement timing pulse with a period of 2us. Its measurement accuracy can reach 0.01HZ. It has high stability and remains unchanged for a long time. The display circuit adopts a high brightness dynamic display scheme with high brightness. The signal measuring circuit has the functions of isolation, amplification and shaping. The two signals are completely independent. When the gear disc signal is disconnected, it automatically cuts into the PT signal. The signal voltage within 0.3V~250V can work reliably for a long time, and the signal voltage within 300V can also work reliably for a short time. The speed measuring gear plate takes its square wave signal into the computer, and then converts the corresponding frequency, speed, speed percentage, etc. to provide display and memory. ZKZ-3T speed measuring device has the unit creep alarm function. When the unit shuts down and creeps, it will send out a creep alarm signal.