三相设备(如三相压缩机、三相电机等)在使用三相电源供电时，传统的做法是通过试接来保证三相程序接入。在试接的过程中，必然存在三相逆相接入的可能，时间虽短，但对设备亦有一定的损害。 

更为严重的是：三相电源常常因雷击，外力作用而出现三相中的某相断路，造成缺相。如果不能在运行过程中对三相设备进行缺相保护，则会使三相设备在断相情况下异常工作，轻则设备运行不正常，重则烧毁三相设备。

三相电源实时监控器监测相序L1、L2、L3和三相中任何一相的丢失，当相序正确，输出继电器激活，通过黄色指示灯LED显示。

1.三相设备在逆相接入时，该保护器输出一个开路信号，切断三相设备控制电器电源，使其停机。

2.只有在三相顺序正常接入时，保护器才允许三相设备控制电路得电工作。

3.在设备运行过程中，当三相电某一相断路造成缺相时，保护器立即动作，切断控制电路电源，保证三相设备不在非正常状态下工作。

Working Principle

When three-phase equipment(such as three-phase compressor,three-phase motor)uses three-phase power supply,the traditional way is to test connection to ensure it is connected in right order,and inverse connection is surely possible to happen in the course of connection.It shall cause some damage upon the equipment even the time of inverse connection is short.

The more serious problem is:due to reasons of lightning of external force,one phase shall be often opened.If no open phase protection is available during the operation course of three-phase equipment,it shall operate abnormally under open phase condition or shall be burnt if the case is serious.

The three-phase power supply real-time monitor shall monitor the order of phases L1,L2and L3and check if some phase is opened.If the phase order is correct,the output relay is energized and yellow LED indication lamp shall light.

1.In case the three-phase equipment is conncted in reverse order,the protector shall output an open circuit signal to swith off control power supply of the three-phase equipment to stop the machine.

2.Only three phases are connected in right order,can the protector allow the control circuit of the tree-phase equipment to energize and to run..

3.During the operation course of the equipment,if one phase is opened,the protector shall act immediately to switch off the control circuit thus to ensure the three-phase equipment not to operate under abnormal status.

保护特点：

动态缺相、静态缺相保护：指被保护设备在运行状态或非运行状态，任意一相发生断相故为：黄灯灭。

错相保护：防止L1、L2、L3三相交流电源相序接错的一种保护措施。即时动作。指示灯形式为：黄灯灭。

Characteristics of protection

Dynamic phase-lacking protection and static phase-lacking protection, which starts to work if one phase opens when the protected equipment is in operating course or un-operating state. The yellow indicator lamp goes out.

Error-phase protection: It is a protection method preventing L1, L2 and L3 three-phase power supply connecting incorrectly. It can work instantly and the yellow indicator lamp goes out.

性能特点：

监视器的保护功能能够全性能、全气候长期工作。功耗不大于25W；

本产品通过CE认证。

Performance characteristics:

The monitor can exert its protection function wholly and in any climate for a long time. The power≤25W；

This product has pass CE Certification.

工作特点：

L1、L2、L3三相接线正确，监视器黄灯亮，继电器吸合；如果相序接错，监视器黄灯灭。

L1、L2、L3三相或任何一相丢失（相对丢失的临界值100V），监视器黄灯灭。

Work characteristics:

If three phases L1, L2 and L3 are in a correct connection, the yellow indicator lamp is on and the relay picks up; If the phase sequence is connected incorrectly, the yellow indicator lamp goes out;

If three phases L1, L2 and L3, or any phase is opened (the critical value of phase failure is 100V), the yellow indicator lamp goes out.

技术参数：

环境温度：-25℃―- +55℃

相对温度：< 90%

外型尺寸：68mm×30mm×72mm

Technical  Parameters：

Environment temperature: -25℃ ―- +55℃

Relative humidity :< 90%

Dimension:68mm×30mm×72mm

输入(Input):

操作范围 Operaion Range 230～440V3～

电源电压 Voltage of Power Supply 200～500V

频率 Frequency 50/60HZ

最大功率 Maximum Power 25W

输出(Output):输出继电器 Output Relay 两个无镉转换接触点 

(Two cadmium-free transferable contacts)

输出电流 Out put Current 8A

最大断路电压 Maximum breaking Voltage 440V～

额定断路功率 Rated Breaking Current 2000VAC

最小断路电流 Minimum Breaking Current 10mA/5A

电器寿命 Life of Electric Appliance 交流12×105(在8A/250V时)

AC12×105(under 8A/250v time)
机械寿命 Mechanical life 2×107次(time)

传感延时 Sensor Relaying T1＜200ms

断开延时 Breaking Relaying T2＜300 ms

运行温度 Operating Temperature -20℃～+50℃

存储温度 Storage? Temperature -30℃～+70℃

如有下列故障发生,继电器断开(LED熄灭)

In case following troubles occur,the relay is switched off (LED goes out):

1．在端子L1、L2和L3相位产生错误相序；

1．Wrong order of phases occurs in terminals L1,L2and L3.

2．三相或任何一相全部丢失（相对丢失的临界值100V）。

2．One phase or all three phases is opened (the critical value of phase failure is 100V).