KM6610 axis displacement monitoring instrument

Axial displacement is a very important signal for many rotating machinery, such as steam turbines, water turbines, turbo compressors, fans, centrifugal pumps, etc. It can reflect the clearance between the internal shaft (rotor) and the axial relative thrust bearing of the machine. The change in clearance can not only indicate the operating characteristics and conditions of the machine, but also indicate the wear of the thrust bearing and the risk of collision between rotating and stationary parts. The KM6610 axis displacement monitoring instrument can provide early warnings for long-term continuous monitoring of axial displacement, preventing damage to the machine caused by poor working conditions and resulting in economic losses.

The measuring disc displays the critical position of the rotor shaft:

1/5... Shutdown position

2/4... Emergency alarm location

3... Normal operating position

A. Measure relative axial displacement

The eddy current sensor.

The KM6610 axis displacement monitoring instrument is a highly reliable single channel axial displacement monitoring instrument that can continuously and reliably monitor the axial displacement of rotating machinery for a long time. The axial displacement input signal of the instrument comes fromKM1100Series eddy current sensors or other companies' complianceAPI670Standard eddy current sensor with digital display of displacement value. The probe of the sensor is installed along the axial direction, facing the measured surface which is the axial thrust flange or other flat surface on the shaft. This is a non-contact measurement method,API670The standard is recognized as the criterion for this measurement.

When designing and manufacturing this instrument, we adopted new and reliable digital electronic technology and components. Most of the internal components are surface mount components, and the metal chassis meets the on-site requirements for electromagnetic shielding. Due to the use of microcontroller technology, the measurement function of the instrument has become more excellent, and the configuration is more flexible and convenient. When debugging the system, it is not necessary to open the instrument box. All measurement parameter settings and functional configurations can be instantly completed on the panel buttons, making it very convenient to use. The high reliability of the instrument is based onPLCDesign requirements to ensure implementation. The built-in high-end microprocessor can continuously self diagnose sensors, instrument circuits, and software.

1. Main functions:

1. Range: optional, users can customize it during instrument selection, pre-set by the manufacturer.

2. Displacement direction:

Users can choose to have the side away from the probe as the positive direction, or the measured surface approaching the probe as the positive direction. The user can customize the instrument selection and it is pre-set by the manufacturer.

3. Display function:

The axial displacement measurement value, alarm value, and function code are displayed on the digital display window of the panel. The indicator lights of different colors on the panel are used to indicate the working status of the instrument panel.

4. Alarm function:

Users can set their own "alert" and "danger" values for displacement, and the indicator lights on the panel indicate alert and danger with the "alert" and "danger" alarms. The rear panel terminals provide alarm relay outputs.

5. Alarm delay function:

This function of the instrument increases the reliability of the alarm, and users can choose the delay time for triggering the warning and danger relays when selecting the instrument. This function is pre-set by the manufacturer.

6. Alarm reset function:

When an alarm occurs, the alarm reset is divided into two methods: self-locking and automatic reset; When self-locking, the alarm function is always maintained. After the monitoring situation is normal, the "reset" button needs to be pressed to reset; When resetting automatically, the alarm function will be automatically released after the monitoring situation is normal. Users can choose one of the methods when selecting instruments, and this function is pre-set by the manufacturer.

7. Self diagnostic function:

Any input system malfunction, such as probe rupture, circuit failure, etc., can be automatically detected by the instrument:“OK”The light is not on, and both the "warning" and "danger" alarm circuits are disconnected.

8. Sensor power supply current limiting protection:

When a sensor power short circuit occurs accidentally during use, the current limit should be ≤30mAIt will not generate sparks and meets the safety requirements of the monitoring site.

9. Record output:

Output analog signals proportional to the axial displacement range at the rear panel terminals, while providing4～20mAOutput terminal,And it has a short-circuit protection function.

10. Sensor signal buffer amplification output:

The buffered and amplified sensor raw signal is output from the rear panel terminal.

2. Technical Specifications:

Input:

1 Sensor inputKM1100Series eddy current sensors, with instrument range and sensitivity consistent with the sensor

Input points 1point

input impedance20KΩ

2 System inputs/Output conversion accuracy:

Record output ±1.0% 25℃

digital display ±1.0% 25℃

3 Frequency response:DC～5Hz（3dB）

4 Record output: 4～20mA(Load ≤500Ω)

5 Buffer Output:SIGBuffer signal level-1.2 ~ -23VOutput impedance500Ω (maximum)5mA）

6 Sensor power output:-24VDC±10%，15mAShort circuit current limit ≤30mA

7 reports Police:

Alarm Setpoint 4Point it（+Alert,-Alert,+danger-danger

Relay status Frequent power loss

Alarm relay output 2The group relays (warning, danger) are both normally open and normally closed

contact rating250VAC/1Aor30VDC/2A

alarm delay1~9SOptional, priority1S

Alarm reset: Automatic reset or self-locking, priority should be given to self-locking

8 rings Environment:

Operating temperature -20℃ ～70℃

Storage temperature -30 ～ 85℃

relative humidity 20 ～95%No condensation

9 Working power supply: 220VAC±10%，50HZ

10 Power consumption: ≤10W

11 Weight:1.5 kg

3. Unpacking and Installation

After opening the instrument packaging,Each instrument has one installation bracket, one certificate of conformity, and one user manual.

The installation position and structure of the instruments on the control cabinet are shown in the following figure:

4.Display and button instructions

Display window:

The front panel of the instrument panel is equipped with a4Digital display window, which displays monitoring values during normal monitoring work of the instrument; When performing functional operations, display functional parameter information.

L Status indicator light:

OK indicator light The normal indicator light is a green light-emitting diode,When it is constantly on, it indicates that the system is working normally; If it doesn't light up,It indicates that the sensor and the connected circuit are not working properly,At the same time, the alarm circuit needs to be disconnected, and the sensors, circuits, or instruments need to be checked. After troubleshooting, the system enters normal monitoring mode, and the lights automatically turn on normally.

Alarm indicator light The warning light is a yellow light-emitting diode,The hazard light is a red light-emitting diode used to indicate an alarm status. When the displacement reaches the warning value, the yellow light remains on,Alarm relay action; When the displacement reaches the dangerous value, both the yellow and red lights remain on,Warning and danger relay action. This light, in conjunction with the alarm reset function of the instrument panel, will automatically reset after normal monitoring,This light will automatically turn off when the alarm is cleared. In the self-locking state, the reset button needs to be pressed to turn off this light.

L Button Description:

On the instrumentFunctional OperationsWhen, shift the digital loop to the left1Position;

On the instrumentFunctional OperationsWhen, increase the corresponding digit1；

Clear the indicator lights of the instrument for alarm status and danger while monitoring, and reset the relay. When setting parameters, exit the current parameter setting state.

5. System connection and debugging

Diagram of Axial Displacement Monitoring System:

Connection of terminal block and signal transmission cable

Note:1Please do not use blank terminals.

2TheCOMandCOMDirect connection is not allowed, otherwise it may cause errors.

3When connecting the preamplifier of the eddy current sensor to the instrument or the preamplifier to the safety barrier, as well as the safety barrier to the instrument, please ensure that a three core shielded cable is used, and the shielding layer of the three core shielded cable is connected to the instrument, as the transmitted signal may be interfered withCOMThe front-end shielding layer is floating and wrapped. (It is recommended to use silver plated braided cables or flat shielded copper wires, with the core wire being soft copper wire).

4Avoid routing signal transmission cables together with control cables and power cables.

Attention: Insulation resistance between instrument ground and chassis ground500VDC≥500MΩ, allowing the chassis to be directly connected to the control panel

Screen to ground connection .

Attention: We strongly recommend that users chooseHC1100The series eddy current sensors have detailed instructions and regulations in the sensor user manual, including installation, calibration, correct operation methods for connecting with instruments.

5.1Correct installation of sensor probes

After correctly connecting the system according to the above requirements, the next step is to adjust the installation gap of the probe until the instrument display is zero.(If it is not zero and the value is0.05Internally, can be relocated to zero. The zero migration method can be found in the software settings)

Please note that the linear midpoint of the sensor may not necessarily be the zero point of the instrument, which means that when the sensor probe is installed at the linear midpoint, the instrument display may not necessarily be zero.

The zero point of the instrument is set at the factory according to the user's requirements for measurement range and direction, as well as the sensitivity of the supporting sensor. Therefore, when installing the sensor probe, the determination of the probe installation gap should be based on the requirements for measurement range and direction, and consider the sensitivity of the sensor.

Let me illustrate with an example

The required instrument range is-0.5~1.5mmFar away is positive, sensor2mmLinear, with a sensitivity of8V/mm

We can adjust the zero point according to the following steps

5.2Determine the sensor output voltage for the instrument zero point

From the direction away, it can be seen that the greater the distance between the sensor probe and the measured object, the greater the voltage value output by the sensor (without considering the negative sign in mathematical sense). The two are proportional to each other, and according to the negative range0.5,sensitivity8V/mmIt is known that the sensor's linear voltage at the zero point of the instrument=0.5*8=4VGenerally, eddy current sensors have a non-linear voltage before entering the linear segment, which does not vary with the gap of the sensor. This voltage is called the dead zone voltage. Our company2mmThe dead zone voltage of the sensor is2VTherefore, the sensor at the zero point of the instrument actually outputs a voltage=Dead zone voltage+Linear voltage=2+4=6V

Note: In fact, since the sensor is powered by negative voltage, the above voltages are all negative voltages, and the negative sign has been omitted for the convenience of description.

5.3Install sensor probe

According to the zero point sensor of the instrument, the actual voltage is-6VWe can adjust the gap between the probe and the measured surface, and use a multimeter to measure the preamplifierOUTandCOMThe output voltage of the terminal, read the multimeter display value as-6VAt this point, the instrument display should be zero.

5.4 Parameter Settings

In the parameter setting state, the left display window on the panel displays the parameter category to be set, and the right display window displays the parameter status (original parameter setting value) to be set.

press The key can cyclically change the number of digits required to set parameter values, while the corresponding digit's digital display flashes.

press The key can increase the current flashing value1Thus, the numerical values can be adjusted from0to9Cycle changes.

Current status:Represents the original set value.

Note: At any time during the above setup process, pressing the reset button can abort the current setup.

5.5Zero adjustment of instruments

There are two ways to zero the instrument, besides pressing the "Set" button as mentioned above, findAU0In addition to setting its parameters.

You can also use the following method: press the "Reset" button now, and then3Within seconds, press and hold the "▲" button until it displays as zero.

6. System verification

6.1 Under what circumstances should the monitoring instrument be calibrated

The instrument has not been used for a long time for more than one year

The material of the tested object does not match the factory calibration material

After troubleshooting

6.2 Calibration devices and equipment

Displacement calibration table(The material of the test piece is45Steel No)

Digital multimeter

L dial gauge

Eddy current sensor

6.3 operating process(To be matched with a Ø11Taking probe sensors as an example)

6.3.1First, verify the static displacement characteristics of the sensor (as shown in the following diagram):

The operation steps are as follows:

The probe is installed on the displacement calibrator.

Adjust the distance between the probe and the specimen to zero, and tighten the fastening screw. For ease of recording, it is recommended to adjust the dial gauge reading to zero.

Connect the 3-probe cable plug to the preamplifier socket (tighten).

Connect one end of a low-frequency three core shielded cable to the preamplifier end (marked)-24VTheCOMTheOUT）Connect one end to the instrument panel terminal block (marked)PWRTheCOMTheSIG）.

Adjust the hand wheel of the static calibration instrument to make the gap between the specimen and the probe end face the linear starting point of the sensor, and record the voltage value at this time.

Adjust the hand wheel of the static calibration instrument to make the gap between the specimen and the probe change equally, while recording the output voltage value and gap displacement value.

7 Calibration method: the output signal of the sensor corresponding to the gap change can be read on the digital voltmeter, and check whether the output displacement characteristic of the sensor is consistent with the factory calibration report of the sensor. Only sensors that are working properly can be combined with instruments to form a measurement system.If the tested material does not match the factory calibration material or there are doubts,Please contact us,We will provide you with a specialized measurement plan.

6.3.2．Instrument calibration and parameter setting:After confirming the output characteristics of the sensor, the specific calibration is the same as in the previous step5Chapter.

Attention: If users have special requirements for instrument functions, additional design and development are required. The model number will be marked with the word "non-standard" and a dedicated user manual will be provided with the instrument.

1. Adjust the hand wheel of the static calibration instrument to make the gap between the specimen and the probe change equally, while recording the output voltage value and gap displacement value.

2. Calibration method: the output signal of the sensor corresponding to the gap change can be read on the digital voltmeter, and check whether the output displacement characteristic of the sensor is consistent with the factory calibration report of the sensor. Only sensors that are working properly can be combined with instruments to form a measurement system.

If the tested material does not match the factory calibration material or there are doubts,Please contact us,We will provide you with a specialized measurement plan.

6.3.2．Instrument calibration and parameter setting

After confirming the output characteristics of the sensor, the specific calibration is the same as in Chapter 5.

Attention: If users have special requirements for instrument functions, additional design and development are required. The model number will be marked with the word "non-standard" and a dedicated user manual will be provided with the instrument.