Fault Phenomenon and Troubleshooting for Temperature Humidity Test Chamber and Vibration Testing System

This is the training course about the fault phenomenon and troubleshooting for temperature humidity test chamber and vibration testing system|In any system, multi-point grounding will cause a ground loop between the loops. The electromagnetic field output from the power amplifier generates voltage in these loops, which forms ripple noise, and this noise is superimposed on the signal voltage, And amplified by the power amplifier and input into the moving coil, Unwanted clutter will be generated on the moving table. This problem is commonly known as ground loop.

To reduce this problem, a little grounding needs to be taken on the system equipment. There is a dedicated ground point (PE) at the connection terminal of the power amplifier. Usually the output of the vibration and vibration controller is connected to the power amplifier and the connection between the accelerometer on the table and the vibration and vibration controller will form a loop. Sometimes the accelerometer and the vibration table can be insulated to reduce the loop noise. If there is no effect, you can give vibration An isolation transformer is added to the vibration controller.

When the vibrating table is far away from the power amplifier, the long cable between the devices will cause greater voltage drop and more serious problems. In this case, there must be a large area to connect the coaxial cable, The potential is as close as possible.

Horizontal and Vertical Vibration System

Protection NameFault PhenomenonTroubleshooting
Pump PressureThe oil source is not turned onTurn on the oil source (horizontal slide)
OvercurrentThe output current exceeds the rated value, the light is onReduce output current, or check excitation and voice coil
Module OvercurrentThis light is on when the components in the module are damaged or there is a momentary overcurrent1. Replace damaged module|2. After reset, Restart
Overdisplacement When the table displacement exceeds the rated value, this light will be on Reduce displacement and check the center position of the table
Overvoltage The output voltage exceeds the rated value, the light is on Reduce the output voltage
Module OverheatingWhen the temperature of the module radiator exceeds 85 ℃, this light will be on Reduce module heat sink temperature
Machine OverheatedWhen the temperature of the lower end of the magnetic circuit of the table body exceeds 110 ℃, this light will be onLower the body temperature
Power Supply OvervoltageThe three-phase AC power is monitored by the DC amplifier, and the light is on when the three-phase power supply is overvoltage 10%Reduce three-phase voltage
Power Supply Undervoltage operating Amplifier in standby The content is the same as above, the light will be on when the voltage is under 10% Increase three-phase voltage
OperatingAmplifier in standby.
Zero SignalThe amplifier output potentiometer did not return to the “RESET” position and press “ON”The output potentiometer returns to the “RESET” position
Leakage Switch TripThere is leakage in the lineIdentify the cause of leakage and eliminate it

① Eliminate the trip faults listed above.Reset Method
② The output signal of the vibration controller is reduced to zero.
③ The “gain” knob of the power amplifier is turned counterclockwise to the “reset” position, and the protective indicator is off.
④ Turn the power amplifier “gain” knob clockwise to the desired position.
⑤ Re-input the signal to the power amplifier according to the vibration controller manual.

(1) Identification method of fan turning. After the system is started, because the speed of the fan is too fast, the direction of the fan rotation of the motor on the fan cannot be seen clearly:

After the system is started, when the fan rotates for about 5 seconds, the main power air switch in front of the power amplifier cabinet can be turned off to cut off the power. Since the speed of the fan is not very high at this time, the wind machine will stop slowly in a relatively short time. Before stopping completely, you can clearly see the direction of rotation of the fan blades on the motor.

(2)Deal with the inconsistent rotation direction of the fan and the turn sign. When it is found that the rotation direction of the fan is inconsistent with the turning sign, it can be handled as follows:

After the fan is completely stopped, at this time, the main power air switch in front of the power amplifier cabinet is in a position to cut off the power, open the rear door of the power amplifier cabinet, and exchange any two phases in the three-phase power line U1V1W1 delivered to the fan Just one click. You can also wait for the fan to stop completely, open the junction box of the motor on the fan, and exchange any two phases inside.

Conversion Formula for Vibration Calculation :Matters Needing Attention
a (m/s2) = 2πf V = (2πf)210-3D/2 = 0.002f2D …(1)
D(mm) = (2×1000 × a ) /(2πf)2 = 50.7a / f2 …(2)
D(mm) = V×1000 /πf = 318V/f … (3)
a(in/s2) = 19.72f2D … (4)
D(in) = 0.051a/f2 … (5)
D(in) = 0.318V/f …(6)
In the formula: f means frequency|Unit: Hz
a mean Acceleration (single peak)|Unit: m / s2 or in / s2
V mean Speed (Single Peak)|Unit: m / s or in / s
D mean Displacement (peak-to-peak value)|Unit: mm or inch

Fault Phenomenon and Troubleshooting for Temperature Humidity Test Chamber and Vibration Testing System

(3) If the equipment has been moved or the power supply has been changed, also make sure that the direction of the fan operation is correct. Otherwise, due to the incorrect direction of the fan, the heat in the vibration machine body cannot be removed in time, which will burn the vibration machine.

Check Item for Temperature Humidity Test Chamber and Vibration Testing System: The user should checks the following items during inspection: The functions of small indicators, switches, knobs, and meters are often kept intact and without exception. This is the check list for agree chamber, not the troubleshooting advice.

Check ItemTest Content
Between V + and VAbout DC 160V
O1 and V+About 1/2 V + -V-
O1 and V-About 1/2 V + -V-
AC1 to AC2< C30mv
DC1 and DC2About DC270V
Power Amplifier Unit
Check ItemTest Content
Table ScrewsCheck whether the installation screws and screw holes are damaged
Vibrator voice coil and up and down guideUse an oscilloscope to observe whether there is clutter in the acceleration waveform when the voice coil is no-load
Air Spring Vibrating machine with maximum load drops less than 4mm in 24 hours
OtherWhether there is abnormal sound during no-load vibration
Vibration Body Device

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