CRITERIA FOR IMPLEMENTATION
Before commissioning the drive, it is essential to have read the respective manual, where the manufacturer provides information about previous tests to be performed in the stages of power and control.
The method described below can serve as a reference test used primarily in analog-type drives. These tests should be performed while the drive without power supply.
CHECK STATUS OF THE POWER STAGE
Uncover the computer drive and check the status of the diodes and thyristors making up the amp. Notice that there are two parts, which correspond to the armature circuit and field power. Use a digital multimeter LED scale, see Figure 2-22. It is important to have knowledge of the controlled rectifier type implemented by the manufacturer.
Check the fuses, cables connecting the power terminal blocks, splices, bridges that serve to adjust the amplifier for various levels of supply voltage (110VAC, 220VAC, 380VAC, 440VAC), sensors current and speed, etc..
Through careful observation to determine if there is dirt, dust and moisture. Proceed to clean with a dry lint-free cloth or at least with a bristle brush to avoid static problems.
After the procedure, your computer drive must be reassembled and prepared for the next phase.
CHECK STATUS OF THE STAGE OF CONTROL
Without applying energy and using the manufacturer's manual, make the joints connecting the power terminals and control.
The power terminal block can be described generally as follows: (See Figure 2-23)
Where:
The terminal blocks L1, L2 and L3 is the power input VAC voltage level set in the previous procedure (to be taken as an example a three-phase variable speed are the most commonly used at industrial level). These line voltage rectifier circuit feeding the armature and field.
The terminal blocks + A and-A are the output of the rectifier will be responsible for feeding the DC armature voltage.
The terminal blocks + F and-F are the output of the rectifier will be responsible for feeding DC voltage to the motor field.
During testing the power amplifier, the outputs of the armature and field power terminals are connected to lamps that simulate, for the moment, the role of these coils.
The control terminal block (see Figure 2-24) is described as follows:
Normally:
The terminal L1, L2 and L3 is the same voltage that feeds power to the terminal (unless otherwise specified by manufacturer). The entry "Run" operation can enable the drive.
The potentiometer is Vreferencia speed reference signal (in clockwise rotation sliding point must unite with + V)
The terminal block + DT-DT is the entrance to the speed feedback signal that normally connects to the tachometer, but in this test case, is replaced by a DC power source of appropriate value.
The testing of the control stage is:
Adjust the DC source Vreferencia and the minimum (counterclockwise).
Switch Off / must be open.
VAC voltage feed terminal blocks both. The lamp represents the field coil will light immediately.
Close the switch Off / Reverse. The lamp represents the armor must remain turned off (unless the minimum speed setting is different from zero).
Slightly rotate the knob clockwise until Vreferencia note that the lamp begins to light armor. This increase slowly increasing light (indicating that the drive has ramp acceleration) until it reaches the maximum voltage possible as armor plate on the drive.
Turn slowly clockwise until the DC source lamp to note that the armor begins to fade away (indicating that you ramp down) to minimum illumination.
If the drive responds as indicated above lines it is concluded that the control stage is operative.
Turn off and unplug the drive test joints.
