Emerson VFD (Variable-frequency Drive) maintenance (1)

Before repairing Emerson series VFD (Variable-frequency Drive), you must understand the fault codes, otherwise you will not know how to start. I collect and organize these materials just to share with you, hoping to help you in your future work.

Fault code Fault type Fault code Fault type

POFF input undervoltage E008 Input phase loss

E001 Acceleration overcurrent E009 Output phase loss

E002 deceleration overcurrent E010 module protection

E003 Constant speed overcurrent E011 Inverter overheating

E004 Acceleration overvoltage E012 Rectification overheating

E005 deceleration overvoltage E016 read and write failure

E006 Constant speed overvoltage E018 Contactor not closed

E007 Control power supply overvoltage E019 Current detection circuit failure

1. Current detection failure (such as reporting E019, E001):

(1) The control board Q1 (15050026) is broken.

(2) 7840 is broken: When the VFD (Variable-frequency Drive) is energized, use the DC gear, connect the black to pin 5, and the red to pin 6, 7, and 8 respectively. The values of 2.5, 2.5, and 5 are normal, otherwise the 7840 is broken.

(3) The small board is broken: When the VFD (Variable-frequency Drive) is powered on, use the DC gear, connect the black to pin 5 of the 7840, and the red to the small board's pins from left to right should be 2.5, 2.5, 2.5, 3.4 1.5, 0, 1.6.

If the value is wrong, the small board is bad: at this time, replace the three small ICs (39030024 LMV393) in the bad small board, if not, replace the small board.

2. Display POFF:

Power on POFF on the driver board, and the measured CVD voltage should be 2.6-2.7 normally. If the measured value is 1.9, one of the R51, R52, C36, and C37 cables may be damaged, and the electrolytic capacitor is the most damaged. POFF is reported only when the motor is running, and the drive board transformer may be broken.

3. The buffer resistor is broken:

The snubber resistor and the large filter capacitor are paired. If one is bad, the other is likely to be bad too. The bad buffer resistance may also be caused by the relay not pulling in (the relay is bad or the control board is bad, or the components on the circuit connected to the two are bad). For single-phase input (220V) VFD (Variable-frequency Drive), special attention should be paid: if there is no display or crash, it is probably caused by the user connecting three-phase power (380V) (observe the fault record of the control board: whether the bus voltage has changed from 310 to 540). At this time, the rectifier bridge with continuous IPM is broken, and the large filter capacitor is also broken (or burst or the top surface becomes hardened). If you only replace the IPM and then turn on the power, you will hear a "pop, pop" sound (the sound in the capacitor), and you should power off immediately, otherwise the rectifier bridge of the IPM will be damaged again. It is found that a large capacitor is bad, it is best to replace it with a new one. Because capacitors are fragile and aging devices.

4. The display is unstable:

There is a display first, and then there is no display. The fan stops, and the voltage is only 12. This phenomenon is usually caused by the U1 thick film being damaged. Fault E015 is reported: the power-on indicator is on, but the keyboard is not on, just turn on the fan--the fan is short-circuited

5. No braking:

The brake tubes of 01180099, 01180100, 01180113, and 01180114 are not inside the IPM. VFD (Variable-frequency Drive) explosion and no display are probably caused by VFD (Variable-frequency Drive) shutdown braking. Therefore, after replacing the IPM, it is necessary to check the quality of the brake circuit: brake photocoupler, brake tube (MOS tube is not easy to test) , the freewheeling diode in series can be measured, which should be about 0.37 normally), the gate resistance (that is, the gate resistance of the MOS tube, which should be 100 ohms normally). After repairing and powering on, change TD900 F093 to 150, report E007, red connect to P(+), black connect to PB, if the voltage jumps at 17-30, the brake is normal. TD3200 F133=150 DC voltage 270-350V Brake works.

6. Frying the rectifier bridge:

If some of the rectifier bridges are damaged, but the inverter bridges are all good, it may be caused by sparks between the positive and negative busbars. Humidity is the main reason, generally there are water droplets on the positive and negative