Daily frequency converter maintenance
Model: SY3200
Fault: no display
Fault analysis: the first measurement of the IGBT module is normal, the rectifier module is also normal. In order to prevent the occurrence of accidents, in addition to the power supply should be measured before the motherboard power + 5V and ground (GND) between the resistance value. The most simple method is to measure the resistance between the power supply pin and the ground. When the power plug is not inserted, the resistance is generally 300, the minimum should not be less than 100. Reverse the resistance value, a slight difference, but not too large. If the resistance is too small or close to the forward and reverse conduction, means there is a short circuit, by measuring the output 5V, +-15V, resistance is normal. Discharge after a short circuit led to the power supply is not shown, in the measurement of the switch tube is normal, the power on the measurement of the starting voltage 15V normal. But the latter level is not output. The primary circuit of the switching transformer is found in repeated measurements. Find the same transformer after the replacement of all normal.