Emergency power transformer failure has a short circuit […]
Emergency power transformer failure has a short circuit, open circuit, poor insulation from the bow and so on.
When the transformer failure, it should promptly check the replacement, especially the emergency power transformer, the emergence of the smell, smoke, the output voltage is reduced and the temperature is very fast, you should cut off the emergency power supply to find out where the fault. What are the methods of detecting emergency power transformers?
1) Detection of the first and second winding on and off, the multimeter placed in the Rx1 block, the two test leads were hit once the winding of the two leads, the resistance is generally tens of several - hundreds of Europe, if ∞ was broken, If there is 0 resistance, it is short circuit. With the same method to measure the resistance of the secondary winding, usually a few tens of oh (step-down transformer), such as the secondary winding when there are multiple, the output voltage is smaller, the smaller the resistance; coil disconnection, No voltage output, the reasons for the open circuit off the outer bow line, lead and solder soldering, moisture after the internal chrome and so on.
2) to detect the winding, winding and core purposes Insulation resistance multimeter placed in the Rx1Ok block, a pen connected to a winding of a lead, the other table were connected to the secondary winding lead, the multimeter said resistance should be If this value is less than this value, it indicates that the insulation performance is poor, especially if the resistance is less than several hundred ohms, indicating that there is a short circuit between the windings.
With the above method and then continue to detect the insulation between the winding and the core resistance (a table pen then core, another writing pen to take the winding bow outlet).
3) If the emergency power transformer appears "buzzing" sound, you can press the transformer coil, if the "buzzing" sound immediately disappeared, indicating that the transformer core or coil loose phenomenon, there may be a fixed position of the transformer loose.
4) test transformer secondary winding no-load voltage transformer transformer once connected to 220V emergency power supply, the multimeter placed in the AC voltage block, according to the transformer secondary winding nominal value, selected multimeter range, followed by two The no-load voltage of the secondary winding, the allowable error should not exceed 5% -10% normal (in the case of a winding voltage of 220V).
If the secondary voltage is increased, indicating that a winding has a local short circuit fault, if the secondary winding of a coil voltage is low, indicating that the coil has a short circuit.http://www.linsheng.com/