1. Moisture absorber (silicone tube): Silica gel inside. The insulating oil in the oil conservator is connected to the atmosphere through the moisture absorber, and the desiccant absorbs moisture and impurities in the air to keep the internal windings of the transformer in good condition. Discoloration or quality of silicone can easily cause clogging.
2. Oil level gauge: reflects the oil level of the transformer, usually around +200. If the oil level is too high, the oil needs to be drained, and if it is too low, then the oil needs to be added a little more.
The oil level does not change much, the oil level drops slightly when the temperature is low and the load is light in winter, When the load is heavier in summer, the oil temperature rises and the oil level rises slightly, both of them are normal.
3. Oil pillow: adjusts the oil volume in the oil tank to prevent transformer oil from overoxidation. There is an oil filling port on the upper part.
4. Explosion-proof pipe: Prevent sudden accidents from accumulating pressure in the fuel tank and causing the risk of explosion.
5. Signal thermometer: monitors the operating temperature of the transformer and sends a signal. Indicates the temperature of the upper oil of the transformer. The temperature of the transformer coil is 10°C higher than the temperature of the upper oil.
The national standard stipulates that the limit operating temperature of the transformer winding is 105°C (that is when the ambient temperature is 40°C), the upper layer temperature shall not exceed 95°C, and the monitoring temperature (upper layer oil temperature) is usually set at 85°C and below.
6. Tap changer: Change the voltage ratio by changing the tap of the high-voltage winding and increasing or decreasing the number of winding turns.
Normally, transformers perform no-load voltage regulation during power outages. Usually, the adjustment is divided into three gears: I, II, and III, which are +5%, 0%, and -5% respectively (primary winding 10.5KV, 10KV, 0.95KV, secondary winding 380V, 400V, 420V). It is generally set to II modes when leaving the factory.
7. Gas signal relay: This is used for light and heavy gas signal protection. The upper contact is a light gas signal, which is generally used as a signal alarm to indicate abnormal operation of the transformer. The lower contact is a heavy gas signal, when the signal is sent, the circuit breaker will trip, fall, and alarm.
Normally, no gas will be in the tank if the gas relay is filled with oil. If there is gas, it will get into the relay. When it reaches a certain level, the gas crowds out the oil and actuates the contacts.
Open the cover of the gas relay and you will see two adjustment levers on the top. Unscrew one of the caps to release the gas inside the relay. The other adjustment lever is the guard test button. Insulated gloves must be worn when working on hot wires.