Ⅰ Noise caused by external structure of dry-type transformer and its solution
(1) Dry-type transformers generally have fan cooling systems. Abnormal noise from dry-type transformers is often caused by a failure of the fan system. Fans mainly have the following three types of fault phenomena:
①When the fan is put into use, it makes a "crackling" metal collision sound. This means there is foreign matter inside the fan, and the foreign matter needs to be cleaned.
② If the fan makes a friction sound when it is first started and it continues continuously, this is a quality problem with the fan itself. The fan must be replaced to ensure the normal operation of the fan system.
(2) A transformer with a protection level of IP20 or IP40 has a shell device. This shell will also be the source of transformer noise. The transformer will vibrate during operation. If the shell is not fixed properly, it will cause vibration of the shell, thus Noise is generated, so when installing the casing, it is best to add a rubber pad between the casing and the ground and between the casing and the transformer base to reduce the transmission of vibration sound.
(3) After entering the electrical room, you can hear a "buzzing" sound that is high and low in a certain direction of the transformer. This is the result of the superposition of sound waves generated by the vibration of the transformer and reflected by the wall. This situation is quite special. The space of the electrical room is related to the location of the transformer. At this time, the position of the transformer can be adjusted to reduce the sound, and some sound-absorbing materials can also be appropriately installed on the walls of the electrical room.
(4) Poor flooring or brackets at the installation location of the transformer will aggravate the vibration of the transformer and increase the noise of the transformer. The ground on which some transformers are placed is not solid. At this time, you will find that the ground will vibrate. You will feel the vibration when you stand next to it. In severe cases, you will see cracks on the ground. If this is the case, the location of the transformer must be reinforced to reduce the noise. .
Ⅱ Key points for selecting dry-type transformers
1. Select the transformer according to the load:
⑴. When there are a large number of primary or secondary loads, it is recommended to install two or more transformers. When any one of the transformers is disconnected, the capacity of the remaining transformers can meet the power consumption of the primary and secondary loads. The primary and secondary loads should be concentrated as much as possible and should not be too scattered.
⑵. ⑵When the seasonal load capacity is large, a special transformer should be installed. Such as the load of air conditioning refrigerators and electric heating loads in large civil S4270D27-29 27 2005.7.29,3:24AM buildings.
⑶. When the concentrated load is large, a special transformer should be installed. Such as large heating equipment, large X-ray machines, arc furnaces, etc.
⑷. When the lighting load is large or the shared transformer for power and lighting seriously affects the lighting quality and bulb life, a dedicated lighting transformer can be installed.
2. Select the transformer according to the usage environment:
⑴. Under normal medium conditions, oil-immersed transformers or dry-type transformers can be selected according to the situation, such as independent or attached substations in industrial and mining enterprises, agriculture, independent substations in residential areas, etc. Available transformers include S8, S9, S10, SC (B) 9, SC (B) 10, etc.
⑵. In multi-story or high-rise main buildings, non-combustible or flame-retardant transformers should be used, such as SC (B) 9, SC (B) 10, SCZ (B) 9, SCZ (B) 10, etc.
⑶. In places where dust or corrosive gas seriously affects the safe operation of the transformer, closed or sealed transformers should be selected, such as BS 9, S9-, S10-, SH12-M, etc.
⑷. High and low power distribution devices without flammable oil and non-oil-immersed distribution transformers can be installed in the same room. At this time, the transformer should have an IP2X protective shell for safety.