Pass-through porcelain insulators look simple: a case with ribs, a hole for the live part, and familiar markings. This provokes dangerous logic. Its essence lies in the fact that if the part fits the diameter and is designed for 250 A, then it can be installed. But in the case of transformer equipment, this approach does not work. The error will be detected during installation or already during operation.
What is hidden behind similar requests?
In the catalog of the Kontur-M company there is no separate item insulator IPT 6 for 250 A. The full name of the product is IPT-6-10/250 A O1. It is designed for voltage classes 6 and 10 kV. Therefore, the request for the IPT 6 10 insulator does not lead to two interchangeable models, but to one product.
The IPT-6-10/250 A O1 has a leakage path length of at least 20 cm, a height of 240 mm, an outer diameter of 130 mm, and a weight of 2.2 kg. The insulator is manufactured according to GOST 13871-78 and GOST 5862-79. And this data helps you choose the right product. Therefore, you should not just specify "6 kV" and "250 A".
What is the difference between the 10 kV option only?
The IPT 10 insulator request covers a whole group of products. For example, the IPT-10/250 B O1 is also designed for 250 A and has an outer diameter of 130 mm. Based on the photo, it is easy to mistake it for a close analogue of the 6-10 kV model.
But the parameters vary. The IPT-10/250 B O1 has a leakage path of at least 30 cm, height – 295 mm, weight – 3 kg. The same current and outer diameter do not guarantee the same dimensions and installation conditions.
Why is the label written in full?
It is convenient to type queries such as insulator IPT 6 250 for the search, but they are not enough to purchase a suitable product. The request does not include a range of 6-10 kV, the letter A and the climatic version O1. The entry insulator IPT 6 10 250 also remains a search term. The specification needs a factory marking: IPT-6-10/250 A O1.
Therefore, before placing an order, you need to check:
- full name and voltage class;
- Rated current;
- the letter A or B and the execution of O1;
- drawing, height, and mating dimensions.
There is one more nuance. "O1" starts with the letter "O", not with zero. There's not much difference to the search, but there's no need for ambiguity in the application.
It is impossible to choose an IPT based on a photo, even with the same current and outer diameter. The 6-10/250 A and 10/250 B models have different electrical and dimensional parameters. In the catalog of the Kontur-M company, you can check the specifications and drawings. When selecting a replacement, you should attach a photo of the marking and dimensions of the removed part to the application. It's cheaper, easier, and faster to fix bugs in the future.