<< Click to Display Table of Contents >> Navigation:  Drawing Environment > Symbol Insert Tool > Buttons, controls and views > Resource category view > 0-7: Help symbols and contact mirrors > 6 Main break contacts

 

Resource category 6 contains main break contacts of different kinds, and even a symbol with a combination of make and break contacts.

 

A main contact is dimensioned to handle a load, and is therefore a different kind of contact compared to a help contact.

 

"Break" is the correct term according to the IEC standard. Other popular terms for the same thing is "normally closed", "NC", and "opening".

 

Please note that when contacts are booked towards contact mirrors, different kinds of break contacts are separated. A main break contact and a help break contact are for example not considered to be same thing.

 

At delivery, only one function code for break main contacts is predefined. Would a need for additional types occur, it is easy to add more.

 

Break main contacts are not considered to have a direction and not to be asymmetric, even though that is not true geometrically speaking. From a functional perspective, it is however true. Therefore, these symbols are available in two versions each, one vertical and one horizontal.

 

Three and four pole main break contacts occupy multiple contacts in the corresponding contact mirror.

 

Variants of these symbols with our without the half circle that is supposed to differ main contacts from help contacts are functionally identical. In other words, you can choose either one, depending on what you prefer. To avoid any risk of confusion, the one with the half circle might however be the better alternative in most cases.