Definite purpose and general purpose contactors

[srinaath]

I came across a contactor catalog saying "Definite purpose". Then tried to figure out the types of contactor.
Came across definite purpose and general purpose.
What is meant by definite purpose contactor and general purpose contactor?
On what basis can i choose definite purpose?

 

[anorlunda]

I never heard that exact phrase "definite purpose contractor" before. However, when building a house there is usually a general contractor plus electrical, plumbing, landscape, foundation contractors. I suspect that is what is meant.

 

[Rive]

I never heard that exact phrase "definite purpose contractor" before.

Neither I. However, by google the term exists.

But by checking it on the manufacturer pages, I could not find anything specific other than 'a sturdy contactor which we sell for a bit higher price'.

I hope somebody can share some insight.

 

[Asymptotic]

"Definite purpose" indicates a device designed to operate well within a specific application.

High power DC contactors are definite purpose, for instance, because they have arc blow-out, and other features specific to DC relays not found in general purpose contactors. They are also built more ruggedly than a run-of-the-mill contactor.

On the other hand, DP contactors designed for HVAC applications go the other way, and are less robust than equivalently rated NEMA general purpose contactors. They are physically smaller, their electromagnets aren't as powerful, and contact springs are lighter. The contacts themselves have smaller areas, and are thinner than their NEMA counterparts.

 

[anorlunda]

LOL. I read the OP as contractor, not contactor. Egg on my face.