Types of relays?

[n00b 0f l337]

What are the types of relays and how do you figure out which one you need?

[star882]

What for? Different relays for different jobs.
Solid state - more expensive, but more reliable
dice-sized - most common, can handle from 1A to over 30A depending on size
large cube - used for large circuits, can handle from 25A to over 300A
reed relay - generally used only for signals and small circuits, 1A at most
starter relay - used to start motors, many different kinds

[n00b 0f l337]

For running a rotary that only needs a run cap.

[star882]

Use a SSR (solid state relay) or dice-sized relay of enough current rating. You may need a large cube if it's a large compressor.

[_HL4E_HalfLife_]

For running a rotary that only needs a run cap.

You don't need any relay on a rotary just a 25uf 240v run cap

[n00b 0f l337]

K and for a reciprocating?