U2Slow:
You sure that's not just a Siemens main breaker? That's the same arrangement that GE uses for their mains in their TM series panels. How would you handle the load connection if this breaker was plugged onto the regular bus bar? Parallel #6 conductors to the load? I don't think so.
Those four-pole breakers are for specially-designed main breaker mountings only. They have factory bus bar extensions or adapters to fit into the lugs of the breaker. Also, unlike in a regular panel where adjacent poles are on different legs, the four-pole mains are configured with the two poles on the left being on one leg and the two on the right being on the other.
The breakers like the Square D and Siemens ones that Roger and E57 posted illustrate the true four-pole breakers. They are also available (or were) available from C-H the last time I checked. They take up two poles on the left AND right side, so technically they are still occupying four full pole spaces.
I have also seen 70 amp stabs, but usually in panels that have spaces designed to accept piggyback breakers at the bottom. Since the stab isn't full-size so that piggybacks will only fit where they belong, their rating isn't as high as the full-size spaces.
[This message has been edited by EV607797 (edited 12-14-2006).]
