Alternators, Models & Design, Part 2, 10SI Variations

The Delco 10SI marine units have a screen behind the fan inside the case and a screened cover that covers the rear half of the unit.  This is to make the unit explosion resistant so if there is a spark inside the unit, it won't ignite the gas fumes that accumulate around the engine on inboard units.  The unit pictured below is a 'one wire' unit, but they do make a plug with two wires sticking out of it for regular wiring.  There is also a grounding tab and bolt just above and to the left of the battery post.

 
There is even an external regulated version that allows you to use the 10DN plug like the alternator on the previous post-part 1, where the regulator is removed and a terminal block is used in it's place.  Notice the spade terminals go in a different direction than in the regulated units. 

Other internal variations include regulators with 6, 8 and 24 volt settings and a reverse rectifier for a positive ground system.  The 24 volt works best with a stator and rotor that is wound for that output.  There are some units that have three spade terminals and the third one in the offset position is a stator tap, which is usually used to run an electric tachometer.  Another variation of this uses a post that goes into the hole labeled 'R' beside and above the battery post.  This can be added to any 10SI unit except marine!

Another variation uses modern produced housings for replacing other brand units.  The first one is a Prestolite replacement.  This unit also has screens for marine purposes as a lot of these particular units were used on boats.  This type of mounting may replace some foreign brand tractor units also, though lining up the pulleys can be a problem.

And this unit below is used for replacing Motorola units which are usually found on old tractors and equipment!