ALTERNATOR GP-CHARGING 1776972 - Caterpillar

Small Frame SR4 Generators With Single Phase Wave ExcitationDescription of Change: A new voltage regulator assembly is now used in the above generators. The new regulator design uses a new A1 and A2 module regulator assembly and a new R3 gain rheostat. The new A1 module uses a solid state voltage build-up circuit instead of a mechanical relay. The new A2 module uses a new rectifier that has a higher current rating and has faster recovery (return to normal condition). This decreases electrical noise and radio interference. The new 500 ohm R3 gain rheostat has a larger diameter wire than the former 5000 ohm rheostat and will give a longer service life.
Adaptable As: The new regulator assemblies are a direct replacement for the former regulator assemblies as shown in the chart. The former parts are canceled. For field replacement of the former A1 module regulator assemblies, a replacement kit is available. The kit has a new A1 regualtor assembly and R3 gain rheostat with a Special Instruction, Form SMHS8323. The Special Instruction gives complete installation instructions. See the chart for the replacement kit part numbers.