SHIELD 2509273 - Caterpillar

All SR4 GeneratorsIntroduction
This instruction provides the parts and information needed to retrofit a VR3 Voltage Regulator into all SR4 generators.The VR3 voltage regulator is installed using either a 7C9120, 7C9121 or 7E5031 Bracket depending on the type of terminal box design.The bracket used, and the method of installation, is dependent on the terminal box design of the generator.The 7C9120 and 7C9121 Brackets can be installed by welding into position or by drilling four holes and using screws and nuts to secure.
The 7E5031 Bracket can only be properly installed by drilling and bolting into position. Installation by welding, due to the limited clearance, can damage other parts.
Use the Mounting Bracket Usage Chart to find your particular application before proceeding to "Preparation Before Installation" section of this instruction.Do not perform any procedure, outlined in this publication, or order any parts until you read and understand the information contained within.Reference: SENR3473, VR3 Voltage Regulator Supplement for SR-4 Generators (10/12 Lead, Self-Excited). SENR3904, VR3 Voltage Regulator Supplement for SR-4 Generators (4/6/Lead, Self-Excited).SENR3905, VR3 Voltage Regulator Supplement for SR-4 Generators (Permanent Magnet Excited).Service Magazine (December 21, 1987), Improved VR3 Voltage Regulator Available for Earlier Generators.Service Manual, SENR3985, "SR4 Generator With VR3 or VR4 Voltage Regulator".SENR4794, Schematic, "Connection Diagram: SR4 Generators, VR3 and VR4 Voltage Regulator Options".Mounting Bracket Usage Chart
Preparation Before Installation of VR3 Voltage Regulator
Read and understand all safety precautions and warnings before operating or performing any service or repair on this product.
When servicing or repairing electric power generation equipment:* Make sure the unit is off-line (disconnected from utility and/or other generators power service), and either locked out or tagged DO NOT OPERATE.* Make sure the generator engine is stopped.* Make sure all batteries are disconnected.* Make sure all capacitors are discharged.
When power generation equipment must be in operation to make tests and/or adjustments, high voltage and current are present.Make sure the testing equipment is designed for and correctly operated for the high voltage and current tests being made.Improper test equipment may fail and present a high voltage shock hazard to its user.
Protecting the Regulator and Other Generator Components During Parts Installation
Before any parts installation the unit should be prepared to prevent:* Any metallic debris (when installing by drilling method) from accumulating on other components.* Any welding splatter (when installing by welding method) from contacting other components and/or contacting any combustible areas or surfaces.Electrical Connection Preparation
All electrical connections are to be made directly to parent materials only.* Any paint, corrosion or lubricant must be removed from mating surfaces prior to connection.* Use only plated (or otherwise corrosion protected) hardware to make connections.Necessary Parts
The following parts (not included with the 7C9120, 7C9121 and 7E5031 Brackets) are required to install the VR3 Regulator into the appropriate bracket and to secure the bracket to the terminal box. They must be ordered separately. Removing the Existing Voltage Regulator and Installation of (If Equipped) Excitation Transformer (4/6 Lead SE)
1. Remove access cover.2. Remove existing regulator and mounting bracket. If equipped with excitation transformers proceed to Step 3, if