G333 & 3306 NATURAL GAS ENGINES Electric Set Operation Instructions Caterpillar

Electric Set Operation Instructions
1.1. General
2.2. Safety Precautions
3.2. Identification
4.2. Three Phase Neutral Connections
5.2. Voltage Connections


Proper engine operation and maintenance are essential to long engine life and maximum performance. The essentials for proper operation and normal periodic maintenance are outlined in this guide. However, your AVSpare dealer is available for troubleshooting and/or repairs when required.

Before starting the engine, familiarize yourself with these procedures. Even though your engine may not be equipped with the exact attachment illustrated, the operating procedures will be similar.

This guide contains information for AVSpare Statically Regulated Controlled Rectifier (SRCR) and SR 4 generators. AVSpare SR 4 refers to the brushless type generators. Study the guide carefully and apply the principles to your particular installation.

Safety Precautions

Safety is basically common sense. There are standard safety rules but each situation has its own peculiarities which cannot always be covered by rules. Therefore, your experience and common sense will be your best guides to safety. Watch for hazards. Correct deficiencies promptly.

You can do something about safety. Lack of attention to safety can result in: accidents, personal injury, reduction of efficiency and worst of all-loss of life.

Use the following safety precautions as a general guide to safe operation.

1. Observe NO SMOKING signs.
2. Do not wear loose clothing around machinery.
3. Be sure the engine room is properly ventilated.
4. Do not smoke around batteries. Hydrogen gas generated by charging batteries is explosive. Keep batteries in a well ventilated area.
5. All electrical equipment must be grounded according to local building codes.
6. Remove tools and electrical cords from the engine before starting.
7. All fans, shafts, pulleys, etc. must have guards.
8. Check all connections periodically for tightness and insulation.
9. Never adjust or repair a machine while in operation.
10. Never operate a diesel engine with the governor linkage disconnected. Human reactions are not fast enough to control the fuel rack.
11. Do not touch the heat sink on the generator regulator when the generator is running. It is electrically "hot".



12. Always disconnect and tape the ground battery lead before working on the electrical system.
13. Be sure the remote starting system is inoperative when the engine is being worked on. Disconnect the starter from the start switch.
14. Always disconnect the engine starter circuit when working on the generator.
15. Keep the engine room and floor area clean.
16. Store oily rags in metal covered containers.
17. Never store flammable liquids near the engine.
18. Insulate all connections and disconnected wires.
19. Do not use carbon tetrachloride fire extinguishers. Fumes are toxic and the liquid has a deteriorating effect on insulation.
20. Do not work on electrically "hot" equipment.



Voltage Setting

Generators are set at the factory for the voltage and type of operation specified. Voltage control initial adjustment instructions are located inside the generator exciter and regulator access cover. These instructions are for adjusting the generator output to nameplate ratings. For further adjustments, see page 5 for single and parallel unit operation.

Generator Serial Number

The engine serial number is stamped on the engine information plate and on a plate on the left side of the block toward the rear. The generator serial number is stamped on the generator nameplate and on the right side of the generator frame forward of the terminal box. Requests for information and orders for parts should be accompanied by the engine and generator serial numbers.

1. The group of numbers before the letters indicates generator frame size. The letter T may appear before the first group of numbers. This indicates a "tropicalized" generator, that has been dipped in epoxy to prevent moisture entrapment in windings.
2. The letter T is the symbol for AVSpare Statically Regulated Controlled Rectifier generators. The letter B is the symbol for AVSpare Statically Regulated Brushless Excited generators.
3. The next letter indicates the voltage rating of the generator as follows:

4. The last group of numbers are the actual serial numbers of the generator in the frame size and voltage rating. Always use the complete serial number.

Generator Lead Numbering

Each coil lead is marked according to the following diagram.

Numbering is clockwise from the top and from the outside in. Terminal T0 is the neutral lead on all high voltage connections. On low voltage connections T0 is connected with T4, T5, and T6 to form the neutral terminal. The standard generator diagram and the terminal connections are on the nameplate of each generator.

Three Phase Neutral Connections

Single Units

Three Wire: In a three phase, three wire system, the generator should normally be grounded according to local wiring codes. In some cases, however, it is undesirable to ground the neutral wire. For example, on boats a grounded neutral may increase the problem of electrolysis. In applications where definite measures are taken to prevent grounds to the load leads, an ungrounded neutral can be used. Be sure to check your local wiring codes.

Four Wire: In a three phase, four wire system, the neutral wire should be grounded according to local wiring codes. For only single unit operation, there should never be a need for a disconnect switch, or device, in the neutral line.

Multiple Units

Operation of multiple generators in parallel, having all neutrals grounded, may result in current circulating through the neutral connections. To eliminate the possibility of circulating currents, ground the neutral of only one generator. If multiple generators are alternated on line, a single pole single throw knife switch should be installed in the neutral ground circuit of each generator, so all but one neutral ground circuit can be opened. Be sure one neutral ground circuit is closed.

Voltage Connections

Three Phase

The connections for both high and low voltage are given in the following chart.

The terminals must be connected securely and insulated with a good quality electrical tape.

Single Phase Current From A Three-Phase Generator

Three phase and single phase current can be taken simultaneously from a generator connected for three phase service. Connecting any two of the three phase leads will provide single phase current at the same voltage as three phase power. Connecting a three phase lead to neutral will produce current at 58% of the three phase voltage. DO NOT exceed the nameplate current rating for any one phase.

Single Phase

When a generator is connected for single phase operation, do not exceed these limits:

1. The nameplate amperage limits.
2. Fifty-eight percent of the KVA and KW ratings. (The engine will only work about half as hard.)

Three phase (230-460V and 115-230V for SRCR) and (240-460V, 125-250V and 208-416V for SR 4) generators can be connected for two or three wire service at either voltage. When generators are connected for three wire service both high and low voltages may be obtained simultaneously without reconnecting the leads. In this case DO NOT ground T0. Generator neutral is not T0 but a point in the windings electrically half way between T1 and T8. This point is not wired to a terminal.

To reconnect the generator for single phase voltage follow the chart. Wrap all connections and unused terminals with a good grade of insulation.