CLIP 4P5918 - Caterpillar

Lead Numbering
Each coil lead is marked according to the following diagrams. The diagrams contained show the four, six, ten, and twelve lead configurations available in present day SR4 generators.The standard generator diagram and the terminal connections are on the nameplate of each generator.Numbering is clockwise from the top and from the outside inward.
4 Lead Wye Configuration
6 Lead Wye ConfigurationTerminal T4, T5 and T6 become the neutral connection when tied together in the 6 Lead Wye Configuration.
10 Lead Wye ConfigurationTerminal T0 is the neutral lead for the 4 lead and 10 lead generators.
12 Lead Wye ConfigurationTerminals T10, T11, and T12 become the neutral connection when tied together in the 12 Lead Wye Configuration.
12 Lead Delta ConfigurationIn the 12 Lead Delta Configuration Terminals T6 and T9 become the neutral connection when tied together and grounded, reflecting the Terminal T2, T10 connection as the high phase.Grounding the Frame
In any generator set installation, the frame of the generator must be positively connected to an earth ground or to the hull of a vessel. This connection is the first one made at installation, and the last one to be removed. If the generator set is on flexible or resilient pads, the ground connection must be flexible to avoid possible breakage in later operation.Ground connection cable or straps should have at least the current carrying capacity of the largest line lead to the connected load. Joints in cables or straps must be clean, free of electrical resistance, and protected from possible oxidation. Bolted ground connection joints eventually oxidize, and are frequent sources of radio frequency interference. Silver soldered, bolted joints are electrically and mechanically sound.Neutral Connections
"Y"-connected generators usually have the neutral grounded when the generator is installed unless definite measures are taken to prevent grounds on the load side. The grounding of the neutral is to prevent load side equipment damage.If the neutral wire is grounded and one of the phase leads becomes grounded, the excessive current will open a load circuit breaker or collapse the generator voltage. The result depends on the particular generator electrical characteristics, type of fault, and circuit breaker trip rating. An undervoltage device may be required to provide adequate short circuit protection.There are some instances in which it is undesirable to ground the neutral wire. In these applications where definite measures (ground fault protective circuits) have been taken to prevent grounds to the phase leads, an ungrounded generator neutral lead is acceptable.Ground fault protection requires that the entire group of distribution circuits be studied and treated as a system. The owner should engage a certified and registered consultant if a new distribution system is being developed, or if an existing system is to be modified for ground fault protection.Single Units
Four Wire: In a three phase, four wire system, the neutral wire should be grounded according to local wiring codes.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.Multiple Units
Operation of multiple