RING-PISTON 1234268 - Caterpillar

Lead Numbering
The Wye configuration and the Delta configuration are the most common generator lead connections. The following three-phase connection diagrams illustrate the proper connection and lead identification.Wye Configuration Diagram
6 Lead
Illustration 1 g00611486
6 Lead Wye Configuration
Terminals T4, T5 and T6 become neutral connections when the terminals are tied together.
Delta Configuration Diagram
6 Lead
Illustration 2 g00669319
6 Lead Delta Configuration
Grounding the Frame
In any generator set installation, the frame of the generator must be positively connected to an earth ground. This connection should be the first connection that is made during installation. This connection should be the last connection that is removed. The ground connection must be flexible in order to avoid breakage during 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. The joints are frequent sources of radio frequency interference (RFI). Bolted connections should be silver soldered for the best performance.Neutral Connections
Generators with grounded configurations usually have a neutral that is grounded when the generator is installed. Ground the neutral in order to prevent equipment damage and personal injury. If the neutral wire is grounded and one of the phase leads becomes grounded, the excessive current will open a load circuit breaker in order to isolate the fault. If the circuit breaker does not open, then the excessive current will reduce the generator voltage to zero. The result depends on the characteristics of the generator, the type of fault, and the trip rating of the circuit breaker. An undervoltage device may be required in order to provide an adequate short circuit protection.Some installations do not require the neutral wire to be grounded. Ungrounded neutral leads are acceptable if measures have been taken in order to prevent grounds to the phase leads. An example of such measures are ground fault protective circuits. All of the distribution circuits must be treated as a system in order to ensure ground fault protection. The operator should contact a certified and registered consultant if a new distribution system is being developed. The owner should also engage a certified and registered consultant if an existing system should be modified for the ground fault protection. Neutral resistors and reactors may be added to the system for two reasons: to provide protection during faults and to limit neutral currents. Single Units
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 in order 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 generators in parallel, having all neutrals grounded, may result in the circulating current through the neutral connections. In order to eliminate the possibility of circulating currents, ground the neutral of only one generator. If multiple generators are alternated on line, a switch should be installed in the