AC ELECTRICAL CONNECTIONS — SYSTEM GROUNDING

System Grounding (continued)

Figure 36 below illustrates a typical system grounding for a 3-pole and 4-pole Automatic Transfer Switch (ATS).

3-Pole ATS

In the 3-pole ATS, note the generator neutral is connected to the ATS and is NOT bonded to ground at the generator. A neutral to ground bonding jumper is factory installed in all industrial gensets. Remove the jumper from the alternator saddle box to meet electrical codes and grounding requirements if required.

4-Pole ATS

In the 4-pole ATS system, a grounding electrode conductor and a bonding jumper are used to connect the generator neutral to ground. In some installations, a current transformer (CT) may be required for ground fault monitoring.

Bonding and grounding must be performed properly. All metallic parts that could become energized under abnormal conditions must be properly grounded. Failure to do so can cause electric current to flow, causing severe injury or death!

Typical requirements for bonding and grounding are given in the National Electrical Code, Article 250. All connections, wire sizes, etc. must conform to the requirements of the electrical codes in effect at the installation site.

Figure 36. Typical System Grounding

INDUSTRIAL GENERATOR SETS — APPLICATION & INSTALLATION MANUAL — REV. #4 (09/07/07) — PAGE 77

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Multiquip MQP30GM, MQP20IZ, MQP40IZ, MQP45GM, MQP60IV, MQP50IZ, MQP30DZ AC Electrical Connections System Grounding, Pole ATS