GE Industrial Solutions GE ZENITH SERIES MDU - Manual (Page 9)

Installation Procedures
GE Z ENITH C ONTROLS
MDU Owner’s Manual
601 S HILOH R OAD January 2013
Plano, TX 75074 Page 9
3.2. System Grounding Recommendations
Note: Grounding for this equipment must not violate any local building or electrical codes.
System grounding has long been a topic affecting the computer equipment industry. The proper
grounding of your GE Monitored Distribution Unit is critical to the operation of the unit. Improper
grounding of a system may create unsafe conditions as well as electrical noise that may cause data
processing problems. GE has conducted a great deal of research on system grounding, and makes
the following recommendations.
3.2.1. Power System Grounding
The primary concern is to provide a safe system that both complies with the electrical code
(NEC article 250 in the USA, Canadian Electrical Code Section, 10, IEEE wiring regulations
and chapter 54 in the UK) and ensures proper and safe equipment operation. The MDU
should have a parity sized, green grounding conductor connected from the power J box to
the nearest grounding electrode. The MDU contains a factory wired, green grounding
conductor (within the power cable) from the power J box to a single ground point inside
the MDU cabinet. From this single ground point, each piece of equipment should be
separately grounded via a green grounding conductor within the flexible output computer
grade cable.
3.2.2. Grounding Conductors
An isolation grounding conductor identical in size, insulation material, and thickness to the
grounded and ungrounded branch circuit supply conductors should be installed as part of
the branch circuit that supplies the system. This grounding conductor should be marked
green (or green with yellow stripe) when using a (4) four wire system. A typical power wiring
diagram is illustrated in Figure 2.
This grounding conductor should be grounded at the nearest available grounding
electrode in accordance with all electrical codes. The output cabling receptacles of the
MDU should be the same grounding type. The grounding conductors serving these
receptacles should be terminated at the MDU ground bus.
Figure 2 provides the ground wire ratings.
Grounding for systems with Remote Panel boards:
Careful consideration should be given to the grounding of systems with remote Panel
boards. See FIPS PUB 94 or contact GE’s factory for recommendations.