GE Mark VIe System Manual page 141

6.5.3.2 Unit-specific Grounding Examples
The Mark VIe control system is applied in a variety of situations, using enclosures that are tailored for the end customer. Field
installers need to be well versed in best practices for grounding their equipment for the end customer. Various local guidelines
should be followed, as well as the site-specific installation drawings to determine the exact procedures for grounding the unit
controls.
With this in mind, it is not possible to provide specific procedures for all variations of field installations of the Mark VIe
control system. Properly trained field installers must perform this evaluation, verifying that the frame ground and power
ground only connect at one location prior to wiring the cabinet. When multiple installed cabinets are connected together with
base grounding plates (as displayed in the figure
in each cabinet bottom providing a separate parallel path for grounding. This may require opening ground path jumpers on the
power distribution boards and disconnecting wiring at the bottom of the adjacent cabinets. By temporarily opening the
connection from Functional Earth (FE) to the building grounding system, the installer can confirm if adjacent cabinet
connections to ground still exist. Once testing is completed, only one connection to FE per bonded set of cabinets is allowed.
If during inspection of the cabinet (prior to wiring the field devices) there are identified places where jumpers on the power
distribution system have ground connections, then pulling those jumpers could be a potential task. Normally, the grounding
systems connect to each other at only one location. The following figures provide an example where actions were taken to
disconnect wires and remove jumpers.
Installation Guidelines
Grounding Recommendations for Control Cabinet Lineup
F o r th is fie ld in s ta lla tio n e x a m p le , th e s e tw o w ire s
w e re d is c o n n e c te d fro m th e F E g ro u n d in g b ra c k e t .
Unit-specific Grounding Example (1 of 2)
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), this could result
GEH-6721_Vol_I_BP System Guide 141