Electrical Grounds; System And Facility Grounds; Recommended Ground Wire Sizes; Grounding The Invasive Procedure Room - GE Precision RXi Preinstallation Manual

GE M S P RX S P -I
EDICAL YSTEMS RECISION I YSTEM RE NSTALLATION
D 5123449-100, R 12
IRECTION EVISION
_____________________________________________________________________________________________
8.5.

Electrical Grounds

8.5.1. System and Facility Grounds

The ground for this system must originate at the system's power source and be continuous (i.e., transformer or first
access point of power into a facility, and be continuous to the system power disconnect in the room.) Ground
connection at the power source must be at the grounding point of the "Neutral/Ground" if a "Wye" transformer is
used, or typical grounding points of a separately derived system. In the case of an external facility, it must be
bonded to the facility ground point at the electrical service entrance.
The "system" ground can be splice using "High Compression Fittings" but must be properly terminated at each
distribution panel it passes through. When it's terminated, it must be connected into an approved grounding block.
Incoming and outgoing grounds must terminate at this same grounding block. Grounds must only be terminated to
approved grounding blocks. Grounds must never connect directly to he panel, frames or other materials in a cabinet
or distribution panel.

8.5.2. Recommended Ground Wire Sizes

The ground wire must be copper and never smaller than 1/0 AWG.
The ground wire impedance from the system disconnect (including the ground rod) measured to earth, must not
exceed 2 ohms (as measured by one of the applicable techniques described in Section 4 of ANSI/IEEE Standard
142-1982).

8.5.3. Grounding the Invasive Procedure Room

Invasive procedure room shall have all exposed metal parts that are likely to become energized, grounded to an
approved grounding bus located near the patient ground point (room ground point). Parts that are likely to become
energized include such things as high intensity lights or injectors, but would not include doorframes or monitor
booms. All room outlets and emergency power sources in the room shall have isolated ground receptacles with the
primary grounding coming from the power source and a secondary ground bonded to the room ground point. For
the receptacle or the electrical box which powers the injector power module there must be one ground wire back to
the room ground point even if the power module is in a separate room. The ground wire between the room ground
point and the patient ground point shall be copper wire of AWG #2 and not more than 10 feet long.
Where a ground fault circuit is used for room outlets, the ground wire to the room ground point shall be connected
on the primary ground of the ground fault detector to prevent tripping the detector. All ground wire impedances
shall be less than 0.1 ohms, when measured to the room ground point.

8.5.4. Grounding Critical Care Areas

Typically, R&F rooms are used as a critical care area and require a special grounding system for patient safety. An
equipotential grounding system is recommended for meeting patient safety requirements.
For some general system grounding requirements and information on establishing an equi-potential grounding
system, refer to:
Direction 46-104505, Electrical Safety – Equipment Grounding
Direction 46-014546, Electrical Safety – Leakage Currents
June 2009 Page 73 / 111