Signal Reference Grids: Grounding Solutions with Exceptional Results

ALLTEC Oct 07, 2009

Proper bonding and grounding are essential factors in today's quest for ultimate power quality, and it is critical to have a system that is driven by both safety and performance. Alltec Corporation's Signal Reference Grids (SRGs) are used around the world in communication/data centers to reduce static and noise and to protect equipment. SRGs are cost-effective, easy to maintain, and very successful at protecting equipment from voltage surges.

The Need for an Equipotential Plane

Electronic equipment is typically affected when there is a potential difference between devices. Proper grounding and bonding of sensitive electronic systems, including computer installations, require careful consideration of all frequencies. Alltec's SRGs provide an equipotential plane for equipment where all electronic and electrical equipment connected can rise and fall together. These signal reference grids (SGRs) reduce or eliminate high frequency transients by achieving a common ground reference for all equipment within an adjoining area. The equipotential grid significantly decreases potential differences and diminishes current flow, thereby eliminating the adverse affect on logic circuits.

Requirements

Signal Reference Grid installation is normally required when:

The logic ac-dc power supplies used in the electronic equipment are installed with one of the terminals connected to the equipment's metal frame. This prevents damage to inter-unit signal units by providing a low-inductance, and hence, effective ground reference for all externally installed AC and DC power, telecommunications, or other signal level line to-ground chassis connected Surge Protection Devices that may be used with the associated equipment.

The signal-level circuits and logic ac-dc power supply common terminals are OEM dielectrically insulated or galvanically isolated from equipment against recommended practice and are instead connected to an insulated "ground" terminal that is intended for connection to an externally installed signal reference circuit.

There are actual performance problems occurring with the equipment which can be assigned to common-mode electrical noise; they are used to prevent or minimize damage to inter-unit signal-level circuits and equipment power supplies when a power system ground-fault event occurs.

Signal Reference Grids as Grounding Solutions

The purpose of Signal Reference Grids is to enhance the overall reliability of the signal transfer between interconnected items of equipment by reducing the inter-unit common mode electrical noise over a broad band of frequency. All metallic enclosures, conduit, and ductwork should be bonded to the Signal Reference Grid for it to function properly.

Advantages of a well designed Signal Reference Grid

Low-impedance return path for RF noise currents

Containment of EM (noise) fields between their source and the plane

Increased filtering effectiveness of contained EM fields

Shielding of adjacent circuits or equipment

Forms of available Signal Reference Grids

Conductive grid embedded in, or attached to, a concrete floor

Metallic screen under floor tile<

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Ceiling grid above equipment

Supporting grid of raised access flooring

Alltec Corporation designs and manufactures copper wire ground grids for grounding applications. Typical ground grids are manufactured from #6 solid copper on a 6" spacing. All connections are welded with silver brazing or can be exothermically welded for an additional cost. Copper ground grids are available with a continuous perimeter wire or with extended grid wires for making connections to additional grids. For more information on signal reference grids contact us today at 1 800.203.2658 or pr@allteccorp.com. Also, visit our website @ www.allteccorp.com.