TECHNICAL BULLETIN TB-2003 Common Point Grounding Units Made in the United States of America Installation Instructions Description Per ANSI/ESD S20.20, all conductors, including personnel, must be electrically connected and attached to a known ground. EOS/ESD S6.1 recommends hard ground, without resistor, of worksurface or floor mats. Per ANSI/ESD S20.20, ground fault circuit interrupters (GFCI) should be considered to provide personnel protection. Desco offers a number of common point grounds and wrist strap ground connectors designed to ground multiple operators or items. Figure 4. 09835/09836 quad common point ground The 09835/09836 quad common point ground is designed for use as either a wrist strap ground connector or as a common point ground. The quad ground incorporates four standard banana jacks, a 10mm snap stud, and ten feet of ground wire terminated with a ring terminal with a 0.200 I.D. hole. The model 09835 also incorporates a 1 megohm resistor in series with the snap stud. Figure 1. 09740/09741 wrist strap bench ground. The 09740/09741 wrist strap bench ground is a wrist strap ground connector and consists of a mounting bracket with two standard banana jacks installed and soldered to a ten foot ground wire termin ated with a ring terminal with a 0.200 Figure 5. 09820/09821/09825/09826 common point ground. hole. The 09820/09821/09825/09826 common point ground The 09741 includes a wrist strap parking station. See figure 2. is designed to ground bench mats by snapping on the mats stud, and to provide a convenient wrist strap ground connector. Items 09820/09821 incorporate two standard banana jacks, a 10mm snap socket, and 10 feet of wire terminated with a ring terminal with a 0.200 I.D. hole. Items 09825/09826 have a 10mm snap stud and 15 feet of wire. Items 09821/09826 also incorporate a one megohm resistor in series with the snap. Figure 2. 09741 premium bench mounted ground with parking station The 09842 Multi Grounding Hub is designed for use as either a wrist strap ground connector or as a common point ground for all items to be grounded at a bench (i.e. table mat ground cord, floor mat ground cord, banana jack ground block, etc.). The Multi Grounding Hub incorporates six standard banana jacks, and six terminations for ring Figure 6. All elements at the ESD work station should be terminals (10-32 screw in threaded holes). connected to the same common point ground, such as 09842 Multi Grounding Hub. The 09740/09741, 09835/09836 and 09820/09821/09825/09826 are shipped with an extra ring terminal so that the ground wire may be cut to length during installation. The 09740/09741 and 09835/09836 feature a pair of mounting holes designed to accommodate standard 10 screws, allowing the units to be Figure 3. 09842 Multi Grounding Hub mounted to the work bench. DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 (909) 627-8178 DESCO EAST - One Colgate Way, Canton, MA 02021-1407 (781) 821-8370 Website: Desco.com 2019 DESCO INDUSTRIES INC TB-2003 Page 1 of 3 Employee OwnedProper Grounding Installation Wrist straps, work surfaces, floor mats and other electrostatic After you have selected and tested your grounding point, discharge (ESD) protective products should be grounded to a you will need to determine the method of installation common point ground. for the type of grounding block that you have selected. Installation of common point units as grounding blocks is outlined below. Installation of the 09835/09836 and COMMON POINT GROUND 09820/09821/09825/09826 as common point ground cords Per ANSI/EOS/ESD S6.1, Grounding para graph 4.1.1 Every for a work surfaces is also discussed below. element to be grounded at an ESD protected station shall be con nected to the same common point ground. WRIST STRAP GROUND CONNECTORS 1. Select the most convenient location on the work bench for ESD Handbook TR 20.20 paragraph 5.1.3 Basic Grounding grounding of wrist straps and other grounding devices. Requirements The first step in ensuring that everything in an EPA is at the same electrical potential is to ground 2. Position the 09740/09741 or 09835/09836 and use the all conductive components of the work area (worksurfaces, two 10 mounting holes to secure to the work bench. people, equip ment, etc.) to the same electrical ground point. This point is called the common point ground. The next step 3. Bring the wire neatly back to your grounding point. You in completing the ground circuit is to connect the common may wish to use wire brackets to hold the wire in place point ground to the equipment ground (third wire, green). and out of the way. Cut and strip the end of the wire to properly fit your ground point. Install and crimp the extra If all elements are connected to the common point ground, ring terminal provided. even if the equipment ground connection is compromised, all workstation elements will be connected and be at equi potential or at the same charge. Being at the same electrostatic charge will mean that no discharge should occur. Connect the ground wire directly to the nearest utility green wire ground point. In a properly wired building, the green 09835/09836 09740/09741 wire equipment ground point may be the center screw of the Figure 8. Installation of grounding blocks. standard 110VAC outlet. Some special outlets may float the center screw. Test before you hook up. 4. To check resistance, use an ohmmeter from the banana BANANA PLUG CAN BE jacks to the common ground point. It should read less than ATTACHED HERE 1 Ohm AC impedance for items 09740/09741,09820/09825 6 and 09835 and 1 megohm (10 ohms) for items 09836 and GREEN WIRE 09821/09826. EQUIPMENT RING TERMINAL CAN BE GROUND ATTACHED HERE POINTS GROUNDING POINT BANANA PLUG CAN BE As previously mentioned, the 09835/09836 and the ATTACHED HERE 09820/09821/09825/09826 can be installed as a wrist strap ground connector for ESD protective work surfaces. Figure 7. Recommended grounding point. 1. Position or lay the work surface in the desired location. Individual work stations must be individually grounded to Snap the ground to it. These units connect with a 10mm the green wire equipment ground. For ESD worksurface socket snap. installation information, see Desco Technical Bulletin TB-2000. 09835/09836 Always Test the Ground Before You Use It and Periodically Thereafter You should not assume that any electrical outlet is properly 09820/09821/09825/09826 wired. Even if it was originally wired correctly, it can become ungrounded due to corrosion and wear. Test the equipment ground you intend to use before you hook up. Use Desco 98130 AC Outlet Analyzer to verify proper wiring of the electrical outlet (equiment ground). Figure 9. Installing the 09835/09836 and 09820/09821/09825/09826 as a common point ground cord for a work surface. DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 (909) 627-8178 DESCO EAST - One Colgate Way, Canton, MA 02021-1407 (781) 821-8370 Website: Desco.com 2019 DESCO INDUSTRIES INC TB-2003 Page 2 of 3 Employee Owned