TECHNICAL BULLETIN TB-3049 Ground Hub Continuous Monitor Operation, Installation and Maintenance Made in America more than just a few volts between ground and neutral, this indicates either that they are not referenced to each other or that the outlet and associated wiring should be checked for loose connections. In this case, the Ground Hub Continuous Monitor will sound a warning alarm and display a red FAIL indication and should not be used for an ESD grounding point until corrected. Use the Ground Hub Continuous Monitor to fulfill the ANSI/ ESD S6.1 section 6.3.1 requirement. The hot, neutral and equipment grounding conductor shall be verified to be in the proper wiring orientation in accordance with the National Electric Code (ANSIINFPA-70). The Ground Hub Continuous Monitor is available in the following models: Figure 1. Desco 19219 Ground Hub Continuous Monitor Item Voltage Plug 19219 120VAC N. America 19224 220VAC Asia / UK Packaging 1 Ground Hub Monitor 6 10-32 x 1/4 Screws 6 10 Split Washers 1 Certificate of Calibration Features and Components Neutral Figure 2. Desco 19224 Ground Hub Continuous Monitor Load / Hot Ground Description The Desco Ground Hub Continuous Monitor confirms the Ground Hub integrity of the resistance path from the common ground point to electrical ground. It is designed in accordance with ESD TR 12-01 to monitoring equipment ground Outlet Status connections. When the Ground Hub Continuous Monitor is plugged into an AC outlet, the green LED illuminates when both the outlets wiring is correct and the path to equipment ground FRONT VIEW BACK VIEW via the equipment grounding conductor is intact. The monitor provides 12 verified ground points when in PASS condition. Figure 3. Desco 19219 Ground Hub Continuous Monitor The red LED illuminates when either the outlets wiring is features and components incorrect or the path to equipment ground is defective. The outlet ground line is tested by measuring voltage between it and the neutral line. It is normal to have a few volts of AC induced on the neutral line. If the Ground Hub Continuous Monitor measures only a few volts, the ground line to neutral impedance is low and the ground line would make a suitable ESD ground point. If the monitor measures DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 (909) 627-8178 Fax (909) 627-7449 DESCO EAST - One Colgate Way, Canton, MA 02021-1407 (781) 821-8370 Fax (781) 575-0172 Website: Desco.com 2014 DESCO INDUSTRIES, INC. TB-3049 Page 1 of 3 August 2014 Employee OwnedEarth Load / Hot Neutral Outlet Status Earthing Point FRONT VIEW BACK VIEW Figure 4. Desco 19224 Ground Hub Continuous Monitor features and components Operation Plug the Ground Hub Monitor into an outlet to see if the green PASS LED illuminates. This signifies that the outlet is correctly wired and the path to equipment ground is intact. The screw that holds the outlet cover on may be used to secure the Ground Hub Monitor so that it cannot be unplugged. Use the included screws and split washers Figure 6. Ground Hub Continuous Monitor in-use photo to connect ring terminals (not included) to the Ground Hub or the banana jacks (not included) to connect banana plugs TESTING THE GROUND HUB MONITOR (see Figure 5). NOTE: The following procedure should only be done by (Wires not included) someone familiar with voltage hazards. This procedure will work for 220VAC as long as the neutral and ground are referenced. 220VAC produced with out of phase 110VAC- Ground-110VAC will produce a FAIL result. Isolate the ground plug from the Ground Hub Monitor by inserting the monitor into a 3 to 2 plug adapter. A. PASS OUTLET - Connect a 5 kilohm resistor 5% tolerance between the supply ground and tester ground. The PASS LED should remain illuminated until the resistor is removed. This test confirms the PASS point for the neutral-to-ground resistance. B. FAIL OUTLET - Connect a 12.5 kilohm resistor 5% tolerance between the supply ground and tester ground. The FAIL LED Figure 5. Installing ring terminals and banana plugs to should remain illuminated until the the Ground Hub resistor is removed. This test confirms the FAIL point for the neutral-to-ground resistance. DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 (909) 627-8178 Fax (909) 627-7449 DESCO EAST - One Colgate Way, Canton, MA 02021-1407 (781) 821-8370 Fax (781) 575-0172 Website: Desco.com 2014 DESCO INDUSTRIES, INC. TB-3049 Page 2 of 3 Employee Owned