Testing Your Ground – Easy Steps to Protect Your Investment
Having a solid grounding point for your QuikStor devices is crucial in protecting them. So how do you know if you have a good ground or not? Unfortunately adequately testing the ground rod resistance as well as the soil resistivity requires specialized equipment. A qualified electrician in your area should have this equipment and will know how to properly test the resistance at your equipment locations.
Q: When should I call an electrician?
A: If you experience a high number of surge board failures, then it is time to have your ground resistance tested at each grounding point.
Q: What do I do if my resistance is higher than what is listed in the section below?
A: Each facility and grounding bed is unique and poses their own challenges on how to overcome high resistance. The addition of a secondary grounding rod that is connected together (see below) can often cure the issue. Please discuss the right option for your facility with your local electrician.
More than you ever want to know about grounding:
A reliable equipment grounding system that connects all of your QuikStor Security components together must be kept at a safe reference potential. Since earth ground is considered to be at zero potential, making an electrical connection to earth is a logical choice. The earth grounding electrode should provide the lowest impedance connection possible to earth and maintain this reference at a low value. The objective is to dissipate the electrical surge away from you the main electrical device (keypad, UltraConverter, etc) and allow the surge to sufficiently flow the current to ground.
In the real world, however, the ground system typically does have resistance. All soil types have some measurable amount of resistance. The reality is that in comparison with metal conductors, soil is not a good conductor of electricity. It is important to understand that everything from the surge board grounding terminal to the grounding rod must provide minimal resistance and have solid connections. Resistances in the two to five ohm range are generally found suitable for commercial installations, such as self storage facilities.
The National Electrical Code requires that electrodes, i.e. grounding rods, shall have resistance to ground not to exceed 25 ohms and that if the resistance is not as low as 25 ohms, two or more electrodes connected in parallel shall be used. They should not be less than six feet apart.
NOTE: The 25 ohms value noted in the National Electrical Code applies to the maximum resistance for a single grounding rod. There is no implication that 25 ohms per se’ is a satisfactory level for a grounding system!
The most elaborate grounding system that can be designed may prove to be inadequate unless the connection of the system to the earth is adequate and has a low resistance. It follows, therefore, that the earth connection is one of the most important parts of the whole grounding system. For self storage applications, a resistance of less than 5 ohms is required to properly protect your QuikStor security system from failures arising from electrical surges.