08.07.15 , , , ,
When planning grounding, many people still imagine many hours of excavation of trenches, welding works and energy-sapping driving angles into the soil. However, the time of this method of grounding has been gone long time ago. It is possible to make grounding for a single-family house or summer cottages, spending a minimum of time and money thanks to ZANDZ modular grounding system.
We offer you to consider the queston of organizing grounding for a country house on a real example!
Place: Novosibirsk region.
Facility: suburban residential one-storey house.
Soil at the site: clay.
Soil resistivity: 60 ohm / m
Power supply: Three-phase system, voltage 380 V.
Connect the protective grounding (more details on all types of grounding- on a separate page).
In order to determine the required ground resistance, we will address to EIC, edition 7. Chapter 1.7
The object of the protective grounding installation is a single-family house. In accordance with p. 1.7.103, ground electrode spreading resistance of each of the repeated groundings should not be greater than 30 ohm at the line voltage of 380 V of the three-phase power supply or 220 V of a single-phase power source.
The set of measures to ensure the necessary requirements for the grounding device is represented by the following solutions:
1) installation of one vertical electrode 6 m long of four pind 1.5 m long
of ZANDZ ZZ-6 kit, successively mounted into one point (20 cm of the last pin length must be left on the surface for mounting the clamp);
2) connection of the ground electrode with the grounding conductor ZZ-500-103 using the included clamp;
3) connection of the ground conductor to the electric board
Calculation of grounding device resistance:
Vertical electrode resistance:
Where p - soil resistivity, ohm-m;
L - vertical electrode length, m;
d - vertical electrode diameter, m;
T - burial - the distance from the ground surface to the ground electrode, m;
Where t - deepening of the electrode top, m
Grounding device impedance:
Where n - number of kits;
kисп - coefficient of use;
The design resistance of the grounding device is 11.39 ohm, which is less than the desired value on 30 ohm.
The list of required material is given in Table 1.
Table 1 – List of materials demand
4. Installation order
- hammer hand tool weighing 300 - 1500 gr: sledgehammer or heavy hammer;
- two wrenches or two pliers (to tighten the clamp bolts).
Sealing sleeves made of stainless steel are out on the pins for easy transportation. Before installing the sleeves must be removed.
Нагель- driving head
Штырь - rod
Втулка - sleeve
Герметик - sealant
Зажим - clamp
Штырь - rod
- Put the driving head into the pin hole.
- Drive the pin into the soil, hammering the driving head.
- Remove the driving head and put on a sleeve on the mounted pin ( with the wide part down).
- Insert the next pin with its pointed side to the mounted pin with the sleeve on. The connection will be pressed indipendently during installation.
- Repeat steps 1-4 until getting the desired depth of the ground electrode. The last pin must be left at 20 cm above the ground. The sleeve is not put on the last buried pin.
- Fix the clamp to connect the ground conductor, and having connected the conductor ZZ-500-103 itself, tighten the clamp screws with a maximum force.
- Put plenty of sealant into the pin hole to prevent getting of moisture
5. Installation video
The installation was carried out in the summer of 2014. The total time spent to unload equipment from the car and installation was not more than 30 minutes.
6. Grounding connection scheme
Комплект заземления – grounding kit
Освещение - lighting
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