- Why do I need a ground loop?
- Existing
- Systems
Connection Instructions Why do you need a ground loop?
The fact that most of the garages are made of metal with not very good waterproofing, as a result of which there is high humidity inside the room. At the same time, motorists use a powerful electric power tool - a welding machine, a compressor, heaters, etc. - to repair the machine. All these electrical appliances must be grounded otherwise if the current leakage to the housing, and especially if the work is in a humid environment, you may become a victim of electric shock. In the best case, everything can end with a trauma that will be remembered for your entire life. To once again not to expose your life to danger, it is recommended to make a grounding in the garage with your own hands, spending a little time and money on it. Below we will provide a simple instruction on how to properly ground the loop and what circuits it is better not to use.
Existing
systems So, first let's look briefly at how you can make the garage grounding yourself. There are several systems that are used today.
- TN-C.In this case, a phase and a combined conductor( zero to earth, PEN) are fed to the input shield. This PEN wire is already divided into PE and N at the input, which allows you to make a garage ground yourself. The disadvantage of this scheme is that, if the combined wire breaks, the phase will pass to all grounded electrical appliances. As a result, 220 volts will flow on all your metal lamps and power tools. One touch and the consequences can be fatal, so we do not recommend doing this alone.
- TN-S.More reliable grounding of the garage, however, it is unlikely to meet it in reality, becausefor this, the cooperative must stretch to consumers a separate N and PE wire from the substation to its own ASP.It is clear that it is not profitable to engage in this, therefore we reject such a scheme of the ground loop.
- TN-C-S.One of the safest systems, which is represented as follows: from the substation to the ASP of the cooperative, a combined PEN wire is pulled and a re-grounding is organized. Already from VRU to consumers there is a five-wire wire: 3 phases, zero and ground. Modern builders use this scheme of protection of electrical wiring for 380 Volt, but owners of old garages, most likely, will have to pay for the modernization of wiring. It's clear that car enthusiasts will not always agree on this either.
- TT.Well, the last scheme of the garage grounding is to make an individual circuit of several metal electrodes, dug in the ground next to the garage room. As you understand, this is the simplest and cheapest way to protect electrical wiring, which we will now talk about.
Below we will consider one of the options for installing the grounding in the garage with your own hands. The instruction with photo examples will help you to make a PE circuit yourself with minimal time and money.
Instruction for connecting
So, first, let's analyze the scheme of the correct grounding loop of the garage room.
It is mandatory to connect an RCD in the input shield, which will protect the wiring when leakage currents are detected. The residual current device is a very good assistant to the ground loop, becauseWhen an emergency situation occurs, it immediately turns off the electricity at the input.
As for the scheme of grounding of the garage on 220V, it can be executed either in the form of a triangle or in the form of a straight line, as shown below. Some electricians recommend to make a T-shaped protection circuit - 2 electrodes to drive in the corners from the front of the room and 2 electrodes to dig in the inspection pit. All 4 iron earthing switches are connected to each other and connected to the corresponding bus in the shield.
Electrodes can be represented by corners of metal, from 2 to 2.5 meters in length. The size of the corner must be at least 50 * 50 mm. If you decide to use a metal pipe to make the garage grounding by yourself, its diameter should be at least 32 mm, and the wall thickness is more than 3.5 mm.
Well, the last element of the circuit is a flexible wire that connects the underground structure to the ground bus. It is recommended to use a copper wire with a cross-section of at least 6 mm.kv.or aluminum with a cross section of more than 16 mm.kv.
Having prepared all materials, you can proceed to assembly of the contour. The first thing to do is dig in the electrodes in the soil. To do this, prepare small pits, depth of 50 cm, according to the chosen scheme, and dig through trenches between them to connect the grounding reinforcement. The most suitable distance between the electrodes is 1.2 meters. Digging pits according to the scheme of the grounding of the garage can be transferred to driving the corner into the ground. To do this, it is recommended to lower the lower end of the bullet in advance, then hammer the electrode with a sledgehammer so that it enters completely( the upper end must be half meter below the earth's surface).
The hammered corners are joined together by a metal strip, a width of at least 4 cm and a thickness of at least 5 mm. It is recommended to connect the elements of the circuit by welding, after preliminary cleaning the metal to a shine. 
For the convenience of connecting the wire to the corner, it is recommended to weld a bolt or a special terminal, as shown in the photo below. 
Lastly, a three-wire cable extends from the 220 volt shield to the garage and is connected to the ground to sockets and lights. You can clearly see the whole process in the video lessons below, which we strongly recommend you to read. 
With this instruction it is possible to easily make the garage grounding with your own hands. As you can see, everything is quite simple and does not take much time. If the garage room is located on the territory of the house, it is not necessary to make an individual protective circuit. It is more correct to initially make the grounding of a private house, then put a three-wire wire from the home shield to the garage.
It will be interesting to read:
- Calculator of grounding calculation
- Economical heating of garage by electricity
- How to make safe lighting in the basement
