Functional Grounding Device for a Plasma Cutting Machine in the Moscow Region

To arrange the workplace and provide safe operation of the plasma cutting machine by the personnel, you have to make a series of preparations. An essential issue is the presence of a functional grounding device meeting several requirements.

 Functional grounding for the plasma cutting machine

Further, we are going to consider which requirements have to be taken into account and what solution was offered by the ZANDZ Technical Center.


Initial data:

  • facility: plasma cutting machine;

  • region: Moscow Region;

  • soil resistivity: 100 Ohm*m.



  • to calculate functional grounding arrangement with the resistance not more than 1 Ohm;

  • the distance to the machine should not be more than 6 m.



Functional grounding arrangement for the plasma cutting machine is made in compliance with:


A set of measures to ensure the requirements to the functional grounding system for the plasma cutting machine is represented by the following solutions:

  • installation of 5 x 27 m deep vertical grounding arrangements combined with a horizontal grounding arrangement;

  • the distance between the electrodes is 30 m;

  • deepening is at least 0.5 to 0.7 m;

  • 27 m copper-plated steel electrodes are used as a vertical grounding arrangement (18 pcs x 1.5 m each);

  • the copper-plated steel strip with a cross-section 30 x 4 mm, combining all vertical electrodes, is used as a horizontal ground electrode;

  • the distance from the grounding arrangement to the machine is not more than 6 m.


Ground terminal resistance calculation:

Vertical electrode resistance:

Calculation of resistance for the vertical grounding arrangement

Верт - Vert
Ом - Ohm

where    ρ ρeq – is equivalent soil resistivity, 100 Ohm·m;

L – is vertical electrode length, 27 m;

d – is diameter of the vertical electrode, 0.014 m;

T – is deepening, i.e. the distance from the ground surface to the ground electrode, 14 m;

Grounding arrangement deepening

м - m

where     t  – is deepening of the electrode top, 0.5 m


Horizontal electrode resistance:

Resistance calculation for the horizontal grounding arrangement

Гор - Hor
Ом - Ohm

where    ρ – is soil resistivity, 100 Ohm·m;

b - is horizontal electrode width, 0.03 m;

h - is horizontal electrode depth, 0.5 m;

Lhor – is horizontal electrode length, 120 m..


Electrical impedance of the grounding arrangement:

Calculation of impedance of the grounding arrangement

Ом - Ohm

where n – is a number of sets, vertical grounding arrangements - 5 pcs, horizontal grounding arrangement - 1 pc;

Kutil – is utilization rate, 0.7.

Estimated resistance of the functional grounding arrangement is 0,96 Ohm, which is less than the required value of 1 Ohm.


Design of the grounding arrangement is shown in Fig. 1.

Электрод L=27 м, D=14 мм - Electrode L = 27 m, D = 14 mm
Полоса стальная омедненная сечением 30 х 4 мм - Steel copper-plated bar with cross-section 30 x 4 mm

Figure 1. Equipment layout.

The list of necessary materials is given in Table 1.

Table 1. List of needed materials.

Part number Name Quantity, pcs. Unit weight, kg. Note
1. GL-11075-50 GALMAR Copper-plated strip (30 * 4 mm / S 120 mm²; 50-meter strip bundle) 3 0,98 Weight per 1 m
2. ZZ-001-065 ZANDZ Copper-plated threaded grounding rod (D14; 1.5 m) 90 2,00  
3. ZZ-002-061 ZANDZ Threaded coupling 86 0,08  
4. ZZ-003-061 ZANDZ Termination 5 0,07  
5. ZZ-004-060 ZANDZ Guide head for jackhammer attachment 18 0,09  
6. ZZ-005-064 ZANDZ Conductor connection terminal (up to 40 mm) 9 0,312  
7. ZZ-006-000 ZANDZ Conductive grease 9 0,10  
8. ZZ-007-030 ZANDZ Waterproofing tape 3 0,40  
9. ZZ-008-000 ZANDZ Attachment to the hammer (SDS max) 1 0,50  

Do you need to calculate the functional grounding arrangement for the plasma cutting machine? Please contact the ZANDZ Technical Center!

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