# Grounding of a CCTV System for Railroad Stations

A CCTV system is an essential part of providing security, safety of material assets and control over the operation of the railroad station personnel. To ensure proper operation of the equipment, a reliable grounding system is required. The ZANDZ Technical Center received a request to calculate the grounding for the CCTV system for railroad stations. Let us continue with more detailed review of our offered solution.

Calculation of Grounding of a CCTV System for Railroad Stations

Facility: a CCTV system for railroad stations

Task: to perform calculations for grounding of the CCTV system for railroad stations

Solutions to meet the requirements to the grounding system for the CCTV system for railroad stations:

1. Grounding is made in accordance with the 7th edition of the Electrical Installations Code.
2. Grounding arrangement (GA) is necessary to do with a resistance of not exceeding 4 ohms.
3. The soil resistivity accepted for calculations is 80 Ohm * m.
4. Stairs and handrails are connected by using clamp GL-11514.
5. Three vertical steel copper-coated electrodes 9 m long are used as grounding electrodes. The copper-plated steel strip with a cross-section of 30 x 4 mm, combining all vertical electrodes, is used as a horizontal ground electrode. The distance to the facility foundation is at least 1 m. Strip deepening is 0.5 to 0.7 m.
6. Connection to the grounding arrangement is made through clamps ZZ-005-064.

Ground terminal resistance calculation:

Rверт. - Rver
Rгор1 - Rhor1
Rзу - Rga
Ом - Ohm

The design resistance of the grounding arrangement is 3,5 ohms.

Figure 1 shows hardware layout.
Table 1 includes the list of required hardware and materials.

Figure 1. Hardware layout for the grounding of the CCTV system for railroad stations.

Вертикальный электрод длиной 9 м - Vertical electrode of 9 m long
Полоса 30х4 мм - Strip 30 x 4 mm

Table 1. List of material requirements.

 Item # Part number Product Quantity, pcs. 1. ZZ-001-065 ZANDZ Copper-plated threaded grounding rod (D14; 1.5 m) 18 2. ZZ-002-061 ZANDZ Threaded coupling 16 3. ZZ-003-061 ZANDZ Termination 3 4. ZZ-004-060 ZANDZ Guide head for jackhammer attachment 4 5. ZZ-006-000 ZANDZ Conductive grease 2 6. ZZ-008-000 ZANDZ Attachment to the hammer (SDS max) 1 7. ZZ-005-064 ZANDZ Conductor connection terminal (up to 40 mm) 3 8. ZZ-007-030 ZANDZ Waterproofing tape 1 9. GL-11075-20 GALMAR Copper-plated strip (30*4 mm/ S 120 mm²; 20-meter strip bundle) 1 10. ZZ-500-105 ZANDZ Ground cable (5 m; S25; single-wire; with a tip for bolt D8) 1

Do you have any questions about lightning protection of the CCTV system or other facilities? Please, contact the ZANDZ Technical Center!

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