Grounding and Protection of

Small Cells in 5G and 4G Networks

The deployment of small cells has
shifted in focus from coverage
Grounding
to large-scale densification. The purpose of this local ground electrode at the small cell is to provide
Operators are looking to increase • Public safety
the capacity in their LTE networks
• Low impedance ground for noise control
in more diverse locations,
to address rising consumer • A path for surge current dissipations from the power system
and enterprise use of mobile • Compliance to regulatory requirements
broadband. Many operators are • Suitable AC and telecommunications equipment ground
already planning hyperdense
• Lightning protection ground in very high lightning zones
networks in the 4G, and they
expect the trend to intensify The local AC ground electrode may be used for the purpose of grounding the small
with the migration to 5G. cell equipment if it exists. There can be concerns about the integrity of these existing
The deployment of small electrodes due to their age, poor resistance, corrosion, uncertainly about material
cells is expected to used, inadequate theft prevention and reliability of connection methods used.
increase exponentially.
There will be many instances when a new ground electrode will be required. This
The attractiveness of this poses challenges in built up areas for two main reasons. Cutting and re-instating
technology from a data network the ground surface can be costly and obtrusive. There are usually concerns about
availability point of view is damaging underground services like gas pipelines and AC power utility cables.
obvious. However, considerations
Several methods of grounding may be feasible.
for powering & grounding of
these small cells continue to be a
challenge for the industry.
nVent ERICO offers a range of
solutions for grounding and surge
protection of power supply to
small cells.

2 | nVent.com/ERICO
Grounding and Protection of
Small Cells in 5G and 4G Networks
VERTICAL DRIVEN ELECTRODES

Vertical electrodes are the least obtrusive, as they require less foot-print and are often the easiest to install, however when utilizing
these, the information available on buried services, near the electrodes needs to be known. The consequences of driving an electrode
into an essential service like power cable or gas pipe could be catastrophic. Many countries have services and records like “call before
you dig” to alleviate such risks.
Vertical driven electrodes also provide an effective means of reducing the ground resistance which will decrease with the depth
of the electrode.
Multiple electrodes can be joined using ground rod couplers, for example 1.5 m – 3.0 m (5 ft – 10 ft) lengths to greater depths of
4.5 m – 6.0 m (15 ft – 20 ft).

There are four types of vertically driven grounding systems

than can be considered for pole & street mounted antennas
in modern radio communication networks. These can be
used on sites with AC Main powering, DC Powering with or
without batteries and other powered sites.
Recommended configurations include:
1. Two copper bonded steel ground rods in a straight line
2. Three copper bonded steel ground rods in a triangular
formation with the triangle lengths of a minimum of three
Two Ground Rods in Line
electrodes length
3. Two or more electrodes at distance or one electrode apart Three Ground Rods in Triangle
installed at an angle of 45º forming an inverted V shape
4. One deep driven copper bonded ground rod

The conductors shall be a minimum of 2 AWG Solid copper

(USA), 16 mm2 stranded (Australia) or other sizes depending
on the country of application.
nVent ERICO Cadweld is the recommended connection
method for all underground systems for any
telecommunications installation. Where widespread rapid
deployments are required, and trained Cadweld installers
are not available across the sites to be deployed, the nVent Two Ground Rods Inverted V
ERICO hammerlock system is the recommended alternative.
Two or more in-line, coupled
ground rods

HORIZONTAL ELECTRODES

Micro-trenching or other horizontal trenching may be utilized Theft

to provide access to the small cell via fiber or copper wires. deterrent
composite
Horizontal electrodes may be a viable grounding option cable or
Micro Trench
provided it is practical to place them in the same trenches. Using tool like copper wire
Ditch Witch Pigtail to
For horizontal ground electrodes, the resistance improves Micro Trencher connect
with the length of the electrode and less so with the depth. to street
mounted
However, the depth may be the over-riding factor for electrode electronics
orientation due to practicality of where the electrode could be
laid, due to local legislation, due to mechanical considerations Copper
or due to the freeze depth in very cold climates. Bonded Steel
Conductor
CBSC 8mm,
10 mm or
12 mm

18" or
500 mm

nVent.com/ERICO | 3
Grounding and Protection of
Small Cells in 5G and 4G Networks
MESH ELECTRODES
Mesh electrodes are suited where deep driving
and trenching is not possible and the equipment is
mounted in a street cabinet, or there are existing
pavers at the ground level.
Theft Deterrent Composite A 600 mm x 600 mm (2 ft x 2 ft), 1200 mm x 1200 mm
cable or copper wire (6 ft x 6 ft) or larger mesh of copper coated steel is
18" or 500 mm
Pigtail to connect to street
below pavers used in these applications. All joints within the
mounted electronics
mesh are pre-welded and a pigtail can also be
pre-welded. The mesh can be placed in 50 mm
(2 inches) of nVent ERICO GEM25A or Quickfill
ground enhancement material to provide further
stability and consistency of ground resistance with
low ground impedance.

Steel wire mesh embedded in solidly molded ground enhancement material.

The table below shows the comparison of resistance values for the various types of grounding systems discussed here across
different soil resistivities. Soil resistivity is not discussed here but it is suffice to understand that in a uniform soil, the resistance
of the ground electrode is directly proportional to the resistivity of the soil, which is a characteristic of the local soil. In real life,
the soil resistivity will vary with depth and hence some examples in Table 1 show modelling results with varying soil resistivities.
While the modelling and calculations done in the table are at certain resistivity values, it is well understood that resistivity varies
significantly with location even in the same country, city or even town.
To get more use from this table, one can assume that the ground electrode resistance will vary proportionally with the soil
resistivity in a linear manner. For example, if the resistivity doubles then the resistance will double.

Ground Electrode Simulation Scenarios for Small Cells

Resistivity Resistivity
100 ohm-m 50 ohm-m
Resistivity, (5 ft Depth) (5 ft Depth)
50 ohm-m 50 ohm-m 50 ohm-m
(5 ft Depth) (5 ft – 10 ft (5 ft – 10 ft
Resistivity 25 ohm-m Depth) Depth)
50 ohm-m (5 ft – 10 ft 25 ohm-m 100 ohm-m
Scheme Grounding Scheme Uniform Depth) (10 ft – 15 ft) (10 ft – 15 ft)
1 Single Vertically Driven Ground Rod 5 ft or 1.5 m deep 29.0 33.3 47.7 30.1
2 Single Vertically Driven Ground Rod 10 ft or 3 m deep 16.5 10.3 19.9 18.4
3 Single Vertically Driven Ground Rod 20 ft or 6 m deep 11.8 6.8 12.1 15.3
4 Single Vertically Driven Ground Rod 5 ft or 1.5 m deep 9.2 5.1 7.4 13.1

3 Rods 8 ft, in equilateral triangle

5 7.0 4.7 8.7 8.1
formation, with 8 ft sides of triangle

Horizontal Electrode (say 35 mm2 wire, #2 wire or

6 13.3 11.9 23.4 14.3
similar) 0.5 m or 18" deep and 15 ft or 4.5 m long
Horizontal Electrode (say 35 mm2 wire, #2 wire or
7 12.4 10.9 21.2 13.4
similar) 1 mm or 36" deep and 15 ft or 4.5 m long

Prefabricated wire Mesh

8 20.3 18.4 36.1 21.4
600 mm x 600 mm (2 ft x 2 ft)

9 As above 1200 mm x 1200 mm 11.1 9.3 18.1 12.2

4 | nVent.com/ERICO
Grounding and Protection of
Small Cells in 5G and 4G Networks
GROUND POTENTIAL RISE CONSIDERATIONS
The densification of the network also means that in the modern telecommunications network, the installations are closer to the
public domain and often in densely populated areas. Examples of such infrastructure could include small cells, macro cells, fiber
cabinets and other facilities. Some of these facilities, when located in metropolitan areas, would be powered via the AC mains
from the local power supply network and would require a local telecommunications ground electrode and perhaps an additional
AC protective ground electrode.
Newer considerations, have to be given to ground potential rise that can occur at or near a telecommunication facility that is
close to power utility assets and near to other consumers. nVent can provide design assistance to model the ground potential
rise and associated step and touch voltages that could occur at the telecommunication facility.

COPPER THEFT CONSIDERATION

As many of the installations are located in public spaces and areas that may be prone to copper theft, consideration should be
given to the use of alternative materials to copper for use as conductors and pigtails.
Two commonly available alternatives used are:
• nVent ERICO Cu-Bond Round Conductor (Copper Bonded Steel Conductor, CBSC) complying with IEC 62561-2
with diameter of 8 mm – 10 mm (0.315 - 394 inches)
• nVent ERICO Cu-Bond Composite Conductor

The Alliance for Telecommunications Industry Solutions ATIS-0600037 Testing Guidelines for Copper Theft Deterrents in the
Telecom Industry, provides guidelines for testing of alternative conductors.

nVent ERICO Cu-Bond Round Conductor nVent ERICO Cu-Bond Composite Conductor

The Cu-Bond Round Conductor (Copper Bonded Steel Cu-Bond Composite Conductor is a bare concentric
Conductor, CBSC) is comprised of an electro-plated coating stranded conductor that consists of peripheral tinned
of copper deposited over a layer of nickel surrounding a steel copper plated steel which protects and conceals the
core. This process helps ensure a long-lasting molecular bond internal copper stranding.
between the copper layer and the steel. The conductor core
This conductor is ideal for exposed electrical grounding
consists of a low-carbon steel grade for improved flexibility in
applications where copper theft may occur due to its tinned
the field. The copper surface of the conductor provides high
outer strands. The conductor is difficult to cut with hand tools,
conductivity and corrosion-resistant properties.
but the copper core makes it easier to install than other theft
Features deterrent conductors. The outer stranding is magnetic, which
• Theft Deterrent: Due to its steel core, the conductor is very further deters thieves looking for copper. The CC5A05CB is
difficult to cut with hand tools suitable for telecommunications radio sites.

• Cost Effective: The cost of the conductor is minimized by Features

reducing the total amount of copper in the cable, because • Outer strands comprised of tinned copper-bonded steel for
the copper is bonded to a steel core theft deterrence and improved corrosion resistance
• Superior Corrosion Resistance: In comparison to other • Inner copper stranding is tinned for superior corrosion resistance
steel-based products, Cu-Bond Round Conductor provides
• Copper stranding inside of conductor increases conductivity
excellent application life of typically 30 – 40 years in most
and conductor flexibility
soil conditions
• Copper strands are hidden by outer tinned copper bonded
steel strands
• Suitable for direct burial applications

Cu Bond round Conductor Cu-Bond Composite Cable

nVent.com/ERICO | 5
Grounding and Protection of
Small Cells in 5G and 4G Networks
METAL POLE CABLE RETICULATION INTERNAL

nVent ERICO
Surge
Protection
Din Rail or
Outdoor Type

4 possible grounding arrangements

RRU

Power
Distribution
Two Ground Three Ground Two Ground Two or more
Rods in Line Rods in Triangle Rods Inverted V Ground Rods Deep

Power
Access

TWO GROUND RODS IN A LINE TWO GROUND RODS INVERTED V

Part Number Description Image Part Number Description Image

5/8" x 8 ft Copper Bonded 5/8" x 8 ft Copper Bonded
615880 615880
Ground Rod Ground Rod
5/8" x 10 ft Copper 5/8" x 10 ft Copper
615800 615800
Bonded Bonded
Conductor 2 AWG tinned copper or Conductor 2 AWG tinned copper or
Size 35 mm2 stranded copper Size 35 mm2 stranded copper

EHL58C1V1V Hammerlock – 2 hole EHL58C1V1V Hammerlock – 2 hole

THREE GROUNDS IN TRIANGLE TWO OR MORE GROUND RODS DEEP

Part Number Description Image Part Number Description Image

5/8" x 8 ft Copper Bonded 5/8" x 8 ft Copper Bonded
615880 615880
Ground Rod Ground Rod
5/8" x 10 ft Copper 5/8" x 10 ft Copper
615800 615800
Bonded Bonded
Conductor 2AWG tinned copper or Conductor 2 AWG tinned copper or
Size 35 mm2 stranded copper Size 35 mm2 stranded copper

EHL58C1V1V Hammerlock – 2 Hole EHL58C1V Hammerlock – 1 hole

Part Number Description Image CC58 Ground Rod Coupler

B13716 Ground Rod Driver

6 | nVent.com/ERICO
Grounding and Protection of
Small Cells in 5G and 4G Networks
GROUNDING OF POLE MOUNTED-ISOLATED LIGHTNING PROTECTION SYSTEM IN HIGH LIGHTNING ZONE

Air terminal

500 mm – 1000 mm Depending

on Standard Applicable
Isolated
mast cap
Upper
termination
Smart Lighting with voltage
stress control

Fiberglass
Isolated reinforced
Antenna and Small Cell and  ownconductor
d mast
Smart City Equipment

ISOMMB50
& FIXOBAND
stainless steel
mounting
nVent ERICO arrangement
ETMAGS Stainless steel
Grounding connector to conventional lightning
Standoff protection or grounding system
nVent ERICO Pipe
or Pole Bond

Ground Connection
nVent ERICO
Hammerlock or
Cadweld Oneshot Copper Grounding
Conductor or Copper
Bonded Steel
Conductor nVent ERICO
CBSC8 or LPC122

Ground Connection nVent

nVent ERICO ERICO Hammerlock or
Copper Bonded Cadweld Oneshot
Ground rod.
Various Sizes
nVent ERICO Copper Bonded
Ground rod. Various Sizes

nVent.com/ERICO | 7
Grounding and Protection of
Small Cells in 5G and 4G Networks

SURGE PROTECTION

nVent ERICO surge protective devices (SPDs) provide the ratings provided. Our SPDs with TD technology have been
option for traditional construction or nVent ERICO's patented designed to be unaffected by the AC overvoltages, while not
Transient Discriminating (TD) Technology. For example, the compromising the clamping performance. This provides
DT product line features traditional construction, while the them with the ability to survive extreme overvoltage
EDT product line utilizes TD technology. These product lines conditions and still be operational afterwards to protect
have been designed, independently tested and certified to your valuable equipment from subsequent surges and
the latest editions of both IEC61643-11 and UL1449 Ed4. This transients. This extends greatly the life expectancy of
provides the user of the peace of mind that the products will the SPD within the most extreme environments, saving
perform safely in application, and also perform to the claimed maintenance work and reducing operational costs.

8 | nVent.com/ERICO
Grounding and Protection of
Small Cells in 5G and 4G Networks
The secret to nVent ERICO’s Transient Discriminating
Technology is its active frequency discrimination circuit.
This patented device can discriminate between a temporary
over-voltage (TOV) condition and a very fast transient, which
is associated with lightning or switching-induced surges.
When the transient frequencies are detected, the patented
Quick-Switch within TD activates a robust protection
circuit that limits the incoming transient. The frequency
discriminating circuit that controls the Quick-Switch helps
ensure that the SPD device is immune to the effects of a
sustained 50 or 60 Hz TOV. This allows the device to keep
operating, in order to help provide safe and reliable transient
protection, even after an abnormal over-voltage condition
has occurred .
Effectively, TD Technology allows the SPD to have two
clamping levels – one well above the peak of a TOV (up to
twice its nominal AC voltage!), and the other much lower,
to effectively and swiftly clamp lightning transients. As the
explanatory illustration shows, this allows the TD circuit to still
remain operational after TOV events, thus continuing to clamp
transients and providing a much longer operational life. For
example, the IEC 61643-11 standard applies a test of 442 Vac
for two hours from Line to Neutral for SPDs intended to operate
at 230 Vac. While most SPDs fail safely during this test, nVent
ERICO’s EDT2 Series SPDs are unaffected by this stringent
test, and remain completely operational. The IEC 61643-11
standard calls this Withstand mode, as opposed to Safe Failure
mode. nVent ERICO SPDs that incorporate TD Technology are
especially recommended for any site where sustained over-
voltages are known to occur, and where failure of traditional
SPD technologies cannot be tolerated.

Traditional Technology Traditional Technology Response

Until replaced, further surges go unimpeded
straight to the equipment to be protected!
TD Technology Provides
Continued Protection - Thermal
Traditional SPD, at best, disconnects
safely during TOV event.
Even After Over-Voltages Disconnect

Typical Supply Problems Traditional SPD

voltage clamping
1. Transient 2. Substantial 1. Transient
Impulse Over-voltage Impulse

Active TD Technology TD Technology Solution

TD Technology clamps
TD Quick time after time!
Switch

Thermal
Disconnect TD technology
clamping

nVent.com/ERICO | 9
Grounding and Protection of
Small Cells in 5G and 4G Networks

nVent ERICO DT and EDT Range Surge

Protective Devices – 2 Mode

The above application shows the use of nVent ERICO DT230011 products being used
to protect small cells.
nVent products suitable for protection of small cells, depending on the country of
application, are shown below. It is expected that most small cells will be powered by nVent ERICO SES40P Range Surge
a single-phase power supply, and the listed products here are all single phase. Protective Devices – 3 Mode

Max Continuous
Imax , Max Discharge Operating Voltage, In, Nominal
Part Number Current Nominal Voltage Un Uc Discharge Current Protection Modes
Phase-Neutral
DT215011R 50kA 120V 150V 20kA
Neutral-Ground
Phase-Neutral
DT215020R 50kA 120V 150V 20kA
Phase-Ground
Phase-Neutral
DT230011R 50kA 240V 300V 20kA
Neutral-Ground
Phase-Neutral
DT230020R 50kA 240V 300V 20kA
Phase-Ground
Phase-Neutral
EDT215011R 50kA 120V 150V 20kA
Neutral-Ground
Phase-Neutral
EDT215020R 50kA 120V 150V 20kA
Phase-Ground
Phase-Neutral
EDT230011R 50kA 240V 300V 20kA
Neutral-Ground
Phase-Neutral
EDT230020R 50kA 240V 150V 20kA
Phase-Ground
Phase-Neutral
SES40P1201P 40kA 120V 150V 20kA Phase-Ground
Neutral-Ground
Phase-Neutral
SES40P2401P 40kA 240V 300V 20kA Phase-Ground
Neutral-Ground

10 | nVent.com/ERICO
Grounding and Protection of
Small Cells in 5G and 4G Networks
NVENT ERICO EXPERTISE

The nVent ERICO advantage is our approach to the complete HISTORY

Facility Electrical Protection Solution. Well designed and high
nVent ERICO engineers have been developing grounding &
quality Surge Protection is critical to a facility equipment’s
surge solutions for over 100 years. In 1903, the Electric Railway
reliable operation, however it is only part of the solution.
Improvement Company (ERICO®) was created to supply
nVent ERICO therefore offers the complete range and power bonds, signal bonds and related welding equipment to
expertise in grounding, bonding, surge and lightning protection, railroads, mining and street railway industries.
providing the complete solution worldwide and across
They are experts in designing products to achieve a variety
applications including Commercial, Industrial, Telecom, Utility
of global certifications including, but not limited to,
and Railway. Our service and expertise encompasses more
UL 1449 Ed. 4 and IEC 61643-11. In addition to this, nVent
than just the product.
ERICO engineers have designed unique, innovative surge
technologies like Transient Discriminating (TD) Technology
PRODUCT TESTING and high-performance surge filters. Our engineers have
developed surge products and technologies protecting a
To effectively meet market requirements and ensure
variety of industry-specific needs with some examples being:
our products are designed and tested to the highest of
rail signaling, photovoltaics, telecommunications, LED lighting,
performance standards, nVent ERICO has invested in state of
and wind turbines.
the art testing equipment that is able to:
• S
 upport application testing for clients – to ensure your
equipment is adequately protected SEMINARS AND SITE AUDITS
• Participate in the UL Client Test Data Program. Each year nVent ERICO conducts hundreds of seminars in
• Support competitive product testing numerous countries around the world, educating specifiers,
engineers, and installers on Facility Electrical Protection.
• Test and evaluate to a range of mechanical, electrical and
environmental requirements

nVent.com/ERICO | 11
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©2020 nVent. All nVent marks and logos are owned or licensed by nVent Services GmbH or its affiliates. All other trademarks are the property of their respective owners.
nVent reserves the right to change specifications without notice. ERICO-CAT-H86009-TelecomSmallCell-UKEN-2009