FGWilson Telecom Blog

Some advice in order to be more efficient in Preventive and Corrective Maintenance Services.

It’s no big secret nor mathematical formulae, but simple advice that could help daily tasks to be more efficient which, in the end, is what a tower site Maintenance Company constantly looks for.

First advice : Job Division.

People should specialize according to their skills and their command power. If they have the authority to command, chores will be performed

Second advice: Responsibility

Responsibility is the duty that each member of a Maintenance Team has of fulfilling their chores in order to achieve the best results. .

Third advice: Discipline

Discipline is to respect the agreement between the company and personnel.

The most efficient ways to establish discipline are:

1) Good managers at all levels.

2) Clear as possible agreements.

3) Fair sanctions.

Fourth advice: Command Unit

Workers should only receive orders from one boss or superior.  If two different bosses give commands to the same staff over the same service there will be discomfort, discipline will be compromised and the order will be altered.

Fifth advice: Leadership

To be able to persuade.

A person that commands others must have charisma in order to inspire others to do their jobs willingly.

A businessman must have those qualities in order to exercise leadership in his company and achieve his goals.

Sixth advice: Quality.

Quality is a commitment that a company or institution takes from its highest to its lowest level to do a good job and to keep doing it simply because it is more costly to correct it later on.

Seventh advice: The four letters of absolute quality

In a Radio base Maintenance Company there must be:

Q. Qualified and skilled labor

M. Modern and latest generation equipment

M. Materials, highest quality raw material.

M. Method, scientifically prepared, best technology available.

This is useful advice that leads to a good organization / administration and therefore to better efficiency.

I hope my experience will help you and that I was able to highlight the most important advice.

New technology in lightning protection.

INT is a company that researches and develops new technology related to renewable energy and environmental protection.

After analyzing different lightning damage statistics, our activity focused in the study of lightning, its effects and repercussions in home and industrial installations. During the investigation we discovered that current lightning rods, Franklin or PDC type, cannot control the intensity in lightning discharge during impact and they can generate more electromagnetic disturbances and high voltage tensions in the protection area they offer.

A paradigm is about to be broken. Why be protected against lightning by capturing its brutal discharge if we can’t control it? The best protection is defense, avoiding its formation in the protection zone or reducing the possibility of the lightning’s direct impact.

Protection for the future is already in the market.

Our first objective was to design a new concept in lightning protection. The first prototypes were verified in a high voltage laboratory and in real field. In 2002 they launched into the market the new model of CTS Deionizer lightning rod. Its protection policy breaks the paradigm of conventional FRANKLIN lightning rods.  This new lightning rod technology prevents lightning forming, avoiding formation and capture  of lightning in the structures to be protected by deionizing the electrostatic charge that is present in land structures. Its principle is simple, if we don’t create high voltage fields we will not generate ionization and by cause-effect we will avoid lightning forming and its

Transfer Switch Panels

The subject we will talk about today is Transfer Switch Panels. When an emergency generator is installed in order to provide power in case of a failure, a transfer switch is needed. It is designed to detect when there is a power failure, and then sends a signal to the generator for it to start, switch the load from utility to the generator and finally return the loade to utility when it has been re-established. In the image we can see a diagram of a Transfer Switch.

Fig. 9.9: Function of a Transfer Switch Panel

9.6.1 Intelligent Transfer Panel: This panel is designed to work with the Automatic Starting Control System in order to form an automatic system in case of failure from the general network. Its installation is very simple: only an interconnection of two control cables between the generator’s control panel and the transfer switch is needed.

The control system has two PLAQUES OF PRINTED CIRCUITS (P.C.I.), control switches, a state panel and automatic switches. The P.C.I. controls all circuits of failure detection in the network and surveillance. The Fuse Panel ATS of the P.C.I. contains all fuses for all functions of the P.C.I and its automatic switches. Both P.C.I.’s are mounted in the back part of the hinged folding door located in the front part of the transfer panel.

State Panel: This is installed in the front part of the door with the main control switch. This state panel has four lights as indicated on Figure 9.10. These are “Available Utility” (amber), “Utility with load” (green), “Generator with load” (red) and “Available Generator” (amber). To test the functioning of these lights, push the Lamp Testing Button located underneath and, if working properly, they will light on.

Controls: The main control switch has three positions:

AUTOMATIC SELECTOR – Normal setting for automatic functioning.

TEST WITHOUT LOAD – To test the generator without connecting charge.

TEST WITH LOAD – To test the generator with connected load. Besides the main control switch on the panel’s face, there is a three position maintenance switch to be used by service staff. In a "normal" position the Panel works normally. The other two positions allow the service staff to connect manually the load to the generator or to the general network. This switch is used when the P.C.I. is damaged.

Pos.     Description

1.            “Available Utility" light

2.            “Utility with Load" light

3.            “Generator with Load" light

4.            “Generator available" light

Fig. 9.10: Setting of the Transfer Switch Panel lights

WARNING:

·        Due to high voltage, the Inside Maintenance Switch should only be used by qualified technical staff.

How it works: The Transfer Switch works as following: When utility provides power to the load, the “Available Utility” and “Utilitywith Load” lights are on. These lights indicate that utility voltage level is above the P.C.I.’s MVS (network voltage adjustment level) and that the load is connected to utility. The MVS is calibrated by the manufacturer to the voltage corresponding to the disconnecting point of the three phases.

When the voltage of any of the utilities three phases falls below the MVS disconnecting level, the “Available Utility” light as well as the “Utility with Load” light are off and the Delay Start Timer is activated. This timer prevents false engine starts due to sudden fluctuations from the network supply. If the network supply has not been re-established by the elapsed delay time, the automatic network switch opens and a start signal is sent to the generator’s control panel.

Once the generator starts and is delivering power, the “Available Generator” light is on and the Transfer Delay Timer (AT) is activated. This timer allows the alternator to be stabilized before the Emergency Automatic Switch is locked. Once the AT Timer has calculated the delay time, and if the generator’s voltage is above the Generator’s Voltage Adjustment level, the emergency automatic switch is closed. This allows the generator to supply power to the load. At this moment the “Generator with load” light will turn on. When the utility supply is re-established above the MVS disconnection level, the “Available Utility” light will turn on and the IMT (Retransfer Delay Timer) will be activated. This timer allows some time to elapse in order to ensure that the utility supply is safe before transferring load again. If at any time the utility network voltage falls below the MVS during this period of time, the IMT will rearm and will not reactivate until the network voltage is above the MVS.

The best technology in Lightning Rods: CTS (Charge Transfer System) Lightning Rods

CTS (Charge Transfer System) Lightning Rods base their principle in air deionization . Their main objective is to avoid saturation of electrostatic charge between the earth installation and the atmosphere that surrounds us, peacefully compensating the difference of electric potential in the area during the first process of lightning formation.

CTS Lightning Rods

Basic Characteristics.

Known for facilitating electrostatic charge transfer between clouds and the earth before the second process of lightning formation, voiding the ionization phenomenon or crown effect in the structure or earth installation.

The Lightning Rod Terminal has two aluminum electrodes separated by a dielectric isolator. All of this is supported by a small stainless steel mast. Its shape is spherical and the system is connected in series between the earth and the surrounding atmosphere.

During the storm process a high tension field on earth proportional to the cloud’s charge and its gap’s distance to the floor is generated.

From a magnitude of the natural electric field on earth, the installation of the lightning rod equipment facilitates the charger’s transfer through the electric cable. These charges, despite their polarity, are located in the lightning rod’s bottom electrode that is connected to ground by the electric cable and situated at the top of the installation. 

Low resistance of the lightning rod’s bottom electrode at the top of the installation facilitates attraction of opposite charges in the upper electrode.  During this process of energy transfer, a small flow of current between the anode and the cathode happens internally in the lightning rod. .

The resulting effect generates a current discharge that leads to the installation’s grounding and is proportional to the cloud’s charge. During the storm’s maximum activity process, transfer values of up to 300 milliamps can be registered through the lightning rod’s installation cable.

The installation’s electrostatic charge is progressively compensated to earth as the potential difference between cloud and earth increases, neutralizing the effect ground point in 100% of all cases (Tracer or Leader).The lightning rod’s Terminal does not incorporate any radioactive source.

The effect of constantly dissipating the electric field from high tension in the protection zone ensures that the air around does not go over the rupture tension avoiding possible sparks, frying noise, radiofrequency, conducer’s vibrations and lightning strike.

The objective of the installation group is designed as Protection System Against Lightning (SPCR) where the main goal is to avoid the formation and discharge of lightning in the protection zone. The system is effective in a 100% of normal cases.

In an extreme case of coinciding lightning atmospheric electric activity, air ionization through solar radiation or solar storms and increase of atmospheric pollution due to volcano eruptions or tornados, the CTS Lightning Rod can saturate and not assume all the charge transfer; at that moment the CTS Lightning Rod can work as a capturing lightning rod producing at that instant a silent visual lightning, with no energy and without electromagnetic repercussions.

FG Wilson Power Plant recommended for Telecommunication Radio bases

For optimum Radio base functioning, it is necessary that it be working non-stop 24 hours a day.

How can we achieve this?  Good installation, correct maintenance, proper installation of grounding components, etc.

Today we will talk about one of the most important issues: Dimensioning the Generator.  For this, we need to know the Plant’s characteristics very well and that is the reason we give monthly options of FG Wilson Generators that we recommend for the Telecom Site. We know that its usefulness varies according to the Radio base needs; therefore having data from the most used Plants will make selection easier.

What is Telecommunications Preventive and Corrective Maintenance?

 

What is Telecommunications Preventive and Corrective Maintenance?

At this point it is very important to focus on what is an integral preventive maintenance service. We will define it as the following: “A group of calculated tasks and strategies designed and implemented by a specialized company to offer this type of service to Mobile Phone companies that have, as a result, a low impact in problems caused by damage, wear out or rupture of backup components of a Telecom site and where the cause is mainly the deficit in quality and quantity of the maintenance.

One of the main objectives of Preventive Maintenance is the reduction of Corrective Maintenances.

Advantages of Preventive Maintenance

• Significantly reduces the cost incurred by repairs and/or component replacements.
• Minimizes the Site’s time off air. It is more economic and efficient than corrective maintenance.
• Optimizes performance and longevity of the different components of a Telecommunication Site.
• With this type of maintenance, the number of satisfied clients in a Telecommunication company is always greater.

What is an Integral Preventive Maintenance?

We could define it as the maintenance that best suits a telecommunication company and which is also performed by just one company, therefore optimizing cost in tasks and routines that ought to be done at a Telecommunication Site. This company is responsible for:

• Maintenance of Generator/Power Plant and its corresponding Automatic Transfer Control Panel.  It should also provide the following:
• Transportation and qualified labor to fulfill the tasks.
  2- Provide all parts such as: filters, lubricants, refrigerants, fuses, terminals, etc.
• Provide and charge necessary fuel for optimum functioning of the power plant during power cuts from the commercial net.
• Maintenance of the AA system. The company should provide not only the labor but also the following:
       1- All the necessary cooling gas to keep the air conditioning equipment functioning correctly.
       2- All consumables such as, filters, thermostats, terminals and others.
• Maintenance of the Primary Power System (Commercial Net).The company providing the service should make sure that the Commercial Net is free and clear of obstacles and should also provide fuses of medium and low tension (as required).
• Infrastructure maintenance and site cleaning.
• Maintenance of Protection Systems and proper grounding.
• Maintenance of Beacon System.

The Importance of a good decision.

It is fundamental and almost critical to consider the qualifications of the company to be hired for Preventive and Corrective Maintenance. A correct decision will be based on the service being an investment not a cost. Sometimes the tendency is to consider that all companies providing services are the same, but that is not true.

ATI FG Wilson Transfer Switch

The Automatic Transfer Switch (ATS) ATI FG Wilson specifically designed for Telecom assures efficiency in the operation of Generators, putting up with the demands of the Telecom Radio towers.

When the commercial network fails, the ATS is responsible for instructing the Power Plant to start in order to energize the rectifiers, the air conditioners and the site transmission equipment so they can continue operating normally.

FG Wilson has designed a highly efficient and lasting Automatic Transfer Switch ATI designed to resist voltage spikes, atmospheric discharges, etc., keeping in mind the demands of a Telecommunication site.

In the link below, you will find more information and characteristics

http://www.sertec.com.py/telergia/telergia/informaciones/transfer_swich.htm

The new generation in “Power Wizard” Control Panels

It is worth remembering that the LPC2 analog Panel series that provides a power range of 10Kva to 20Kva was replaced by the new series called Power Wizard; for this power range the “Power Wizard 1” line, also known as DCP1 is used. This is a very simple and practical digital control panel; it has a digital display in which the electrical and mechanical parameters of the power plant are clearly visualized. This Power Wizard 1 Panel or DCP1 has been thoroughly tested in severe operational conditions (weather, external agents, salt, bangs, etc.) and as the obtained results were excellent, it is considered ideal for its use in Telecommunications. FG Wilson recommends it with an absolute warranty of safety and efficiency. The achievements were so good that the Power Wizard or DCP1 line will soon replace the excellent Series 2001 Control Panel. Additionally, there is the Power Wizard 2 and 3 or DCP2 and DCP3 that will replace the very efficient Panel Access 4000. The best one is the Power Wizard 4 or DCP4 that will replace the whole 6000 series of Control Panels used in parallel and synchronizing with other Power Plants, or with the Commercial Network or with both at the same time. Through the links you can access more information and characteristics of the Power Wizard.

http://www.sertec.com.py/telergia/telergia/informaciones/new_panel.html

http://www.sertec.com.py/telergia/telergia/informaciones/power_wizard1.html

Lightning rods, how they work, introduction and follow up. (Chapter II)

This is the second chapter of “Lightning, how it works, introduction and follow up”. It was provided by Angel Rodriguez (int@andorra.ad) whom we thank for this interesting article.   

Direct and Indirect effects on human beings 

Lightning is second leading cause of death in the United States, where the average is 139 deaths caused by floods annually, 87 by lightning, 82 by tornados and 27 by hurricanes.   

Each year hundreds of people die during the storm season. The most frequent cause is lightning strike close to the area where they were sheltering or due to direct impact (struck by lightning). During a storm, the atmosphere’s electric voltage can reach values of 1,000 to 1,000,000 Volts  between ionosphere and the earth.

Cases         Deaths        Situation

   1                   1                 On the beach

    1                   1                 Horseback  riding

    1                   1                 Fishing

    1                   10               In  Church

    1                   3                 Attending a Relative’s Burial

    1                   110             Traveling on a Plane

    2                   2                 Camping on the Mountains

    2                   4                 Taking a walk on the Countryside

    3                   9                 Fulfilling a National Duty

    3                   18               Working 

    4                   11               Being at home

    10                 23               Playing  Football

    11                 24               Sheltering from rain under a tree

    13                 20               Not specified

Struck by lightning Deaths: Studies of different accidents that have occurred during the past 5 years resulting in death caused by lightning, shows that in most cases people were under a tree, taking a walk or working out in the fields. Some of the lifeless bodies show signs of the effects of lightning. 

All or just part of the lightning discharge circulates through the body and in some cases clothing disappears. Death occurs because of the instant thermal and electric effects - in some cases the body is completely destroyed. Before impact, the victim feels a current that gives him/her goose     bumps; after that it is instantaneous, there is no time for suffering due to the speed of the strike.

 

Death caused by passing voltage: The impact of an indirect lightning strike generates strong passing voltage on the earth which affects people who are in a range of 120 meters from the center of the strike. People affected by passing voltage may suffer different lesions in their body; the damage caused is proportional to the intensity of the lightning during the impact. This can cause serious wounds and also death.

 

Physical Effects:   

• Cardiac arrest.

   

• Respiratory arrest.   

   

• Brain Injury.

   

• Skin burns. 

   

• Burst Eardrum.

   

• Retinal Injury. 

   

• Fall due to expansive electric waves. 

   

• Fall due to muscular contraction caused by a light passing voltage.       

   

• Lung and bone Injuries. 

   

• Post-traumatic stress.

 

 

The cause of these physical effects in people’s bodies appears directly on the earth or close to trees at the time of lightning impact, and appear especially because of the reaction of energy that transforms into Acoustic, electrochemical, thermal and electro dynamic effects. When lightning strikes on a metal structure or tip, “radiation” appears. These are the electromagnetic pulses that are generated during the electrical contact of lightning on any metallic element on earth. The radiated energy travels at light speed also generating a short reach expansive wave due to the sudden movement of the mass. Meanwhile the electromagnetic pulse spreads itself to large distances.  In this way, it electrically affects large geographic areas, reaching 300 km; on its trajectory it generates induction that transforms into dangerous  currents circulating through everything that protrudes from earth or is in contact with it. This reaction creates a difference in potential that can be represented by electric sparks with values higher than 15.000 Volts. The affected range varies proportionally according to the lightning’s intensity. Lightning discharges of more than 510 kA per microsecond have been measured, being on average 100 kA per second.

 

Direct and Indirect effects on installations:

The impact of lightning generates a wave of electricity on aerial cables that spreads through the network creating a high energy voltage.

 

Consequences:

Material destruction, premature aging of sensitive electronic components, disfunction of that equipment connected to the network that is in danger of fire.

VOLTAGE WAVE 1,2/50 µS                          CURRENT     WAVE 8/20 µS

 

During a lightning strike an induction in electrical tension and communication lines are generated. All sensitive electronic equipment that is within a range of 1.500 meters might be affected by a over voltage induction. 

Due to lightning strike intensity the ground cannot absorb all the energy discharged. This phenomenon might generate dangerous passing voltage on installations that are not prepared for this.

During a lightning strike, in less than 1 second, its energy circulates throughout the lightning rod in search of a low electrical resistance on earth. The electromagnetic pulse generated by the electrical contact of  the strike on the lightning rod is the result of the temporary magnetic field created by the energy circulating on the lightning discharge channel. The neutral current flows very quickly compared to the impedance of the discharge channel and the cloud’s electrical charge. The growing range of these current pulses varies proportionally to their intensity and speed according to each strike.

 

Electrical repercussions appearing during a lightning strike and affecting sensitive electronic equipment:

   

• Electrostatic charge

   

• Electromagnetic pulses

   

• Electrostatic pulses

   

• Earth currents

   

• Temporary over voltages
        - Resistive coupling
        - Inductive coupling.
        - Capacitive coupling.

It is estimated that during 2004 more than 40,000 accidents  will be reported to the insurance companies in Canada due to direct or indirect effects caused by lightning. Compensation will exceed forty million dollars.

Lightning kills in two ways: Directly: “struck by lightning” and indirectly: “by voltage contact     and fire”.

Lightning Rods, how they work, introduction and follow up. (Chapter I)

The effectiveness of a lightning protection system is one where the principle is to minimize or avoid direct lightning discharge on installations we want to protect, and to avoid all kinds of risks such as human death, accidents or fire caused by voltage differences or surges during the lightning strike.

Introduction

The lightning phenomenon: 

According to the world weather detection system, around 44,000 storms generating more than 8,000,000 lightning strikes happen during every second of every day around the world.

 

This is reference data because the evolution of weather is affecting lightning activity off season and even in winter or during snow storms.

 

A lightning strike is the electrical reaction caused by the saturation of electrostatic charges that have been generated by progressive accumulation of the electrical field between earth and cloud during the start of a typical storm. In a fraction of a second during the lightning discharge, the accumulated electrostatic energy becomes electromagnetic energy (the visible lightning strike and the sound interference), acoustic energy (thunder) and finally heat.

The lightning phenomenon is represented by an atmospheric electrical potential (10/45 kV). It is previously generated between two points of attraction of different polarization and equal potential in order to compensate for the saturation of electrostatic charge.

The lightning’s charge density is proportional to the electrostatic charge saturation of the area. The more density charge in the cloud, the bigger the risk of generating a leader in land and a lightning strike. The intensity in the lightning discharge is variable and will depend upon the critical moment of the air resistance break between the two reference points. The resistance of the exposed materials like land, rock, wood, iron, lightning installations and grounding will influence it, but will not limit the place of the strike, only its intensity. Lightning can transport an electric charge equivalent to 100 million ordinary bulbs in less than a second. The average measured charge per lightning strike is 20GW.

Once the lightning is formed, its trajectory can be chaotic, it will always predominate the power charged environments in the earths natural high voltage field. This electrical phenomenon is represented as an electrical shadow that will determine the elements that will be affected by the exchange of charges inside the natural high tension field.

Studies of the atmospheric electrical field around the earth determine that the charge distribution during the generation of the earth’s high tension field is not static but dynamic, by generating the leader in motion and different geographical points at the same time. The intensity and location of these electrical shadows can change radically and affect the sides and low parts of high buildings or structures.

Once the lightning is formed, the area of impact or the intensity of discharge cannot be guaranteed unless there is adequate protection.

Lightning causes great economic losses. 

According to references from 2002, lightning causes more than 5 billion dollars in economic losses to the United States alone.

Reference values for lightning :

 

• Voltage between cloud and an object on earth 1.               To1.000. KV
• Intensity of discharge                                                      5 a 300 KA
• di/dt                                                                    7.5kA/s to 500kA/s
• Frequency                                                                1 K Hz to 1 M Hz
• Time                                      10 microseconds to 100 milliseconds 
• Temperature higher than                               27,000 degrees Celcius 
• Propagation                                                    340 meters per second
• Electrostatic field/meter of elevation from land               10 kV

This data is only for your information since it is only proportional to the intensity of the cloud’s charge and the intensity of the lightning strike in each geographic zone.

The electrical phenomenon reverberated by a lightning impact, directly or indirectly during its strike, will vary according to the environment or installation that it finds in its path, where variable voltage values will appear depending upon material resistance, structure, situation and humidity of the ground grounding rod dissipation rate, absorption time of the physical land’s mineral compound, electrode’s crystallization state, etc.