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Are You Likely To Get Electric Shock From TV Antenna/ Sat Cable?
Perhaps, you are seeking to splice the coax cable that feeds your satellite receiver or TV. But before you will do that you would love to know if you are at risk of an electric shock or if it’s even safe to do that in the first place. Read this blog and find out all you need to know concerning the subject.
Before we go any further with this discussion, you need to know that your safety and that of others is not to be compromised at any time. Therefore, before you cut into any cable whether it’s for your TV or any other thing, confirm if it is live and do well to shut off the electricity accordingly as a safety precaution. You can go with a qualified aerial installer in St.Helens or electrician if you cannot adopt these basic procedures. I would not be responsible for any damage, injury, or loss that may happen from how this content may be interpreted.
Do Radio/TV Antenna Cables Carry Any Current?
Satellite dishes and TV aerials by their very nature are current conductors. A TV antenna will attract radio-waves within the surrounding atmosphere before transferring those waves to the cable that is connected to your TV. The signal which is transmitted along the cable is an A.C. electricity, which is higher than what is coming from your mains supply in terms of frequency. Well, that shouldn’t discourage your from cutting into your TV cable since the induced voltage on a TV antenna’s cable is actually low, extremely low. To explain the concept, a 60dBµV TV signal level is equivalent to a voltage 1mV. This is one volt divided into one thousand places. A fraction that has a negligible effect and harmless if you were to touch it with your bare hands. Even when you are privy to a TV signal as strong as 80dBµV, that accurately translates to 10mV. A fraction of a 100 volts. Your chances of getting any signal strength greater than 80dBµV are very slim, just in case you are afraid the voltage may get a little higher. Before you can get anything higher, you may have to overload your TV tuner, and that could downgrade the quality of your signals.
Systems with Masthead Amp/ Sky Remote Eyes/ Line Power
It’s common with specific TV antennas to get a direct current line power delivered simultaneously with the signal through the coaxial cable. Common instances of this can be seen in power supply units that provide power for masthead amplifier as well as line power coming from sky box or any other thing that could power any line powered amplifier coupled with remote eyes that let you manage your equipment from somewhere else. In such instances, expect a little quantity of current to flow down the coaxial cable. Many masthead amplifiers have power units that ranges between 5 and 12 DC, while some others range between 18 and 24 DC. A lot of Sky playback, remote systems are within 9 to 12V DC.
Do Satellite Dish Cables Carry Any Current?
TV antennas and satellite dishes work similarly, they pick signals that have been beamed to earth from space, delivering the signals to your satellite receiver. Usually, this could be in the form of Freesat/Sky box or a TV that comes with a satellite television tuner, integrated. In the aspect of current, what sets a satellite apart is that they receive their signals at low levels before using their LNB to amplify the signal, and eventually sending it to the satellite receiver. To accomplish this, a steady DC voltage has to be supplied by the receiver of the satellite to the LNB to keep it powered. Normally, it is around 13V DC, while switching LNBs such as Universal Quad use 18V for switching between vertical and horizontal polarised signals. While this is largely greater than what is obtainable with Radio/TV cables, it’s still lower than a voltage that can result to any harm. That is no indication that you are not going to feel anything. Although I don’t subscribe to this, I have worked with someone who puts cable in his mouth as a way of knowing if the cable is connected or not.
Whenever you are connecting a satellite dish cable and you feel any current, check around you, as it is most likely because you are in contact with a metal pole or you are using a metallic ladder. You must have also recognised that when it is wet, the shock sensation seems to increase. While this might not bring you any serious harm, it could make you jump or even fall off from your ladder. In such scenarios, you are advised to disconnect the satellite cables from its receiver or turn off the receiver completely, so that current will not be passed to the dish as you work.
Communal TV Systems
A communal TV system differs from a conventional TV system, since the system may be servicing hundreds of flats that may be feeding hundreds of connected TV equipment. When you put all these together, considering all the various amplifiers along with the accumulative effect of some of the equipment used, you might have a voltage buildup across the cables. While this may not amount to a voltage value that can cause you any harm, you are advised not to take this factor for granted. Any TV system that serves more than one dwelling should be connected to earth due to safety. It is good to also note that when you are working on TV systems, powering down equipment or disconnecting cables, several residents may come shouting at you that their TV channels are no longer working. They will even blame you for the development. To resolve such issues, just kindly ask them to tune again.
CAI – 6 Pcs of AV Equipment Disclaimer
The CAI’s standard for electrical safety within domestic settings is being safe when as many as five pieces of equipment connects to your television system. If the equipment are more than five, the systems should have earth connection, or customer ought to be enlightened of the situation while a disclaimer would suffice for waiving off any liabilities or installer parts. What this implies is that, when you have six or more AV equipment connected in your system, there could be a possible current build up that may result in injury should you ever come in direct contact with it. By the way, this is not some kind of regulation because I haven’t seen any company that has applied the same standard for domestic owners. They only resort to such measures to avoid any legal liability. I recommend you reach out to them for updated information because things may have changed during the time you are reading this.
Electrical Shock of Up To 50V Still within Safety brackets (Not My Words)
It’s believed a human being can withstand about 50V without experiencing any harm or injury. That is why a lot of these systems operate beneath that capacity. Systems such as Power over Ethernet use between 24 and 48V, your telephone line ring circuit uses 50V. I didn’t make this figure up, experts were the ones that came to the conclusion of the 50V safety reference.
Fault Conditions/Poor Electrical Installation May Be Responsible For High Currents
In instances where there are faults, it’s possible to have high current/voltage on the cable that serves your satellite dish or TV aerial. The old-fashioned cathode ray tube TV has up to 25000V within it. In most occasions they lack any earth connection in the mains. The antenna is the only metallic piece that will be exposed to this high voltage, since it does not have any metallic body parts. And it can have high voltage if there is a fault in the TV. Thankfully, the trending OLED/LED/LCD TVs do not produce voltages that are close to that of the CRT TVs.
Poor electrical installation could also be responsible for causing high voltage along the coaxial TV cable. However, this is an unlikely scenario. Unless you are still using the old-fashioned electrical installations. For instance, installers are not meant to bypass fuse. It’s unsafe. That’s another reason to be thankful for modern technology, as many new systems make use of MCBs and RCDs which will cut the power supply off if anything is suspected to be unsafe.
Safety Measures That You Can Take
I’ve referenced the worst scenarios for writing this post, just because I am very concerned about your safety. I don’t want you to come back and blame me for an accident that may occur while you are working. Go through the disclaimer in the beginning of the post again. With all of these in mind, you can also adopt some safety measures.