How to Choose an Ethernet Surge Protector for Security Cameras and Network Equipment?

Damage of Lightning to CCTV Cameras and Equipment

Damage caused by lightning that stems from climate change has become a concern recently. As a result, lightning protection for surveillance equipment becomes crucial since it significantly reduces the damage rate of cameras and devices and saves money.

As surge protectors vary, you can choose the right one based on the requirement of your project. However, you may have encountered the following questions:

• What are clamping voltage, breakdown voltage, and max discharge voltage?
• What are UL 1449 and IEC 61643-11?
• Why is the device not working when connected to a surge protector?

We have introduced how a surge protector works in our last article Surge Protection for CCTV and Pro AV Equipment and its 4 Technologies. This time, we will help you understand all the specifications and select the best camera surge protector for your device.

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What Are the Specifications of CCTV Surge Protectors?

There are several different components in a surge protector. Unlike most electronic devices, there is no standard specification list for all surge protectors, while some similar concepts describe surge protectors differently. Here are some common terms used to describe surge protectors.

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Maximum Discharge Current/Voltage

The maximum amount of current/voltage that can be released to earth by the surge protector. If the current/voltage to release exceeds the maximum amount, the surge protector may be damaged.

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Breakdown Voltage & Clamping Voltage

Breakdown Voltage

The minimum voltage at which the surge protector is activated. When the voltage of the surge is higher than the breakdown voltage, the surge protector will operate. If the protector's breakdown voltage is lower than the device's working voltage, the device will not be able to operate due to the activation of the protector.

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Clamping Voltage

The concept of Clamping Voltage is close to Voltage Protection Rating (VPR) specified in UL1449. It describes the maximum voltage that can pass through the surge protector. When the protection is activated, it suppresses the voltage below the value so that the surge does not cause damage to the equipment.

In general, the breaking voltage and clamping voltage are closer to the operating voltage, the protection they provide will be better.

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Surge/Lightning Protection & ESD Protection

The duration and voltage vary when caused by different types of surge damage, while they all indicate the protection that a surge protector can provide.

Surge/Lighting Protection

Surges caused by lightning usually last longer, falling in the range of 1 to 1000 microseconds. The 8/20μs waveform is the most common type of lightning strike.

If the specification is "20kA (8/20μs) 10kV (8/20μs)," it means:

This surge protector can withstand instantaneous currents of up to 20,000A or voltages of up to 10,000V.

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ESD Protection

The contact of people and air with equipment can generate static electricity and cause damage to the equipment. Some surge protectors also indicate their protection against static discharge.

There are two types of ESD: contact and air. Their values are expressed as "30kV (contact)" or "30kV (air)."

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Response Time

Response time refers to the time when the surge protector detects a surge and operates, and generally, the shorter, the better. If the response time is too long, the surge may pass through the protector and cause damage to the device.

Because of the extremely fast speed of lightning, a surge protector's response time is measured in ns (1 Nanosecond = 0.001 Microseconds = 1 x 10-9 Seconds). The general specification of 1ns response time enables lightning to travel about 1.49m before the protector is activated, and the subsequent surge is blocked. Statistically, the response time is sufficient to protect your devices on a large scale.

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Insertion Loss

As information and power are transmitted, insertion loss will be caused; likewise, slight signal degradation is inevitable when the protector is connected to the cable. For example, the installation of an IP/PoE surge protector may slightly affect the bandwidth or even the transmission distance. Better protectors, undoubtedly, will cause lower insertion loss. Insertion loss is usually expressed in dB.

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Relevant Standards and Regulations

As surge protectors are concerned with the protection of property, information, and even your life, many standards have been published to verify that surge protectors are safe enough.

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International Electrotechnical Commission (IEC)

IEC 61000 is a series of tests designed to test the product's electromagnetic compatibility (EMC).

Tests related to lightning protection include:

• IEC 61000-4-2: Electrostatic Discharge Immunity Test
• IEC 61000-4-4: Electrical Fast Transient/Burst Immunity Test
• IEC 61000-4-5: Surge Immunity Test

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UL Solutions

As a product safety certification company, UL Solutions has established a wide range of regulations concerning safety when the product is damaged. It is considered an assurance when the electronics are regulated by UL Solutions, for they are guaranteed to be safe enough.

• UL1449: Surge Protective Devices
• UL497B: Protectors for Data Communications and Fire-Alarm Circuits

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International Protection Marking

Developed by IEC, also known as Ingress Protection Rating (IPR), it rates the degree of resistance of a mechanical casing or electrical enclosure against water and dust. If you use the surge protector outdoors, you may need one that has been tested for water and dust resistance.

Some common grades are recorded in the following chart.

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Solid Object Protection

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Liquid Ingress Protection

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How to Protect CCTV Cameras from Lightning?

Install Surge Protectors on Both Sides

Surge protectors should be installed on both sides of the equipment. While one protector only protects against currents from one side, the other side without the surge protector risks damage from the surge.

Generally, surge protectors have labels illustrating how they are connected. The cable end connects to the cables and the earth for grounding, preventing indirect lightning strikes. The equipment end connects to the equipment. They may also be labeled as a line-in or line-out side.

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Use Lightning Arresters for Server Rooms

Lightning surges may travel to the server room through the cables. Although buildings are grounded, surges passing by the cables can damage equipment in the server room. Large lightning arresters may be used as a protective measure while a lot of equipment is managed in the server room.

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Use the Surge Protector with a Suitable Size

When selecting a surge protector, consider the size that fits the equipment's case.

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Ground the Surge Protector

Grounding is the most crucial part. As the surge protector shields high-voltage energy, the energy has to be directed to the ground to protect the equipment. If the surge protector is not connected to the earth, it will have a shorter lifetime and can only provide less effective protection.

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How Far Can Lightning Strikes Influence?

Indirect lightning strikes can impact the equipment in a radius of 500m.

Buildings are usually earthed and equipped with lightning rods that can direct lightning surges underground. Cameras installed outside the building cannot be protected by the rod and thus need additional surge protection.

However, when directly struck by lightning, the surge protector cannot take the high-voltage energy, let alone protect the equipment. The chance of being struck by lightning is lower than winning the lottery, so it could be extremely good luck if lightning strikes your camera!

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How to Choose a Surge Protector for Security Cameras

Selecting a surge protector for analog cameras differs from selecting one for digital cameras. We will start with the analog cameras.

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Surge Protectors for Analog/HD Cameras

There are many different types of surge protectors for analog cameras. You should first identify your security camera system by answering the following questions:

• Does it transmit power over coaxial cables?
• Is there a PTZ camera, and does it require control signals?

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Different Models of Analog Camera Surge Protectors

• Transmit video only.
• Transmit video and power.
• Transmit video, power, and control signals.

A surge protector that transmits only signals cannot carry power. On the other hand, control signals are usually transmitted by twisted-pair cables to analog/HD cameras. Thus, a surge protector will need a twisted-pair contact to transmit control signals. It is important to understand your equipment to select the right protector.

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UTC for Control Signals

The use of UTC (Up to Coaxial) means the control signal is transmitted using coaxial cables. Cameras transmitting PTZ control signals using UTC will require a surge protector supporting UTC.

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Maximum Resolution

Before selecting the surge protector for analog cameras, please check the resolution supported by the protector; otherwise the equipment may not work correctly.

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IP/PoE Surge Protector for Cameras and Network Devices

IP/PoE surge protectors can be installed to protect network devices with an RJ45 interface, such as a router or network switch. Remember to check the required specification of your devices.

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Differences Between PoE & IP Camera Surge Protectors

IP camera surge protectors and PoE surge protectors cannot be used together. Although PoE devices are backward compatible with IP devices, the PoE version passes power through the cable and the clamping voltage is higher. These weak but constant currents may still damage the front-end IP cameras.

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Bandwidth Requirement

You must pick a surge protector that supports the corresponding bandwidth to transmit the camera's data. For example, you cannot transmit a 1000Mbps signal with a surge protector that only supports a 100Mbps bandwidth.

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PoE Standards

PoE devices use different standards and specifications. Standards of af/at/bt represent different power capabilities. Please ensure the surge protector is compatible with the PoE standards used by your PoE camera.

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Best Surge Protector for Security Cameras

SC&T's CCTV Surge Protection Series

• With a variety of models
• Designed for professional projects
• Highly rated by customers

SC&T has a wide range of CCTV and AV professional surge protectors. Click the link for more information!

Conclusion

Lightning itself is an unpredictable natural disaster. Surge protection cannot be achieved at 100% because the density of lightning surges varies from place to place. According to SC&T's experience, large-scale installation of surge protectors (e.g., regional road monitoring) can significantly reduce the damage rate, which can be seen by the decreased damage rate after installation.

However, there are still many regional and site-specific factors involved. In some of the cases we have worked on, the camera is connected to an anti-burglary wire mesh and is therefore more exposed to surges, which can enter the equipment on a large scale through the wire mesh and cause damage to the equipment. However, once the customer has installed a surge protector and grounded, the damage rate is reduced by 75-80%.

After finishing the article, I believe you have an idea when selecting the surge protector you need. If you have any questions about lightning arresters, please write to us.

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We have 20 years of experience in the ProAV/CCTV industry and have worked with brands around the world. We can diagnose your project type and provide you with the most suitable surge protector solution to solve any other problems you may encounter.