Everything you need to know about Extra-Low Voltage (ELV) Systems
Oct 25, 2019

What are Extra-Low Voltage Systems (ELV)?

Extra-Low Voltage means the voltage of electricity supply is in a range that is low enough that it does not carry any high risk of any high voltage electrical shock(s).

The range of voltage that can be classified as Extra-Low Voltage is alternating current not exceeding 50 V AC and direct current not exceeding 120 V DC (ripple free). This is based on the standards as per EN 61558 or BS 7671.

Therefore, Extra-Low Voltage Systems are any electrical systems that can operate on a low voltage with the voltage criteria as per above.

In this article, we are going to share more about different components of ELV systems.

Components of ELV Systems

Closed Circuit Television System (CCTV)

Closed circuit television, also more commonly known as CCTV, is made up of a network of cameras and recording systems that are connected to each other. This system would be classified as a ‘closed’ system as the system operates independently, unless it’s part of an ELV integrated system. A CCTV system is an effective way to monitor and secure any sensitive area(s).

Currently, cameras can be connected either wired or wireless to a CCTV system. CCTVs are an effective deterrence to any threats or area(s) that require constant offsite monitoring.

The key points in installing CCTV cameras is the positioning of the camera, to ensure that the camera can monitor the required area in its scope of view as well as the clarity of the video footage to ensure usability of the footage if necessary.

Access Control System – ACS

Access control systems are a key feature of any security system hub that can secure, monitor and manage the access of staff in any type of building. With this system, staff can either be given access cards or using fingerprints(biometric), they are able to be granted access to various areas of the premises.

Nowadays, these systems ‘speak’ to each other wirelessly and usually connected to the local area network to reduce hard wiring cost and flexibility of the positioning of the system itself. At times, the access control system might be a part of a bigger integrated ELV system which allows central control of multiple different systems.

Public Address and General Alarm System – PAGA

A public address system is a system that allows an amplification of your voice through microphones and loudspeakers. Its purpose is to enhance the volume of human voice or any other sound for that matter.

The general alarm system allows remote control of alarms and flashing lights(beacons).

Combined, this system would serve a general use of relaying information or be used in the case of any emergency evacuations.

LAN and Telephone System

LAN stands for local-area network and is basically an interconnected computer network that usually covers a small area. This network of computer/devices can be connected to each other via physical wires called LAN cables or wirelessly (radio waves).

A telephone system is a group of interconnected telephones connected either via telephone lines or via LAN cables which then communicate using ‘Voice over Internet Protocol’ or in short VoIP.

Trunk Radio System – TRS

A trunk radio system is a system whereby all available radio channels are placed in one single pool. When for example person A requires to transmit, a channel is automatically picked from the pool and used for person A’s transmission. Once the transmission is completed, the channel that person A was using will be placed back into the pool for others to use.

This system is highly beneficial as radio channels are limited by nature as for example, if all radio channels are taken up, we can’t physically or manually ‘create’ new channels. By using a trunk radio system, it’s more efficient in a sense there is a higher chance a user will get access to an available channel when required.

Fence Intrusion Detection System – FIDS

A fence intrusion detection system or FIDS for short is a security system whereby the key purpose of this system is to be able to detect any breaches that occur on any perimeter fences.

There are multiple sensors installed on different parts of the fence so whenever an intrusion is detected in a certain fenced area, if there is a CCTV nearby, the security personnel would be able to angle the CCTV to view the intrusion if possible. If necessary, a physical check on the fence is needed as well to ensure the security and integrity of the perimeter.

Master Clock System – MCS

A master clock system is an interconnected system of clocks whereby slave clocks would take reference of time from a reference clock, also known as a master clock. These slave clocks would synchronize their time with the master clock. In this way, the time across both the master and slave clocks would be the same.

The use of master clock systems can be used in a variety of industries such as for the IT sector and military or anywhere that requires an extremely high degree of time accuracy.


Now that you understand more about ELV systems and their various components, Supermec provides ELV system integration services for the telecommunications, security, surveillance and oil & gas industries.

We have a team of highly experienced engineers and technicians who would be able to assist you in any challenging system integration issues.

Our service is that we can design, supply and install full ELV integrated systems, complete with detailed testing and following the actual site condition to ensure full functionality before handing over the project.

Due to our experience in installing explosion proof systems, we are well versed in working and installing ELV systems in hazardous environments.

Contact us at a time of your convenience at or +65 68619522 to find out more about how we can assist you with any extra-low voltage system integration matters.