End of line resistor (EOLR) wiring is a technique used to monitor the integrity of the wiring and ensure that the circuit functions properly. This is especially important in systems that rely on a continuous current flow such as fire alarm systems, where the EOLR serves as an indicator for open circuits or other faults in the wiring.
What is an end of line resistor?
An end of line resistor is a component that is used to terminate a circuit, ensuring that the circuit is complete and secure. It is usually a high resistance value resistor, typically 4.7kΩ or 10kΩ, wired in parallel with the signal line. This means that if the circuit is open (or severed), the resistor provides a known value of resistance to the system.
EOLR wiring is used in various applications where it is necessary to monitor the integrity of the wiring. Some of the most common applications that use EOLR wiring include security systems, access control systems, and fire alarm systems.
Wiring a basic end of line resistor
To wire a basic end of line resistor, start by connecting one end of the resistor to the positive side of the circuit. Then, connect the other end of the resistor to the negative side of the circuit. Finally, connect the signal line to the point where the resistor and the negative side of the circuit meet.
If the circuit is closed and functioning correctly, the EOLR will not have any impact on the circuit, and the signal will flow freely. However, if the circuit is open or there is a fault in the wiring, the EOLR will provide a known resistance value, indicating the fault to the system.
Wiring a fire alarm system using EOLR
Fire alarm systems are critical systems that require reliable and accurate performance. EOLR wiring is a common method used in fire alarm systems to ensure that the system is functioning correctly.
When wiring a fire alarm system, the EOLR is usually wired in series with the initiating device such as smoke detectors, heat detectors, or manual call points. In this configuration, the EOLR is placed at the end of the line of devices, which is commonly referred to as the “last device on line”.
When all devices on the line are functioning correctly, the current flows freely, and the EOLR has no effect on the system. However, when a device is activated, the current is interrupted, and the EOLR provides a known resistance value to the control panel, indicating which device is in alarm.
Advantages of EOLR wiring
EOLR wiring offers several advantages over other wiring methods, including:
| Advantages | Description |
|---|---|
| Reliability | The use of EOLR wiring ensures that the circuit is complete and secure, reducing the risk of false alarms and ensuring that the system functions as designed. |
| Cost-effective | EOLR wiring is a cost-effective solution that requires only a few components, making it an attractive option for various applications. |
| Easy to install | The simple design of EOLR wiring makes it easy to install and maintain, reducing the risk of installation errors and simplifying system troubleshooting. |
Frequently Asked Questions
What is the purpose of an EOLR?
The purpose of an EOLR is to monitor the integrity of the wiring and ensure that the circuit functions properly. This is especially important in systems that rely on a continuous current flow such as fire alarm systems, where the EOLR serves as an indicator for open circuits or other faults in the wiring.
What is the value of an end of line resistor?
The value of an EOLR is usually a high resistance value resistor, typically 4.7kΩ or 10kΩ, wired in parallel with the signal line. This means that if the circuit is open (or severed), the resistor provides a known value of resistance to the system.
What are the advantages of EOLR wiring?
EOLR wiring offers several advantages over other wiring methods, including reliability, cost-effectiveness, and ease of installation.
Where is EOLR wiring commonly used?
EOLR wiring is commonly used in various applications where it is necessary to monitor the integrity of the wiring. Some of the most common applications that use EOLR wiring include security systems, access control systems, and fire alarm systems.
How do I wire a fire alarm system with EOLR?
To wire a fire alarm system with EOLR, the EOLR is usually wired in series with the initiating device such as smoke detectors, heat detectors, or manual call points. In this configuration, the EOLR is placed at the end of the line of devices, which is commonly referred to as the “last device on line”.
