System Sensor EOLR-1 End of Line Supervision Relay

The System Sensor EOLR-1 End of Line Supervision Relay is a compact power supervision relay designed to monitor auxiliary power supplied to 4-wire smoke detectors and other fire alarm devices. Featuring an epoxy-encapsulated SPST normally open relay, the System Sensor EOLR-1 provides dependable end-of-line supervision by monitoring power circuit integrity and reporting power loss to the fire alarm control panel. Therefore, it enhances life safety by ensuring critical detection devices remain continuously supervised.

System Sensor EOLR-1 Function

The System Sensor EOLR-1 is installed at the end of the power circuit serving 4-wire smoke detectors or other supervised devices. As a result, if power is interrupted anywhere along the circuit, the relay changes state and causes the fire alarm control panel to generate a trouble condition. In addition, the relay restores automatically once power is returned, eliminating the need for manual reset.

Reliable End-of-Line Power Supervision

The EOLR-1 is specifically designed to supervise auxiliary power circuits that cannot otherwise be monitored by conventional end-of-line resistors. Consequently, it provides continuous supervision for remote power supplies and 4-wire smoke detector circuits.

Multi-Voltage Operation

The System Sensor EOLR-1 operates over a wide 9–40 VDC input voltage range and is also compatible with 9–35 Vrms unfiltered full-wave rectified supplies. Therefore, it can be used with a broad range of commercial fire alarm control panels, auxiliary power supplies, and notification equipment. Furthermore, its low operating current minimizes additional load on supervised circuits.

Compact Epoxy-Encapsulated Design

The EOLR-1 features a fully epoxy-encapsulated housing with factory-installed pigtail leads for reliable operation in demanding environments. As a result, the relay is protected from vibration, moisture, and mechanical damage while allowing flexible mounting using the supplied screw or double-sided adhesive tape. Additionally, the compact design fits easily inside electrical enclosures or junction boxes.

Simple Installation

The System Sensor EOLR-1 is supplied with prewired leads, wire nuts, mounting hardware, and installation instructions. Consequently, installers can quickly integrate the relay into supervised fire alarm power circuits with minimal installation time. Its straightforward wiring configuration also simplifies future service and maintenance.

Technical Specifications

• Model: EOLR-1
• Type: End of Line Supervision Relay
• Manufacturer: System Sensor
• Relay Type: SPST Normally Open
• Operating Voltage:
  • 9–40 VDC
  • 9–35 Vrms (Full-Wave Rectified)
• Maximum Operating Current: 20 mA
• Contact Ratings:
  • 120 VAC: 0.5 A (Resistive)
  • 30 VDC: 3 A (Resistive)
• Operating Temperature: -22°F to 140°F (-30°C to 60°C)
• Storage Temperature: -40°F to 185°F (-40°C to 85°C)
• Humidity: 10–93% RH Non-Condensing
• Wire Length: 8 Inches Minimum
• Construction: Epoxy Encapsulated
• Mounting: Screw or Double-Sided Tape
• Application: Power Supervision for 4-Wire Smoke Detectors and Auxiliary Fire Alarm Power Supplies
• Warranty: 3 Years

Applications

The System Sensor EOLR-1 End of Line Supervision Relay is ideal for:

• 4-wire smoke detector circuits
• Auxiliary fire alarm power supplies
• Fire alarm control panels
• Commercial fire alarm systems
• Industrial fire protection systems
• Remote detector power supervision
• HVAC smoke detector installations
• Building life safety systems
• Power supervision applications
• Retrofit fire alarm upgrades

Reliable Power Supervision Solution

The System Sensor EOLR-1 End of Line Supervision Relay combines multi-voltage operation, compact epoxy-encapsulated construction, and dependable SPST relay performance in a simple supervision device.

EOLR-1