Fire Alarm System Guide to Trouble Shooting – Introduction

Thomas Richards Project Sales Executive, Fire-SP

In the Canadian fire alarm industry, there is a document for almost everything. CAN/ULC-S536 provides technicians with instructions on inspecting and testing fire alarm systems, CAN/ULC-S537 covers the verification of fire alarm installations, and CAN/ULC-S524 details fire alarm system installations. These three standards are referenced daily by technicians across Canada, essentially serving as a "how-to guide" for fire alarm work.

But what about troubleshooting? Where is the guide for that? Many of us have responded to a late-afternoon service call for a trouble condition and thought, "If only I had step-by-step instructions to locate this ground fault."

To fill this gap, the Canadian Fire Alarm Association (CFAA) is creating a "Guide to Troubleshooting" series for publication in the CFAA Journal. This series will highlight common system issues and provide a step-by-step guide for investigating and repairing these impairments.

It’s worth noting that fire alarm systems are becoming more complex, with each model and manufacturer varying slightly. Therefore, most of this series will focus on troubleshooting conventional-type circuits. However, the basic troubleshooting skills covered will provide a foundation applicable to all types of systems.

Before you grab your toolkit and tell dispatch to send you to the next ground fault call, let’s start with the basics.

Fire Alarm Systems and Basic Electrical Principles

Fire alarm systems operate on the basic principles of electricity and Ohm's Law. It’s essential to understand these principles and how fire alarm systems are designed to function to apply the troubleshooting techniques described in this series.

Steps in Troubleshooting Fire Alarm Systems

  1. Preparation
  2. Identification
  3. Investigation
  4. Repair

1. Preparation

Preparation for troubleshooting may seem minor but is crucial. Having as much information as possible beforehand can be the difference between a quick fix and a prolonged repair. Technicians should develop a habit of asking questions like:

  • Do I need specific PPE?
  • Is special access required?
  • What details has the customer provided about the trouble? (Depending on the information given, you may want to check your vehicle inventory to ensure you have spare parts specific to the site.)

Basic tools required for troubleshooting:

  • DMM (Digital Multi Meter)
  • Ladder
  • Multi-driver
  • Wire strippers
  • Combination pliers (linesman’s)
  • Various end-of-line resistors (2.2k, 3.9K, 4.7K, 20K, 47K)

Additional tools such as toners or voltage detectors can be helpful. However, for the purposes of this troubleshooting series, the tools listed above are the minimum required.

Once you arrive on site, introduce yourself to the contact person. Ask questions that may help in the investigation, such as whether any recent work was performed or if there was water infiltration in the building. Inform them that you may need access throughout the building based on your findings. If available, ask for as-built floor plans, as knowing circuit routing can save time.

Before starting, call the central monitoring station to place the system on test and notify the fire department that you’re working on the fire alarm system.

2. Identify

The next step is to identify the system trouble. The type of trouble and the level of detail available will vary depending on the fire alarm system. Older conventional systems may have only status lamps, meaning a few extra steps may be necessary to diagnose the issue. CPU-based fire alarm panels with LCD displays can provide much more detail. As technology evolves, fire alarm systems are becoming more integrated and cloud-based, allowing you to access real-time information via a smartphone or web browser.

For this troubleshooting guide series, we’ll assume we’re working on basic conventional panels with status lamps. The type of trouble will determine the investigation approach—whether it’s a panel-based issue that may require hardware replacement or a circuit integrity issue needing field wiring inspection.

3. Investigation

Once you’ve identified the specific trouble type, move to the investigation phase. Troubleshooting fire alarm systems is largely a process of elimination. Ruling out faulty Fire Alarm Control Panel (FACP) hardware is a critical first step before investigating field wiring.

Examples:

  • Checking power supplies for charging currents before replacing batteries
  • Installing end-of-line resistors on input or output circuits to rule out faulty FACP components. If the trouble clears with the appropriate resistor installed at the panel, it indicates the panel components are functional.

If the issue lies with field wiring or devices, the process of elimination continues. This series will cover troubleshooting the following common issues:

  • Power supply troubles
  • Open circuit on conventional initiating circuits
  • Open circuit on conventional indicating circuits
  • Short circuit on conventional initiating circuits
  • Short circuit on conventional indicating circuits
  • Ground faults

4. Repair

Once the investigation is complete and the trouble’s cause is identified, plan the repair. It’s essential to inform the customer of your findings before proceeding. Communication between the technician, customer, and office is crucial, as each site may have specific procedures for life safety system maintenance.

Some repairs are straightforward, such as replacing a faulty device or fixing a pinched or broken wire, and can be completed during the initial call. Others may require additional trades, such as:

  • An electrician to replace a section of wire
  • A sprinkler fitter to replace fire protection equipment
  • A plumber or roofer to fix a water leak

Whenever a fire alarm system is serviced, refer to the appropriate ULC standard to ensure the system is inspected or verified to confirm proper operation. For large or complex repairs, it’s strongly recommended to consult with your local Authority Having Jurisdiction (AHJ) to determine if a permit is required for the work performed.

In upcoming issues of The Journal, we will continue our series on troubleshooting tips and techniques, offering more in-depth coverage of specific issues you may encounter while servicing fire alarm systems.

Thomas Richards is an experienced fire alarm industry professional with 19 years of expertise in a variety of roles, from hands-on technical positions to management and education. Over the course of his career, Thomas has developed a well-rounded skill set, having worked as a Fire Alarm Draftsperson, Technician, Estimator, and Project Manager.

With an extensive background in both the technical and operational aspects of the fire alarm field, Thomas brings a comprehensive understanding of design, installation, code compliance, project management, and client relations. His diverse career gives him a unique perspective on the challenges and opportunities facing the fire alarm industry today.

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