We gave you a general overview of the CTU—our purpose-built monitoring hardware—and what to think about when choosing an installation location. If you missed it, you can catch up here: CTU Installation Options.

A smooth CTU installation can save you time (and a few headaches). While the process is straightforward, there are some common issues we see again and again. This week we’re sharing our top tips, the most frequent installation mistakes, and a couple of hidden features you may not know about.

Here are the 5 most common installation issues our support team encounters.

1. SGD addresses not set correctly
The CTU polls each connected SGD in sequence to check the status of the fire alarm system. It does this by sending a message from the configured port and waiting for a response from the SGD at the assigned address. If the address on a multi-droppable SGD is set incorrectly—or if it’s connected to the wrong CTU port—the two devices won’t be able to communicate.

2. Loom Installed the wrong way around
This issue is easy to run into on some panels and applies only to in-panel installations. If the loom between the CTU and the panel is connected the wrong way around, the CTU won’t be able to read the panel’s status correctly, and the panel will often flag a “Defect.” To avoid this, check the installation guide carefully, ensure the loom isn’t twisted, and confirm it’s plugged into the correct port. One of the loom wires is marked to help you align it the right way—use this as your guide.

3. SGD not enabled via panel links or programming
Some fire alarm panels require programming or a jumper to be placed in the correct position on the motherboard to enable the SGD interface. Without this, the SGD won’t be activated and won’t be able to read the panel’s status. If you notice the SGD showing a different state than the panel, this should be the first thing to check.

In addition, some CTUs require a jumper to activate the second SGD port. These jumpers are normally configured correctly before the CTU is dispatched, but if they have been removed for any reason, it can cause issues. Always refer to the installation instructions to confirm jumper placement.

In both cases, the fix is usually straightforward. If you’re unsure, our support team is happy to help you diagnose and resolve any problems.

4. Aerial Installation Issues
Two common aerial installation mistakes:

• Aerial installed horizontally - The aerial transmits in a specific pattern and must be vertical to communicate effectively with the cellular network. Laying it flat or resting it on top of the box will result in poor signal, or it may not work at all. Make sure the aerial is vertical.
• Aerial installed inside metal box - Installing the aerial inside the fire alarm panel or CTU enclosure can sometimes work with the door open, but once closed, the signal will drop dramatically—or fail completely. Always mount the aerial outside the metal enclosure for reliable communication.

5. Battery vs SuperCap confusion
The CTU is designed to use either a battery or a SuperCap as its backup power supply—but never both at the same time. The SuperCap connector has a detection pin, which the CTU uses to recognize when a SuperCap is connected. If both a battery and SuperCap are plugged in, the battery can be overcharged and potentially damaged. Our support team will usually catch this during commissioning, but the rule is simple: use either a battery or a SuperCap, never both.

Sometimes we see batteries connected to the SuperCap port, or vice versa. This won’t harm the CTU, but it will leave it without an effective backup. Always double-check which port you’re using, and avoid modifying connectors to make them fit. When in doubt, give our support team a quick call—they’ll help you get it right.

Every CTU ships with an installation guide—but we know those sometimes get left behind in the van or misplaced on-site. Don’t worry: we keep digital copies of all guides here: Installation Guides. It’s always worth having the latest version to hand before starting the install.

If you’re unsure where to start or run into something unexpected during installation, give our support team a call. They’ll be happy to help and answer your questions. A quick call upfront can often save time later during CTU commissioning.

We’ll be taking a closer look at messaging options, including:

• The different message formats and strategies we support
• How to temporarily pause messaging
• How to subscribe to all messages for a site for a set period, even if you don’t normally receive them

To maintain uninterrupted monitoring of a buildings fire alarm system even during mains power outages, our systems are equipped with backup power sources. We utilise two distinct types of backup power sources:

1. Lead acid batteries
2. Super capacitors

This post has information about both types of power source along with some things to consider when sourcing replacements.

General Information
When buying a lead-acid battery, there are several important factors to consider to ensure you choose the right battery for your needs. Lead-acid batteries are used in a variety of applications including vehicles, uninterruptible power supplies (UPS), solar energy storage systems, and more. Here are some key considerations:

• Battery Type: There are different types of lead-acid batteries, including flooded (wet cell), gel, and AGM (Absorbent Glass Mat). Each type has its own advantages and disadvantages, so choose the one that best suits your application.
• Capacity: The battery capacity is measured in ampere-hours (Ah) and indicates how much energy the battery can store. Consider your power requirements and choose a battery with sufficient capacity to meet your needs.
• Voltage: Lead-acid batteries are available in various voltages, such as 6V, 12V, and 24V. Ensure that the battery voltage matches the requirements of your equipment or system.
• Cycle Life: Cycle life refers to the number of charge-discharge cycles a battery can endure before its capacity significantly degrades. A longer cycle life indicates a more durable battery.
• Maintenance: Some lead-acid batteries require regular maintenance, such as checking water levels and adding distilled water. AGM and gel batteries are generally maintenance-free, while flooded batteries may need more attention.
• Application: Consider the intended application of the battery. Different applications may have specific requirements for factors like discharge rate, depth of discharge, and temperature tolerance.
• Size and Form Factor: Ensure that the battery physically fits in the available space in your vehicle or equipment. Consider dimensions and form factor when choosing a battery.
• Charge and Discharge Rates: Some lead-acid batteries are designed for high discharge rates, making them suitable for applications like starting vehicles, while others are better for deep cycling and continuous power supply.
• Temperature Performance: Lead-acid batteries' performance can be affected by temperature. Some batteries perform better in extreme temperatures than others. Consider the operating temperature range of the battery.
• Brand and Quality: Opt for reputable brands known for producing reliable batteries. High-quality batteries tend to have better performance and longer lifespans.
• Warranty: Check the warranty offered by the manufacturer. A longer warranty period can indicate the manufacturer's confidence in the battery's quality and performance.
• Price: While cost is a factor, prioritize quality and suitability for your application over the cheapest option. A higher upfront cost for a better battery can save you money in the long run due to longer lifespan and better performance.
• Safety: Ensure the battery meets safety standards and regulations. Lead-acid batteries can release potentially harmful gases, so proper ventilation may be necessary, especially in enclosed spaces.
• Charging System Compatibility: If you're using the battery in a vehicle, ensure that your vehicle's charging system is compatible with the type of lead-acid battery you choose.

​Selecting a replacement
When it comes time to replace a lead acid battery do think carefully when selecting a replacement. Whilst it can be tempting to opt for the cheaper option, as a general rule they won't last as long or perform as well. Purchasing a more expensive option from a reputable brand will often save time and money in the long run.

General Information
A super capacitor, also known as an ultra capacitor or electric double-layer capacitor (EDLC), is an energy storage device that stores and releases electrical energy through the electrostatic separation of positive and negative charges. Unlike traditional capacitors that use a dielectric material to store charge, super capacitors store energy in an electric double-layer formed at the interface between a high-surface-area electrode and an electrolyte.

Some of the key characteristics of super capacitors are:

• High Power Density: Super capacitors can deliver and absorb electrical energy rapidly, making them suitable for applications requiring high power bursts, such as regenerative braking in electric vehicles or smoothing out fluctuations in renewable energy systems.
• Fast Charging and Discharging: Super capacitors can charge and discharge quickly, often within seconds or milliseconds. This rapid energy exchange is advantageous for short-term energy storage and rapid energy release.
• Long Cycle Life: Super capacitors have a high cycle life compared to batteries. They can endure hundreds of thousands to millions of charge-discharge cycles without significant degradation, making them durable for frequent cycling applications.
• Low Energy Density: While super capacitors excel in power delivery and rapid cycling, they generally have lower energy storage capacity (energy density) compared to batteries. This limitation makes them suitable for applications requiring short bursts of energy but not for long-term energy storage.
• Temperature Sensitivity: Super capacitors' performance can be affected by temperature fluctuations, which may impact their capacity and power output.

We use super capacitors in our systems where either the overall power requirements are lower, or space is at a premium.

Selecting a replacement
If you believe that a super capacitor connected to one of our systems needs to be replaced, please contact us and we'll guide you through the process.