what kind of wire should i use for an alarm system

What Kind Of Wire Should I Use For An Alarm System?

When it comes to wire, the higher the number, the smaller the wire conductor. The recommended gauge wire for alarm components is solid or stranded 22 AWG, two-conductor wire (black and red) or 22 AWG, four-conductor wire ( black, red, green and yellow or white). 

Solid copper wire does not bend as easily as stranded wire but eliminates the chance of a loose strand of wire causing a short. 22/4 wire can still be used on devices that require only two wires.

While some alarm devices require only a 2-conductor wire, others require 4.

Non-powered devices such as doors, and windows, require only two wires. The AC transformer for the system also requires two wires, as do bells and strobes. Some sirens can use 3 (red, black and yellow) but typically also use only 2.

Powered devices such as keypads, motion detectors, glass break sensors, hardwire zone expanders, wireless receivers, and relay modules require a four-conductor wire, 2 for power, and 2 for data, or the zone wiring. Running a phone line for line seizure also requires four wires.

Always refer to the device installation manual for complete instructions. 22/4 wire can be used on devices that require only two wires, using only two of the conductors.

22 gauge wire should not be used for smoke detectors or AC power to the control panel. Smoke detectors and AC transformer wires should be 18 AWG or more extensive. 

Always review the manual for smoke detectors and the local fire codes when installing smoke detectors.

Whenever possible, every door or window contact should be wired as an individual zone. Doors tend to get much heavier use than windows which causes wear and tear on the connection and can lead to false alarm issues. 

These issues are much easier to troubleshoot when windows and doors are wired separately from each other. 

Using a sharpie, each wire should be marked and labelled at the control panel box as it is connected to avoid confusion down the road.

Components Of Wired Alarm System

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Let’s go over the main components of wired alarms system to see which type of wire is best suited for each:


Typically, a keypad is generally the only way users interact with their wired alarm system. It’s used to arm and disarm the system by entering a security password and, as such, has to be reliable under all circumstances. A steady flow of power is best delivered via a 22/4 security wire connected to the main panel. Two wires are used for control and the remaining two for data connection. Additional keypads can be connected to the previous one, thus eliminating the need to run another wire to the panel.

Main Control Panel 

It is the brain of any security system. Not only does it register and analyse input from all other components of the system, but it also facilitates communication with your telephone distribution panel and connection to smart home automation systems or computers. A Cat5e or Cat6 cable is used to satisfy the need for versatility and guarantee that the system will be future-proof and ready for expansion.

Motion Detectors

Are active components that require a steady supply of power and two wires to carry the data signal. Some more complex systems may have extra connectors for tamper protection, but this is only rarely the case in home security systems. A good 22 AWG security wire with four conductors will be everything you need.

Smoke And Carbon Monoxide Detectors

These sensors have the exact wire requirements as motion detectors but can be daisy-chained together for more efficient wiring.

Door And Window Sensors

As passive devices, door and window sensors don’t require a separate source of power. A 22 AWG security wire with two conductors should be used to connect them to the main panel. Just make sure to double-check that your sensor is passive. If it’s active, use four-conductor wires.


Since sirens draw more current than other components of home security systems, it’s recommended to use an 18 AWG security wire with two conductors. Doubled up pair of 22 AWG wire could serve as an alternative, but there’s no reason to cut corners when you can do it correctly with an appropriate wire.

Why Not Use Cat 5/6 Cable For Everything?

Given how widespread computers and sophisticated home-networking solutions have become, it’s no wonder that many people are considering using Cat 5e or Cat 6 cable for all their home security needs. This approach is, indeed, possible, but it’s essential to be aware of all downsides that come with it.

Cat 5 and 6 cable has more wire strands than what all security components (except for the main control panel) require. This increases the cost and makes the installation look very messy. Future repairs and upgrades will take much longer, not to mention that the individual wires are often thinner than your typical 22 AWG security wire, which means higher resistance.

We strongly recommend you install appropriate security wire for each component of your home security system and use Cat5e or Cat6 cables only where they are needed.

Cat 5e Versus Cat 6

For all practical purposes, your choice will be limited to Cat 5e and Cat 6 cables. Yes, there’s a good chance that there’s still some Cat5 cable lying around your house, but it’s now considered to be obsolete and should be avoided. The Cat 5 is limited to 100 Mbps and 100 MHz, and we can do much better than that. So, wipe that tear and let’s take a look at something better.

The “e” in Cat5e stands for “enhanced”, and the cable can support fast speeds of up to 1000 Mbps while significantly reducing interference between individual wires inside the line – something you don’t want in any alarm wire. This would be your cable of choice if it weren’t for the existence of cat six cables.

Cat6 makes the already great Cat5e cable even better. It can handle 10-Gigabit speeds, up to 250 MHz, and its internal wire separator and individual wire shielding for crosstalk reduction make this wire as future-proof as it gets. No, it won’t change your hovercraft, but it will support all your security and networking needs for many years to come. The only problem with Cat 6 wire is that extra shielding adds a lot of weight and excess bulk.

Wireless, Sure, But Wireless Networks Are Not As Reliable.

While a wireless system is convenient and relaxed, the stability of such a network will depend upon the wireless signal coming from the router. Unless you have an excellent network with a very solid (probably expensive) camera to go with it, you could be at the mercy of dropped signals in the wee hours of the night when you hear breaking glass or rattling around and want to take a look at what is going on outside your home. Let’s say that all inexpensive IP cameras out there have not necessarily become ready for prime time.

Wired security systems have been on the market for a long time and have a proven track record of reliability. The technology has been improved to perfection by many individual manufacturers from all over the world, and it’s now more available and cost-effective than ever before.

That being said, wireless systems have not been slacking behind. They are so available and advanced that many people consider them as a worthy alternative to old-fashioned wired systems. What these customers don’t realise is that wireless systems are hardly worry-free and usually not even completely wireless since many of them require an additional source of power.

Wired alarm systems don’t necessitate regular battery changes. Yet, they are just as resistant to power outages as wireless systems, thanks to the ability to install backup batteries for all active components.

And if the burden of maintenance isn’t enough to convince you, consider how much more expensive wireless systems are. You can install a complete wired security system for the cost of a few minor wireless sensors.

The only real benefit is how portable wireless systems are. If you are renting and planning on moving out soon, a solid wireless system might be a good solution for the time being.

Alarm System Wiring For The Main Panel

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Hardwired home security systems need some basic alarm system wiring for main panel operation. This allows charging the backup battery, arming and disarming the system, sounding alarm conditions, and communicating with a central station. Wiring a home alarm system is easiest to do while the house is being built, but it can also be done in an existing home.

To function, the main alarm panel needs wiring for:

  • Power
  • Telephone
  • Keypads
  • Sirens
  • Auxiliary devices
  • Ground (optional)


Whether you’re planning a DIY home security system or using an alarm company, begin by choosing a location for the main panel. Good choices are in a master bedroom closet, laundry room, or another out-of-the-way place.

Power Wiring

A home alarm system is powered by a low-voltage transformer, which charges a 12-volt backup battery. The battery can usually run the system for a few hours in case of an electrical outage. Alarm system wiring from the transformer location to the main panel should be 4-conductor firewire, 22-gauge minimum.

Run the wire to an unswitched electrical outlet as close to the panel as possible. If the distance is over 50 feet or so, use 18-gauge wire if you can. Some boards are sensitive to tiny voltage drops over long power runs and give a low battery indication even under normal conditions.

Telephone Wiring

It’s always a good idea to run telephone wiring for the security panel, even if you don’t plan on using home alarm system monitoring right away. Providing a telephone connection is considered a standard part of professional security prewire, and you never know when you may decide to use it.

Run a phone wire from the main panel to the telephone service entry point. This is usually located outside the house, near the main electrical breaker panel.

Alarm System Keypad Wiring

Keypads are used to arm and disarm the security system and to view zone and system status. The system also uses them to sound alarmed and trouble tones.

As part of any basic prewire, run 4-conductor alarm system wiring to each of these locations:

  • Front door
  • Garage interior door
  • Master bedroom

Coil up two or three feet of wire at each location, just above the light switch. At the garage interior door, loop the wire above the light switches both inside the house and in the garage itself. These locations are often back-to-back anyway, in which case a single coil of wiring is okay. This allows the option of installing a keypad at either site or both.

Depending on the layout of your home, you may want to run additional 4-conductor alarm system wiring to any location that might need a keypad. Maybe you have a side entrance to the house or a floor plan with a second master bedroom option. Other places that might need a keypad for convenience include a detached garage, guesthouse, or workshop.

Sirens And Sounders

Sirens are your best method to alert a would-be thief that he has been noticed. A blaring piece alert or another loud audible sounder will drive most intruders from your home, meaning you won’t have to run into them accidentally.

Interior sirens are very effective and can also double your fire alarm sounder if you include smoke detectors with your security system.

Exterior sirens are not as frequently used anymore, though it’s an excellent idea to prewire one just in case. Outdoor sirens only help if someone is nearby during a break-in, and even then, most people ignore alarm sirens.

Your money is much better spent on adding a smoke detector, a different keypad or motion detector, or any other upgrade you may have been “on the fence” about buying.

Wiring for inside sirens should be 2-conductor firewire. Exterior sounders should be wired with 4-conductor firewire. This allows two conductors to power the siren and two more for a tamper switch.

Wiring For Auxiliary Devices

Modern security panels can do much more than sound a siren and send alarm signals. Most alarm panels offer auxiliary output relays and triggers that can be programmed for various responses. These outputs allow a board to control lights, door strikes, appliances, and almost anything else that can be operated by a switch. These devices can be activated in response to an alarm or other condition that the panel detects or on a timed schedule for repetitive events.

Alarm system wiring for auxiliary devices will depend on the specific lighting system, instrument, or function you want to perform. Your alarm company can advise you on what options are available, along with any additional wiring that may be needed.

Ground Connection

Ground wiring for an alarm system makes the lightning protection built into the panel more effective. The ground must be a good one, though, or it can cause more harm than good. Most alarm system panels will have a clearly labelled “ground” terminal to connect the ground wire.

Use heavy-gauge copper wire for ground connections, 12-gauge or more extensive. Attach the wire to a copper cold water pipe or grounding rod using a correctly sized grounding clamp.

Newer homes may be built with only a short copper water line entering the house; the rest of the water line is plastic and useless for grounding purposes.

The bottom line: If you have access to a good ground, use it. Otherwise, don’t worry about it. These days, the cost of a good grounding rod would likely be more than the price of the alarm equipment!

Different Types Of Fire Alarm Cables

Fire alarm systems are essential for any business, school, facility, home and much more. They protect us when alerts arise and deliver notification of potential threats and harm. In previous blogs, we have discussed how fire detection systems work and the differences between conventional vs. addressable fire alarm systems.

Power Limited Fire Alarm Cables.

FPL, a power-limited fire alarm riser cable, is usually the least expensive because it is the most basic type of fire alarm cable and is also recognised by the NEC (National Electric Code). FPLR cables are suitable for a vertical run through a shaft or from floor to floor within a building. 

FPLR Shielded is a power-limited fire alarm shielded cable, has the same components as the standard FPLR but includes an aluminium polyester foil shield and drain wire to protect against outside interference.

FPLP, which is a power limited plenum cable and they are recognised by the NEC for use in air ducts and plenum spaces and any other space that is used for the flow of environmental air. These cables tend to be a little bit more expensive due to the additional engineering and protection they offer. All FPLP cables are listed as having adequate fire-resistant and low-smoke-producing characteristics as well. 

FPLP Shielded cables are power limited plenum fire alarm cables with an aluminium polyester foil shield and drain wire to block an additional interference within a cable. 

Non-power Limited Fire Alarm Cables

NPLF or non-power limited fire alarm cables are recognised by the NEC and are suitable for all general fire alarm cable uses. They cannot, however, be used in riser, ducts or plenum spaces that are used for environmental airflow unless they are correctly installed within a conduit.

NPLFP are non-power limited fire alarm cables recognised by the NEC, but these cables are suitable for installation in ducts, plenums and other spaces where environmental air flows. 

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