What Do I Use and Where?

So you decided to install a hard wired alarm system.  You researched what detection sensors you need, or to place them in your home.  But how will they connect back to your main security control panel?

Let’s go over key components of hard wired alarms systems to see which type of wire is best suited for each:

Intrusion Components

  • Keypad – Traditionally a keypad on the wall is the way users interact with their hard wired security system. It’s used to arm and disarm the system by entering a security passcode, and, as such, has to be very reliable under all conditions. For these devices a ready flow of power is generally delivered via 22/4 security wire connected to the main panel. Two 22 gauge wires are used for power (+12VDC and GND) and the remaining two for data communication. Many dealers daisy-chain additional keypads to the previous one eliminating the need to run another wire all the way to the control panel. However, we do not recommend this practice.  The first is the longer the run, the more the resistance and lower the voltage to the keypad.  The second is from a troubleshooting point of view.  If a problem occurs somewhere on the cable run, then multiple keypads can be impacted.  Always home-run security devices individually to your control panel.  Yes it means more cost and labor, but any troubleshooting and problem resolution is much, much easier.
  • Motion Detectors – These are “active” components requiring a steady supply of power and two wires to carry the internal relay status. Open means motion detected, closed means no motion (normally closed).  Many commercial security systems may have extra connectors for tamper protection, but this is rarely the case in home security alarm systems. A good 22 gauge security wire with 4 conductors (22/4) is generally all that is needed.
  • Door and Window Sensors – These devices are passive devices, door and window sensors don’t require a separate source of power.  A 22 gauge security wire with 2 conductors (22/2) should be used to connected them to the control panel.  Just make sure to double-check that your sensor is really passive. If it’s active, use 4 conductor wire (22/4).
  • Smoke/ Heat and Carbon Monoxide Detectors – These sensors have the same wire requirements as motion detectors (22/4), but can be daisy-chained together for more efficient wiring.  These devices are normally open (NO) so that if a fire melts the wire conductors together, this will insure a fire alarm signal.  In commercial applications 18 gauge wire is used and a red outer sheath to make sure other installers understand this is life-safety cabling.  Heat only devices are generally passive (no power required) so 22/2 wire is fine.  Again in commercial applications, 18/2 red is the norm.
  • Siren – Because sirens (and strobes) draw more power than other components of an alarm system, it’s recommended to use an 18 gauge security wire with 2 conductors. A doubled up pair of 22 gauge wire is many times used as an alternative. One note for exterior mounted siren – another pair of wires is needed for tamper protection.  This can mean 18/4 cable or 22/4 for the sounder and 22/2 for the tamper.

IP Security Cameras

For all practical purposes, your choice of network cabling will be limited to Cat5e and Cat6 cables when dealing with wired surveillance cameras. It’s possible you may have some Cat5 cable lying around your house, but it’s now considered obsolete and should be avoided. Cat5 cable is limited to 100 Mbps and 100 MHz, and you can do much better than that now.

The “e” in Cat5e stands for “enhanced”, and the cable is designed to support fast speeds of up to 1000 Mbps, while greatly reducing interference between individual wires inside the cable, something you absolutely don’t want in any alarm wire. This would be your cable of choice, if it wasn’t for the existence of Cat6 cable.

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 cross-talk reduction make this wire as future-proof as it gets. The main downside (beyond higher cost) with Cat 6 wire is that all that extra shielding adds a lot of weight and extra bulk.

Analog Security Cameras

Coax cable for traditional analog (non-digital) cameras used for surveillance come in spools and pre-cut lengths of RG59 Coax Cable, or RG6 coaxial cable if very long runs are necessary (commercial generally). Coax cable is just the video wire by itself and is good for running CCTV video signals up to 300ft max.

Siamese cable is an all-in-one security camera wire that is made up of video and power cables. The power cable is standard 18 gauge wire and the video part is RG59 coax cable. This type of camera wire is available as a spool of wire in 500ft or 1000ft lengths without any connectors, or as premade cable with bnc connector for video and 12V DC jack for power already attached to the camera cable from the factory. This siamese camera cable is the most popular since it makes security camera wiring very simple by letting you supply the camera power from inside where the DVR is located.