Page 8 - Security Today, January/February 2020

Powering Access Control New standard allows manufacturers to design products with bigger features
BTy Ronnie Pennington
he new IEEE802.3bt PoE standard, also often re- ferred to as PPoE or 4-Pair PoE, is a game-chang- ing solution for powering 12VDC and 24VDC access control and related devices. IEEE802.3bt introduces two new types of PoE; one provid-
ing up to 55W and the other up to 75W. Unlike Hi-PoE (60W), IEEE802.3bt uses all four pairs of wire in a structured cable to evenly distribute power. This new standard allows manufacturers of powered devices to design new products with bigger features, faster motors and more capabilities.
To date, there are few products on the market that have al- ready adopted the 802.3bt standard. Aside from PoE lighting, there are some infrared illuminators that adhere to 4PPoE, but now that this standard has been ratified, manufacturers are look- ing to take advantage of this standard for new products.
There are several sources for PoE injectors that supply 802.3bt up to Type 4. For example, Altronix NetWay Midspans are avail- able in single or multi-port options with larger wattage power supplies to cut down on the number of injectors for larger proj- ects. And just recently, Altronix introduced switches offering 4PPoE outputs. This is a good indicator that we will see a lot more devices demanding more power.
When we think of power supplies, they normally have a high voltage input such as 115VAC that is converted into 24VAC or 12/24VDC. There are other power supplies that accept a 24VAC input and convert to 12VDC or lower. For example, when a sim- ple burglar alarm panel requires 16.5VAC input, the panel con-
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JANUARY/FEBRUARY 2020 | SECURITY TODAY
verts this to 12VDC. This 12VDC will also power the keypad and charge a battery for backup. Though the video surveillance world is going mostly IP and using PoE for power, HD analog cameras for the most part still require 12VDC.
A big application using power supplies hardwired with high voltage is for the deployment of electrified locks. These power supplies generally take 115VAC power input and reduce this to a 12VDC or 24VDC output. That single output is then connected to a distribution board where the electrified magnetic locks or strikes are connected. Most jurisdictions require that this power input be hardwired with a dedicated circuit. Due to the high volt- age, a certified electrician must wire this type of installation.
While some security integrators do have certified electricians on staff, the use of high voltage still adds to the cost of any instal- lation. In large cities like Chicago, Boston, or New York, electri- cians have offices in the same building as the access control sys- tem. This limits contracting your own electrician to do the work. The installation also requires dedicated conduit runs as well as expensive large gauge copper and a dedicated circuit breaker. The new 802.3bt 4PPoE standard helps curtail this costly practice.
4PPoE delivers up to 75W of total power. Using new solu- tions like Tango PoE driven power supplies from Altronix, we can harness the IEEE 802.3bt standard. Tango solutions allows for a PoE input of 15.4W, 30W, or the new 4PPoE 100W and converts it to a useable 75W of available power. With 75W available, the flexibility to power an entire access control system is a reality.
Here is the breakdown using Mercury boards, one of the most
LOW VOLTAGE
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