Cable voltage drop refers to the lower potential available at the far end of a cable run compared to the potential available at the power supply end. Voltage drop in access control systems is often ignored until it presents a problem and can be difficult to diagnose. The effect of voltage drop is most often
Security Cable Voltage Drop Part 1 – Explanation and Diagnostics Read More »
If you are finding a mag (electromagnetic) lock to be “sticky” or slow to release it is likely that it has a diode connected across the power terminals. Remove it, problem solved. This is a common mistake. The reverse biased diode is supposed to prevent a current spike (often call back EMF) caused by the
Mag Lock Slow to Release? Read More »
I have been asked how to power the locks for a fail safe/fail secure door using the PP8FR. Fail safe/secure doors use two electric locks, one to release on fire or emergency and one to stay locked to maintain access control back into the building. Often this is achieved by controlling the negative/ ground connection
Fail Safe/Secure with PP8FR Read More »
Many modern alarm and access control panels make use of PTC fuses. These are resettable fuses that over heat and trip if the current/heat gets above a set threshold. I have seen them used to protect main boards, reader power outputs and so on. PTC fuses generally take a little longer to trip than a
Fuse on PTC action Read More »
A pet bug bear of mine is seeing a consultant dictate that ALL access control doors MUST be fail safe & have a fire trip to unlock the door in the event of a fire alarm. In most cases this is incorrect and leads to a lower level of security, exposing the premises to intrusion.
Free Handle Exits & Fire Trips Read More »
Recently I have had several enquiries regarding the Building Code of Australia (BCA) in relation to fire trips. Security installers, consultants and clients often have conflicting ideas about what is required under the BCA. This leads to confusion and doubt, access to the BCA is not cheap and therefore it is often not consulted. This
Electric locks & Fire Trips Read More »