Purpose of Listing Fire Alarm Components
Question: I would like to ask what is the reason or purpose of listing fire alarm systems and components. I don't need the procedure or the definition, that is spelled out in NFPA 72. But what is the reason to start with? My first assumption is that it is used because most fire alarm companies do not have the expertise or capabilities to determine if components (relays, etc.) are compatible with the control equipment and also that they meet the basic requirements spelled out in NFPA 72. Grounding and Bonding of Gas Piping in Buildings
The following is a comment from a Linked-In discussion concerning grounding and bonding of gas piping in buildings. It is a critical piece to understand when attempting to differentiate between GROUNDING and BONDING. The difficulty arises because bonding, in most cases, achieves at least some degree of grounding as well, but the intent, methods, and applicable conductors can be significantly different.  Lightning & Surge Protection 101 - Part 5
Today, wireless systems for telephone, alarms, security, and other applications are all the rage. Here is a cautionary tale.
- At one time, IBM, and later Simplex Time Recorder Company, manufactured electronic, self-correcting clock systems that employed a high power frequency generator wired in parallel across the electrical service. The last minute of every hour, the frequency generator would be turned on for a fixed period of time, and insert one of several available frequencies on the entire AC distribution system in the entire building. The secondary clocks, which plugged into any available single phase, 2-wire 120V outlet, each contained a signal amplifier which turned the frequency into a voltage that would energize a solenoid operated correction mechanism in each clock for system-wide synchronization. It was discovered that If two relatively proximate facilities running on the same utility feed just happened to be set to correct using the same frequencies, it would sometimes result in cross talk between building clock systems which might have one or both facilities with a slightly different Master Clock time setting cause an adjacent facility to also go into correction, with the usual result of each or both systems advancing, every hour.
Lightning & Surge Protection 101 - Part 4
When people ask me what I do, my usual response is, "I'm the last guy that gets called to fix something after everybody else who could possibly screw it up has been brought in and has failed to find or fix the problem, and usually, only after sins of the installer or subsequent service\installation people have been obscured or exacerbated by subsequent repair or troubleshooting attempts." Over the course of a career, a manufacturer's technical representative gets to see about every kind of "equipment failure" imaginable, and even some that aren't so imaginable. |
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LinkedIn Discussions
Site Features
Understanding Alarms
Discussion on Utilitizing VOIP as a Means of Transmitting a Fire Alarm Signal
Purpose of Listing Fire Alarm Components
Grounding and Bonding of Gas Piping in Buildings
Lightning & Surge Protection 101 - Part 5
Lightning & Surge Protection 101 - Part 4
April 2012
March 2012
January 2012
December 2011
October 2011
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