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Can Class A wiring be used for speaker circuits? -- Our client is insisting on Class A for the speaker circuits, instead of Class B... Read More

What Does a Building Cross-Section Look Like? -- From the description of what the engineers want, a Building Cross-Section looks like a standard Fire Alarm Riser Diagram - with ... Read More

Where Can We Get Parts for our Unsupported System? -- Our fire alarm systems are no longer supported by the manufacturers, can you suggest how we can get the parts we may need in the future?... Read More

Can an SLC loop (Signaling Line Circuit), whether Class B or A, also carry the power to activate (turn on) a horn strobe? -- The Signaling Line Circuit (SLC) is meant to carry signals between addressable devices (Modules and Detectors) and the panel. In some ways, the addressable devices can be thought of as extensions of the panel itself. The SLC can be thought of... Read More

Standby Batteries - Is there a reason why I shouldn't change them myself? -- I am OK with the cost per battery but I am having a little heartburn over paying someone $115 to do a simple replacement of the batteries. UNLESS I am missing a step that I am unaware of? I believe I need to notify our alarm company that I am changing batteries and to put us in test mode. Read More

Can a Backup Generator be Used for a Fire System? -- For backup, does the signal power expander only use batteries as the power source or would a/c or a generator ever be used? Read More

Area of Refuge, what should the upkeep and temporary usage be? -- What should be maintenance aspect of Refuge area in terms of Upkeep, Temporary Usage etc.? We often get request for temporary stowing and using Refuge area for minor works including welding. Read More

Why reverse polarity for fire alarm horns? -- A fire horn is turned like a light; it turns on when power is applied and turns off when power is removed. But then again, to constantly check continuity of the wires (supervise the wires), the Fire Alarm Control Panel (FACP) always has power applied to the circuit. Read More

Can I Mix High and Low Voltage Wiring? -- Can phone lines, fire alarm cables, and 120-240 cables be put together in an outdoor back box? Read More

Can a Button be Installed to Release a Door Holder? -- The workers have to pop the door off the magnet when church starts. Some of the workers are older and have difficulty closing the door. Read More

What Causes an Open NAC? -- I am going to a job site where on the service call ticket states that a NAC is reading open circuit. What can cause an open circuit on the NAC line? Read More

Can the fire department make the owner bring the whole fire alarm system up to code? -- We failed the inspection with city due to lack of signage at pull stations in an existing apartment building. The signs are supposed to say LOCAL ALARM ONLY - IN CASE OF FIRE CALL 911 Read More

I'm Having Trouble With a Door Release -- While trying to trouble shoot why the door release for the front door is not working, one of the conductors grounded out against the fire alarm panel chases. This caused the door release to activate. Any thoughts? Read More

Are All Smoke Detectors Polarity Sensitive? -- I have a question... Is it important for smoke detectors to be polarity correct? Are all smoke detectors polarity sensitive? Read More

Can You Tell Me how the Red Box on the Wall Operates? -- I moved into a 1-bedroom apartment recently that has 3 smoke detectors (the flat, round kind mounted on the ceiling), but also mounted on one wall is a red strobe alarm... Read More

Do I Have to Go Off Line? -- Do I have to go offline to replace the batteries in the duct detector panel? Also, will I have to reset any equipment or systems? Read More

Can I Relocate a Strobe Without Reprogramming? -- Do the technicians have to reprogram the fire alarm system after relocating devices just a few inches from their original position? Read More

Can We Use Waterflow Switches for Liquid Suppression Systems? -- Can we use the Flow Switches and Pressure Switches that are used with water lines, for fire suppression system, if fire suppression system uses NOVEC 1230 liquid? Read More

How Can We Fix Intermittent Beeping Troubles? -- We have a fire alarm system installed ~ 2000, it started beeping trouble, runs through all the points as troubles, then restores to normal. Fire alarm technicians cannot figure it out. Read More

Is There Any Reference to Font Size for Labels? -- Is there any clear info on the marking as to Font size? As for is there a better description for a red marking, one that is uniform with code? Read More

How do I troubleshoot a ground fault? -- Troubleshooting a ground fault is like troubleshooting anything else. The first thing to do is stop and think. Ask yourself, what are you looking at? Read More

Douglas Krantz -- Fire Alarm Engineering Technician, Electronic Designer, Electronic Technician, Writer