What is NAC 2 fault?
Somewhere on the NAC2 circuit a wire is broken or a connection has come loose. The circuit is not continuous. If the voltage on NAC2 is much lower as was measured on NAC1, that means the NAC2 circuit is shorted.
What is NAC trouble in fire alarm system?
An Open NAC is a trouble on a fire alarm panel that shows that a wire in the building, somewhere along the Notification Appliance Circuit, or horn / strobe circuit, has has broken wire or it has come loose from a screw terminal or splice.
What does NAC1 mean on a fire panel?
What does NAC 1 Open mean? NAC stands for Notification Appliance Circuit and is used for the fire horns, strobes, bells, chimes, and speakers to notify occupants and the fire department of an alarm.
How do you troubleshoot a ground fault on a fire alarm system?
To find a ground fault, the first thing you should do is *remove all wires from the fire alarm control panel. If the ground trouble goes away, then you’ve ruled out the possibility that it is not an internal ground within the control panel.
What causes ground fault on fire alarm system?
Causes of Ground Faults in Fire Alarms Ground faults often occur due to a breakdown of insulation, a direct short circuit, crushed or pinched wires, or wires that become exposed to water.
What devices are on a NAC circuit?
Fire horns, bells, strobes, chimes, and speakers all have Notification Appliance Riser Circuit Wiring in common. Under normal circumstances, this circuit is in either supervision or alarm.
What is a telco line fault?
“Telco Fault” is a message that indicates that something may be wrong with the system’s telephone communication. If this message is shown, the user should find out what is causing the communication error and fix the problem. A user can also disable this error to stop it from being displayed.
How do you find a ground fault on an alarm system?
To locate a ground fault, look for continuity to ground on each circuit. This new analog ohmmeter will show infinite ohms when the conductor is not exposed to an earth ground. If the insulation is compromised and/or the copper is directly connected to ground the ohmmeter will indicate 0 ohms.
How does a NAC panel work?
The panel uses continuity to supervise the wires of the Notification Appliance Circuit. During alarm conditions, when the voltage on the Notification Appliance Circuit (NAC) is as shown, the diode conducts to allow power to light or sounder.
How many smoke detectors can you have in one loop?
The maximum number of smoke alarms that should be interconnected per NFPA 72 standards is 12. Always make sure the smoke alarms you are interconnecting are compatible. In addition to the 12 smoke alarms in the series, you can connect up to 6 compatible devices like door closers, bells, or lights.