How to Trouble-shoot AC Power Loss

[#1]

Issue

 Will an AC loss trigger the Earth Fault LED?

Solution

Yes, an AC loss will trigger the Earth Fault LED.

For more information on AC power loss, please see below.

4.1 Power Conditions

The D10024 supervises its AC power supply and standby batteries.

4.1.1 Power Failure Signal

If the 120 VAC power source is interrupted, the AC Power LED will flash, the panel buzzer will sound and the amber

System Trouble and Earth Fault LEDs will light. The alphanumeric display will no longer be illuminated and it will show an “AC Fail” message and provide information about the failure and the status of the standby batteries. If the standby batteries fail, the AC Power LED will go out.

4.1.2 Power Failure Signal Response

To silence the panel buzzer, enter Control Level 2 by pressing the [Shift] key, enable the control keys and press the

[Trouble Silence] key. The amber Trouble Silence LED will light.

When the 120 VAC power is restored, the green AC Power LED will stop flashing, but will remain lit, and the System

Trouble and Earth Fault LEDs will go out. The amber CPU Reset LED lights while the system resets itself and goes out when the reset is complete. The alphanumeric display returns to normal.

*Here is more information on earth faults:

Problem: The Fire System Annunciator is displaying earth fault to –VE on external wiring (or +VE).

Cause: An external wire is shorted to earth ground on either the negative (-VE) or positive (+VE) leg.

Solution: Take a meter set to DC voltage in order to isolate the fault with these following steps.

1. There are 5 wires that come from the power supply on the motherboard…. Blue, grey, red, black and green/yellow.
2. On a normal panel between earth ground (green/yellow) and black (DC negative) there should be about 1 VDC.
3. If the voltage is below 0.3 VDC the panel will be in –VE fault.
4. If the voltage is above 1.5 VDC the panel will be in +VE fault.
5. In order to find out what loop is faulted, remove the wires one at a time with a meter connected to the terminals in step 2.

Part numbers D10024A, D10024, D9024, D8024