DSC Panel AC Power Failure — How to Fix

What Does This Error Mean?

DSC AC Power Failure (displayed as 'AC POWER FAILURE' on LCD keypads, or Trouble Zone 2 light) means the panel's 16.5VAC transformer has lost its mains supply. The panel switches automatically to the backup battery and continues to protect your premises normally. Restore AC by checking the transformer outlet and the breaker feeding the alarm circuit.

Affected Models

DSC PC1616
DSC PC1832
DSC PC1864
DSC PowerSeries Neo HS2016
DSC PowerSeries Neo HS2032

Common Causes

The breaker feeding the transformer's wall outlet has tripped
The transformer's plug has been accidentally unplugged from the outlet
A power outage has cut mains electricity to the property
The transformer itself has failed and is no longer producing output voltage

How to Fix It

Check whether there is a general power outage at the property

If other appliances in the same area have also lost power, the outage is from the utility and not a panel-specific fault. The DSC panel will run normally on battery backup. Wait for utility power to be restored — the trouble will clear automatically.
Locate the transformer and verify it is plugged in

The DSC transformer is a small plug-in box connected to a standard 120V outlet, usually near the alarm panel enclosure or in a utility area. Confirm it is firmly plugged in and the outlet is live (test with a lamp or phone charger).
Check the breaker feeding the transformer's outlet

Find the breaker panel and look for any tripped breakers (middle position). Reset the breaker feeding the outlet where the transformer is plugged in. If it immediately trips again, there may be a wiring fault on that circuit.
Measure transformer output voltage

With a multimeter set to AC voltage, measure across the two terminals on the transformer's secondary output wires (the wires going into the panel's AC terminals). Output should be approximately 16.5VAC. Zero voltage with a live input means the transformer has failed and needs replacement.
Clear the trouble and confirm the keypad returns to normal

Once AC is restored, press the * key on the keypad, then enter your access code to acknowledge and clear the trouble. The AC Power Failure indicator should go off. If the trouble returns within minutes, the transformer or wiring needs further investigation.

Frequently Asked Questions

How long will my DSC panel run on battery backup during an AC failure?

A standard DSC 12V 7Ah backup battery provides approximately 4–12 hours of standby depending on connected devices and how often the siren activates. The panel will continuously monitor and detect intrusions during this time. Replace the battery every 3–5 years to maintain this backup capacity.

Will my monitoring centre be alerted to the AC Power Failure trouble?

Yes — if your DSC panel is connected to a monitoring centre, the AC failure trouble is typically reported after a delay (usually 30–60 minutes, to avoid false reports during brief outages). Your monitoring company may contact you. Confirm with your alarm company what their reporting threshold is for AC troubles.