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How to Replace a Power Supply in a Visonic Alarm Control Panel

Occasionally, the internal Power Supply Unit (PSU) on Visonic wireless control panels may fail.  The failure is usually indicated by the message ‘AC FAIL’ on the control panel display and/or ‘CPU BATT LOW’.  Both of these point to the probable failure of the PSU.

Before confirming that the PSU has failed, check that the mains supply to the panel is present and also that the back-up battery is in good condition.  The back-up battery in the control panel is a rechargeable unit and should remain serviceable for around 5 years. You can also ask a qualified electrician to check the output from the PSU. 

replacing a visonic power supply.jpg

Visonic install only 2 types of power supply in their range of PowerMax and PowerMaster control panels. Although at first glance they may look similar, they are not the same and you must ensure that the correct one is fitted. The 2 power supplies used are as follows.

Part No: 260-301720
Dimensions: Length: 83mm x Width: 46mm​​​​​​​x Depth: 22mm

Compatible with:

  • Visonic Powermax Pro

  • Visonic Powermax Complete

  • Visonic Powermaster-30 PG2

  • Visonic Powermaster-33 PG2

  • Visonic Powermaster GT64 PG2


Visonic Replacement Power Supply PSU.png

Part No: 260-302379
Dimensions: Length: 68mm x Width: 28mm​​​​​​​x Depth: 22mm

Compatible with:

  • Visonic Powermax Express

  • Visonic Powermaster-10 PG2


PowerMax Express - PowerMaster 10

Tools Required

  • Small electrical screwdriver

  • Small cross-point screwdriver

Removing the Failed PSU

WARNING:  Remove all mains power to the control panel BEFORE opening the Control Panel.

  1. Open the control panel by loosening the two screws at the bottom of the control panel and removing the cover.

  2. Disconnect the back-up battery.

  3. Locate the PSU and remove the cover from the mains terminals.

  4. Disconnect the mains supply from the terminals.

  5. Disconnect the PSU output at the panel PCB.

  6. Remove the two screws securing the PSU cover.

  7. Remove the faulty PSU.

Fitting the new PSU

  1. Locate the new PSU in the correct position.

  2. Arrange the output cable such that it exits from the side – in line with the cut-out in the cover and such that the little black connector will be under the cover when fitted.

  3. Fit the cover over the PSU – ensuring that it is positioned correctly.

  4. Secure the cover in position with the two screws – take care not to cross-thread the screws.

  5. Channel the output cable alongside the PSU cover , under the guides and plug it into the PCB.

  6. Re-connect the mains cable to the PSU input terminals – VERY IMPORTANT - observe the Live and Neutral markings.

  7. Reconnect the back-up battery.

  8. Re-fit the control panel cover.

  9. Re-connect the mains supply.

If the control panel goes into alarm, enter the user code to silence it.

The control panel should show several troubles which may be live or in memory.  Troubles in memory are likely to be ‘CPU TAMPER’, ‘AC FAILURE’.  These troubles will clear once the system has been armed.

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