MSR lights not always turning on

Problem

On 22nd March 2024 a MEG Operator reported the MSR lights were failing to turn on every time. Only after waiting a few minutes did they come on again. Other MEG Operators may have come across this problem previously but not reported it, or not noted it in the Maintenance Log.
This inconsistency with the lighting had been seen before, but not for a year or so (the MSR lighting UPS battery was replaced in May 2022).
No fuse was found to be tripping, and an email was sent to VAC asking for advice.

Solution

After emailing a photo of the UPS connections, VAC noticed a wrong connection.
This probably occurred when the UPS was put back together/connections remade, after the battery replacement in 2022.
The UPS has four outlets, three are "Battery Backup" and one is "Surge Only".
In the case of a power outage, battery power is automatically provided to the Battery Backup outlets, whereas the Surge Only outlet is always "ON" (when utility power is available), and DOES NOT receive any power during a power outage.
The MSR lighting setup has two yellow power cables, one with a Black connector and one with a Grey connector. The Black connector is now known to require continuous current/power and was incorrectly attached to a Battery Backup outlet after the battery replacement.
After powering off the UPS, the Black cable connector was then correctly attached to the Surge Only outlet (VAC says it could also be attached directly to a wall socket), and the Grey cable connector was attached to one of the Battery Backup outlets. The Grey cable connector powers two emergency lights in the event of a power failure.
The UPS was powered on again and the lights were tested. All good.

• Image of the now-correct UPS power cable connections.