Engineering guide
Galaxy VS alarm messages explained
A Galaxy VS reports every alarm on its display with a severity colour: blue is informational, yellow is a warning and red is critical. Read the exact message in the active alarms log, note the time, check load and room conditions from the front, and call a technician for anything red, any battery warning, or any alarm that keeps coming back.
Key facts
- Severity colours: Green none, blue informational, yellow warning, red critical
- Event log depth: Latest 100 events, newest first
- Battery condition is weak: Capacity between 50% and 75%
- Battery condition is poor: Capacity below 50%; replace batteries
- System locked in bypass operation: More than 10 inverter/bypass transfers within 75 seconds
How the Galaxy VS shows an alarm
The alarm status symbol in the top right corner of the display changes colour with the worst active alarm: green means no alarm, blue an informational alarm, yellow a warning and red a critical alarm. Tapping the symbol opens the active alarms log. The Logs screen keeps the latest 100 events, newest first, which is the record a technician will ask for.
If the display itself stops working, the operation manual says the mode can still be read from the status LEDs behind the front panel. That panel is for qualified people: on a Galaxy VS with a dead screen, write down what the unit is doing (load on, load off, alarm horn) and call for service rather than opening anything.
Battery alarms: weak and poor
Battery condition is weak (warning) means the measured battery capacity is between 50% and 75%. Battery condition is poor (warning) means it is below 50%, and the manual's corrective action is that the batteries should be replaced. Neither alarm drops the load, but both mean the runtime you designed for is no longer there.
Plan the string replacement before the next outage rather than after it, and match the block type and count of the installed string; replacement battery blocks for APC and Schneider UPS strings are listed by size, and the swap itself belongs to a technician with the right PPE.
Load, input and bypass alarms
- Load on UPS is above warning level (warning): the load passed the warning level you set. The manual says to reduce load on the system.
- Overload or short circuit on UPS (warning): the load exceeds 100% of rated capacity or there is a short circuit on the output. Shed load if you can, and have the output checked if the alarm appeared with no new equipment.
- Input voltage out of tolerance (warning): the utility or generator feed is outside the UPS window. Expect battery operation until it returns.
- Bypass voltage out of tolerance (warning): the bypass source is out of tolerance, so the UPS will refuse a requested transfer to bypass.
A bypass alarm matters most before maintenance: with no healthy bypass, a transfer for service work cannot happen safely. The static bypass guide explains why.
Cooling, power module and bypass switch alarms
- Air filter technical check recommended (informational): the filters are due for a check as preventive maintenance; they may need replacing.
- Power module fan inoperable (warning): one or more fans in a power module have stopped and fan redundancy is lost.
- Static bypass switch inoperable (critical): the UPS cannot go to static bypass.
- System locked in bypass operation (critical): the system toggled between inverter and bypass more than 10 times within 75 seconds and stayed on bypass.
- Breaker MBB closed (warning): the load is on maintenance bypass, fed with unprotected power.
The fan, bypass switch and lock-in alarms are service calls. For scheduled filter, fan and capacitor work, our APC and Schneider maintenance team can fold the visit into a preventive maintenance plan.
What an operator can safely check
- Read the message, severity and time in the active alarms log, and photograph the screen.
- Look at the load percentage on the display and ask what was switched on recently.
- Check the room: temperature, blocked vents at the front, anything stacked against the cabinet.
- Note whether the unit is on battery, on bypass or on maintenance bypass.
Stop there. Breakers, power modules, battery modules and anything behind a panel are technician work. Red (critical) alarms, battery alarms and any alarm that returns after clearing need a visit; see three-phase UPS preventive maintenance for what a visit covers.
Related pages
Common questions
What does a red alarm symbol mean on a Galaxy VS?
Red means at least one critical alarm is active. Open the active alarms log to read it, note the time, and call for service.
Is Battery condition is poor urgent?
It does not drop the load, but the manual defines it as capacity below 50% and says the batteries should be replaced. Runtime during the next outage will be short.
Why will my Galaxy VS not go to bypass?
Two alarms in the manual block it: Bypass voltage out of tolerance and Static bypass switch inoperable. Both need the bypass source or the switch checked by a technician.
What does System locked in bypass operation mean?
The system switched between inverter and bypass more than 10 times within 75 seconds and stayed on bypass. Find out why before returning to normal operation.
Can I clear Galaxy VS alarms myself?
Informational reminders such as the air filter check can be handled during maintenance. Warnings and critical alarms point to a cause that should be found, not just cleared.
Sources, checked October 4, 2026:
- Schneider Electric, Galaxy VS UPS Operation, 990-5910G (5/2025), pp. 12, 48, 66, 68, 69, 71, 73, 74
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