Why Is My UPS System Beeping? A UPS Troubleshooting Guide for Server Room Managers

When a UPS system alarms, it is a sure sign that something needs investigating. Simply leaving an uninterruptible power supply on a flashing LED state is a sure way to leave your critical IT systems vulnerable to a power outage.

Sometimes it is all to easy to ignore a UPS alarm. What most people don’t realise is that the beeping pattern is a code, as the UPS system indicates the possible reasons for the alarm condition. Often it is an early warning fault that can be easy to fix (and cheaper) than if left longer.

First: Check the Beep Pattern, Not Just The Fact It Is Beeping

Refer to the UPS system manual. Most UPS devices use unit beep pattern to indicate a fault state. Simple, single beep every few seconds can mean something completely different to a more rapid or continuous tone.

The easiest check is against the UPS manufacturer’s manual. Often if you do not one to hand, there should be a digital version on the internet. Check the website for the UPS manufacturer (such as APC, Eaton, Legrand, Riello, Schneider or Tecnoware) or the related documents tab on the product webpage from the UPS suppler from whom you purchased the UPS device.

Typical UPS Alarm Examples

Here are some typical UPS alarm scenarios.

If the UPS has an LCD display, then there may also be a fault code. This same information may also be available through a remote monitoring cable (USB/RS-232) or if the UPS has a communications card slot, via an SNMP or MODBUS/TCP IP card. A dry contact/volt-free signal card will only signal a UPS fault condition; no code or reason for the alarm.

Typical UPS System Faults and What to Do

The following list details typical alarm scenarios and what could be the reason and fault correction. If the fault is not easily resolved (i.e. switch off some load to remove an overload), then corrective actions should be carried out by a suitably qualified UPS engineer or electrician, often available from your UPS supplier. If in any doubt call your UPS supplier’s technical support team. Their details are normally published on their website.

1. On Battery Power (Mains Power Supply Failure): When there is a mains power supply outage or the voltage or frequency varies wildly, the UPS will use its battery power to protect the connected load(s). This is normal operation for the UPS, whether it is a standby, line interactive or online UPS. What you can do is check whether the power supply interruption to the input of the uninterruptible system is just to the UPS itself or wider, affecting the room where the UPS is installed or the actual building. It is important to note that when running on battery power, the battery runtime is limited, so start to shutdown your IT systems and connected loads if you think the power outage could last for some time, i.e. before your battery is exhausted. Your UPS will move to a second-stage low battery warning when the battery nears exhaustion. Should mains power be restored or local generator startup, then the UPS will revert to charging its battery and the load can continue to run.
2. Low Battery Warning: During normal operation, when the mains power supply is available and stable, your UPS system will recharge its battery to 100% in anticipation of the next power outage. When the battery is nearing exhaustion, typically at 20% load (though this is settable for some uninterruptible power supplies) or between 2-3 minutes of remaining battery power, the audible alarm will become more rapid. It is very important to prepare for a complete UPS power down now. If you have installed UPS monitoring software, this is the state at which any automatic server or computer shutdowns should be automatically initiated. Should mains power be restored, then the UPS will revert to charging its battery and the load can continue to run.
3. UPS Overloads: when the connected load is greater than 100% of the UPS systems’ capacity, the overload alarm will sound. The overload can be intermittent, such as the start-up of an IT server. In an online UPS, the overload is handled as the online system uses it’s inbuilt automatic bypass to handle the short-term (milliseconds) overload condition before restoring output to the UPS inverter. In standby and line interactive UPS, a large overload can cause the UPS to shutdown to protect itself. No UPS system should be run in overload in the long term and generally for online system, the specification is quoted in seconds and with derating, in minutes. The ideal loading of a UPS is within the 80% mark. This leaves 20% for overload conditions. Anything greater should be investigated and either load removed and move to another UPS systems protection or the total load reduced. Look at what doesn’t need critical power and could be load-shed in the event of a power outage.
4. Replace Battery When carrying out UPS surveys, this is probably the most common fault we find. Most UPS up to 3kVA have valve regulated lead acid batteries with a 5-year design life. This means that they will need replacing during years 3-4, if operated within a 20-25degC or less environment. Heat kills VRLA batteries and so a higher ambient will more rapidly deteriorate the battery pack. Either replace the battery or the UPS itself. Most UPS suppliers offer battery replacement kits, and some UPS have user-replaceable batteries. Or you can your UPS supplier for an onsite UPS battery replacement service. The benefit of replacing the UPS system is not only a new battery set but also a new UPS warranty which can be 2-6 years. Remember though that the standard battery warranty is only 12months and it’s the UPS electronics that have the longer warranty.
5. UPS Fault Condition Most UPS have 24hour self-test routines and this can pick up faults. There is also regular monitoring of aspects such as internal temperatures, AC and DC voltages and frequencies, and even cooling fans. If there is an internal fault, this indicates a serious, detrimental degradation in UPS performance. Put simply, your UPS may be in ‘limp mode’ and unable to provide backup power in an emergency. Check the fault code (if provided) to the manual, and/or call the UPS supplier’s technical support line. In most cases the fault requires intervention from a suitably qualified engineer.
6. Site Wiring Fault The electrical supply to your UPS system can itself develop a fault. The input supply to your UPS system is supplied via the building’s electrical wiring and the fault could be an earth-fault, loss of neutral or another type of electrical wiring fault. Call for qualified electrician to investigate.

Any UPS fault condition should be immediately investigated but by a suitably qualified UPS engineer, electrical engineer or electrician. Never attempt to solve the fault if it requires work internal to the UPS system or local wiring.

UPS Remote Monitoring

Most UPS systems offer some form of remote communications. Using some form of remote monitoring is important as it will be 24/7 with escalated alarm lists which will send alarm messages to key individuals, either via email or SMS text messages. Where the UPS does not offer a communications card slot (SNMP, MODBUS or signal contact) then a separate environmental monitoring unit can be used to monitor information from the UPS, its electrical suppliers (AC and DC) and ambient environment to provide this function.

An example being the AKCP sensorProbe SP2+ with four sensor parts and internal modem. This device can monitor AC power supply presence, temperature and humidity, signal contacts, and using virtual sensors SNMP and MODBUS information, via dashboard and sending email and SMS text alerts to alarm conditions.

Summary

UPS manufacturers provide audible alarms and LCD error codes to help you quickly identify a UPS alarm condition. It is often easier and potentially cheaper to deal with a fault condition earlier, rather than later, and also can provide greater assurance that your system is uninterruptible in the case of a power outage.

The Technical Support team at Server Room Environments is always available to help diagnose and solve UPS alarm conditions. Simply contact the team either via phone or email or raise a support ticket. We also offer an emergency response service and maintenance contracts to ensure UPS system alarms can be quickly resolved and UPS systems returned to their normal operational state.