In offices, server rooms, or homes, UPS power supplies act like “power bodyguards,” silently protecting critical equipment such as computers and servers, preventing data loss or equipment damage caused by sudden power outages. However, this “bodyguard” can occasionally “act up” and experience various malfunctions.
Many people’s first reaction to this problem is to call a repairman, which is not only expensive but also time-consuming. Actually, most common UPS faults have a set troubleshooting process, and you can solve them yourself!
1. The mains power is on, but the UPS is calling “power outage”? This troubleshooting method is sure to be correct.
Have you ever encountered this situation: even though there’s no power outage, the UPS keeps issuing mains power failure alarms? Don’t panic, this is probably not a major problem, and it’s likely caused by one of the following reasons:
One possibility is that the mains input circuit breaker tripped, which could be caused by line overload or poor contact.
Second, the input AC cable may not be properly connected, such as a loose plug or an aged or damaged cable.
Third, the mains voltage is abnormal, either too high, too low, or the frequency is incorrect, exceeding the UPS’s range of operation.
Fourth, the UPS’s built-in input circuit breaker or switch may be damaged, or the internal fuse may have blown.the mains power detection circuit inside the UPS is faulty, resulting in a false alarm.
The troubleshooting is quite simple; just follow these steps: First, check if the input circuit breaker has tripped. Then, check if the input lines are securely plugged in and undamaged. If the mains voltage is abnormal, you can leave it alone if it doesn’t affect the equipment’s operation. If it has a significant impact, start the generator to supply power. If you find that the circuit breaker, switch, or fuse is damaged, replace the corresponding component directly. Finally, check the UPS’s mains detection circuit to eliminate any internal faults.
2. When the mains power is cut off, the load also drops? The problem is usually with the battery or the inverter.
This is one of the most troublesome faults: when the mains power is normal, the UPS output works fine, but once the mains power is cut off, the loads such as computers and servers will lose power directly, and it cannot play the role of backup power supply at all.
In such cases, the core issues are mostly related to the battery or inverter. Specific reasons include: prolonged low AC mains voltage leading to battery undervoltage; a damaged UPS charger preventing battery charging; aging or damage to the battery due to prolonged use; excessive load exceeding the UPS’s capacity, causing the UPS to bypass output; incorrect load connection, not connected to the UPS output; for long-duration models, improper battery connection or disconnection; additionally, an inverter not starting (panel control switch not on) or a damaged inverter can also cause the load to rely on AC mains bypass power, resulting in shutdown when AC mains power is interrupted.
The solutions are as follows: First, fully charge the battery when the mains power is normal. If the mains power is consistently low, add a voltage regulator to the UPS input or start a generator to charge the battery. Check if the charger is working properly; replace any old or damaged batteries. Reduce the number of loads to prevent overloading, and ensure that the loads are correctly connected to the UPS output. For models with long delays, check the battery connections to ensure they are connected correctly and securely. If the inverter is not starting, simply turn on the control switch on the panel. If the inverter is damaged, it needs to be repaired or replaced.