UPS

Q: I have a situation where our UPS servicing data center rack systems are failing repetitively after replacements.

We know our mains transformer is undersized in terms of load capacity and under voltages are measured going to the input of the UPS that is providing back up power to data center in a rack mount. However these voltages measured were 110VAC and still within operating range. In another facility with the same rack systems, colleagues are saying they're seeing "brown out ...

Most UPS's are sized for the client load requirements. However in cases of smaller UPS systems won't comply with electrical regulations!
Why?
Let's consider a client needs a 30kW supply, to 2 100amp distribution boards. One 20 meters from the UPS and one 80 meters away. Each DB has some 32amp circuits up to 20m long. The distribution circuit is protected by 63amp BS60947 devices and the final circuits are 32amp BS60898. Specifically for a UPS system, what is going to define your UPS ...

UPS modules are no different to other high impedance sources such as generators, they need special consideration that some or most professional design software don't do accurately. If you're an electrical engineer you should have the ability to make suitable decisions based on experience, qualifications and information.

Do your homework, double check any digital calculations and don't expect a lot of help from manufacturers. I have tried and they don't want to assist or can't. The ...

Motor duty UPS is capable of delivering the high starting current demand of the induction motor. Bypass power supply is synchronized with the UPS output (via static bypass switch) to provide the additional current during motor starting. In most of the cases, motor is started only when the main supply is available. This helps in optimizing the UPS rating. Battery backup is used to keep the motor running in the event of power failure until the alternate power supply comes online. Hence in my op ...

An isolation transformer is a transformer used to transfer electrical power from a source of alternating current (AC) power to some equipment or device while isolating the powered device from the power source, usually for safety reasons.

What this means in reality is that a normal application for an isolation transformer is to either keep the load from generating harmful harmonics back onto the distribution bus ...

Most of the static duel conversion UPS systems operate the same. Rectifier produces a regulated output subject to its designed limits, and input source. But its output is subject to the requirements of its loading, which is the inverter and batteries. Typically the rectifier is rated at 125% of the system load. Designed to provide 100% load and 25% recharge for the batteries. Enabling battery recharge around 10 minutes for every 1 minute of discharge.

The inverters are designed to ...

To cater the single phase loads from the 3-Phase inverters, all inverter designers will use the system neutral which is used for the load distribution as well will be used as reference in order to develop the sinusoidal output phase waveform. So, every manufacturer uses different techniques depending upon the technology. But, whatever may be the technology the manufacturer uses, he has to take the neutral (which is the return path for the single pha ...

Many people think that UPS is a magic box that solves all the electrical problems. UPS systems have capacities varying from few hundreds of VAs to massive kVAs. The only thing that is worth noting in a UPS system is that, it can be viewed as a source as well as a load. Depending upon the configuration, the grounding needs to be planned. If the UPS system is transformer based, and operating only in inverter mode (Frequency converter mode), then it is called as separately derived source and out ...