Power problems and outages pose significant risk to critical systems and equipment. Sags, spikes, surges, noise, frequency instability, harmonic distortion, and power failure can adversely affect process controls, PLCs, BAS, CPUs, computer servers, switches, and other sensitive electronic systems. Resulting data loss, equipment failure, down time, and even injuries and fatalities can be prevented with a UPS, or uninterruptible power supply, a device that provides instantaneous, temporary emergency power when interruption or failure occurs. UPS allow time for generators or other standby sources to take over when during power outages and supply clean power within a ±10% range when anomalies occur.
There are three main types of UPS. Standby is powered directly by the input power and provides basic surge protection and battery backup in smaller applications like personal computer protection. Line-interactive UPS is similar in operation to standby, but offers improved performance by better regulating voltage and filtering features. It maintains the inverter in line and redirects the battery’s DC path from charging mode to current supply when power is interrupted or lost. On-line UPS provides the highest level of protection by combining a double conversion power circuit and an inverter to provide both conditioned power and outage protection. This type is recommended for critical applications.
When selecting a UPS, criticality of the load, power requirements, battery run time, installation, cost, and maintenance needs should all be factored in. Proper preventive maintenance, essential to proper UPS function, is often overlooked, and we’ve seen even the most pricey, sophisticated UPS systems fail when needed due to lack of care. Most recently, Omni was called in to correct power-related issues that occurred when random dips and spikes sent PLCs and VFDs into fault, shutting down various systems and causing others to limp along, running only partially. Technicians traced the problem to loose connections and terminal corrosion in a central UPS that had not been regularly tested and maintained.
For expert advice and assistance on UPS options, issues, and maintenance, contact Omni at 908-523-0800 or 240-341-7915
Omni Instrumentation & Electrical Services, Inc. is a premier instrumentation and electrical contractor, providing superior total care solutions since 1986. Services include instrument installation, tubing installation, instrument calibration, control loop testing, startup and commissioning, power and lighting, process control wiring, BMS wiring, telecommunications and data wiring, fire alarm wiring, security wiring, process network wiring, and control panel fabrication. Omni Instrumentation & Electrical Services, Inc., is certified in Foundation Fieldbus, Profibus, DeviceNet and ASI-Bus installation.