Power: The Unregulated Utility

Utility power in a pharmaceutical environment is unregulated by the FDA. Pharmaceutical/biotechnology companies are dependent on the quality of the power provided by the local utility. There are many issues regarding unconditioned power provided by a utility versus conditioned power provided by an uninterruptible power system (UPS). The increasing complexity of computers, computer systems, microprocessor-controlled processes, and the interaction of IT systems and computerised process systems has created a power requirement structure for pharmaceutical/biotechnology processing that is unparalleled. The power provided by the utilities can vary greatly in voltage, frequency and electrical noise. This paper will delineate the most common problems with utility power, how to rectify and minimise the exposure to power inconsistencies, and protect and maintain mission-critical processes and environments. Power has never been regulated in the pharmaceutical industry as it is not considered an active ingredient nor component in pharmaceutical processing or manufacturing. However, all pharmaceutical and biotechnology facilities use power. Power is supplied by the utility. In cases of a power outage, power is generated on-site by using auxiliary generator systems or supplied by emergency batteries. The lag time between the loss of power and the supply from the generator or batteries is usually 10-30 seconds. This is a short duration in physical time but could be catastrophic in process loss. Utility power voltages and supply can deviate from -7.5% to +7.5% from an absolute voltage value by law. Thus, a 208-phase voltage can range from 192-223 volts, as supplied by the power utility. This wide deviation from 208 volts is only one possible problem. Power surges, sags, electrical noise, harmonics, load, and other interferences can damage sensitive electrical components and accessories. Microprocessor-based devices in the pharmaceutical process, including controllers, programmable logic controllers (PLCs), PC controllers and servers, are susceptible to power interruptions and fluctuations. This can result in violation of process parameters, loss of real-time data, loss of process control, loss of archiving data, loss of batch, loss of revenue, etc.

Power problems Power failure, by definition, is a total loss of utility power. Utility power losses are caused by numerous events including lightning strikes, downed power lines, transformer malfunctions, over-demands on the grid, accidents, weather anomalies and natural disasters. In most systems, some or all of the following situations may occur: file corruption; hardware damage; data loss; data corruption; firmware damage or loss; or malfunction of the computer. Power Sag: Power sag is a short-term, low voltage supply, from the utility. The duration of a power sag can be extremely short or may last for a few seconds. A power sag can be triggered by various load and utility switching mechanisms. When a large load is started, the grid will yield to the load while stressing the existing supply and load on the grid. Utility equipment failure, utility switching, lightning, large load start-up, and demand that is greater than the power service can handle can all be contributing factors to power sags. Power sags can cause crashes to equipment and hardware damage. Typically, the hardware damage may entail memory loss, data errors, flickering lights, equipment shut-off or malfunction with automatic shut-off. Power Surge: This is the opposite of a power sag. In this case, the short-term high voltage can be 110% above the nominal supply voltage. Power surges can be caused by lightning strikes sending line voltages above 6,000 volts. Power surges, also known as 'power spikes', invariably result in both data loss and hardware damage. The resulting damage could entail problems similar to power sag. Undervoltage: Undervoltage, also known as 'brownout', is a condition that may be intentionally induced by the utility. The definition of undervoltage is when line voltage is reduced for an extended period of time, from a few minutes to as long as a few days. The utility may enact a brownout during peak demand periods to conserve power. Supply due to heavy loads exceeding the capacity can necessitate an under voltage condition. The effect of the brownout can predicate premature hardware failure, data loss and corruption. Overvoltage: Overvoltage is the opposite state from undervoltage or increased voltage for a duration of time. Overvoltage is a fairly infrequent occurrence but occurs in instances of rapid reduction in power loads, shut-off of heavy equipment, or by utility switching. Overvoltage can incur extensive hardware damage including burned-out circuit boards, component stress or loss, memory loss, data loss and data errors. Electrical line noise: Electrical line noise is a high frequency waveform caused by radio frequency interference (RFI) or electromagnetic interference (EMI). These common interferences in a power supply can be generated by local or remote influences. Equipment such as transmitters, welding devices, SCR driven printers, lightning, and electrical equipment can generate RFI and EMI conditions. Varying degrees of damage can occur from simple keyboard lock-ups to program failures, data crashes and data corruption. Switching transients: By definition, this is an instantaneous undervoltage. Normal duration of this anomaly is less than a 'voltage spike', typically in the range of nanoseconds. Damage may be incurred in both hardware and software, resulting in burned circuitry, component stress or failure, memory and data losses. Harmonic Distortion: Harmonic distortion is the distortion of the normal line waveform. Harmonic distortion is, generally, transmitted by nonlinear loads. Harmonics are a definitive presence in power. Their distortions can be caused by mundane and ubiquitous equipment found in any pharmaceutical plant. Switch mode power supplies, variable speed motors and drives, copiers, fax machines, variable speed pumps are examples of non-linear loads. Harmonic distortions can cause communication errors, overheating, and hardware damage. Common maladies and failures are CPU clock errors, overheating, and premature failure of electrical components.

Conditioned power All of the previous described conditions are inherent in an unconditioned or raw power supply. A UPS system is a device for the supply of conditioned power. Conditioned power by definition is the use of an inverter to continuously supply 100% new, clean and regulated AC power. The UPS isolates the downstream equipment from the power problems described above. We see in Fig. 1, that utility voltage is sporadic, ranging from 212 to 217 volts. The actual supply should be at 208 volts. The UPS output voltage is between 207 and 207.81 and a total spread of 0.8 volts. The UPS voltage is consistent and conditioned. The utility voltage is dynamic and unpredictable. As stated before, the power utility can supply voltage from 192 to 223 and still adhere to their specifications. This overvoltage/ undervoltage situation can have adverse effects on computers, PLCs, controllers, and data storage devices. All UPS systems today use battery back-up systems to supply power when the utility power fails. Many pharmaceutical facilities also employ generators. Generator activation due to a utility outage is typically a 10-30 second time delay before power is restored. This means, without a UPS system, all of the equipment will be either shutdown or off-line for the duration, from the instant of the power outage until the release of power from the generator. This short duration of power loss can have catastrophic consequences in the pharmaceutical processing areas, laboratory testing facilities, data management, archiving, and acquisition devices. In a previous article1, downtime calculations were displayed showing the loss of business revenue and the consequent liabilities. The value of continuous uptime cannot be underestimated, as it affects and benefits throughput, product quality, quality of manufacturing and formulation, quality assurance, quality of data acquisition, archival and retrieval functions, and the quality of internal business delivery. Uninterruptible pharmaceutical processing, manufacturing and business operations can only be attained with uninterruptible power. UPS systems supply and maintain continuous conditioned power removing the ills of the utility's raw power.

Installation for pharmaceuticals The power usage in a pharmaceutical facility is divided into two unique paths – mission-critical power and non-critical power. Mission-critical power is supplied to uninterruptible operations, processes, and systems. Many pharmaceutical production facilities have 24/7 operations. The biotechnology sector is a prime example of uninterruptible and mission-critical operations. Fermentation, typically of three weeks' duration, needs process parameters to be tightly controlled and monitored; any deviation from the proper parameter readings will significantly or permanently impair the product. Fig. 2 shows an electrical one-line, delineating the power paths in mission-critical and non-critical operations. The red lines denote mission-critical power and the black lines non-critical power. The power utility feed is the first-step in the power train. The utility feed connects to a high voltage switchboard. This switchboard monitors the power usage and distributes to the downstream power train. An automatic transfer switch (ATS) is installed to direct the power either from the utility feed source or from the generator. When a power outage occurs, the ATS changes position to allow the generator to feed the power train. The UPS transmits conditioned power to either distribution boards or to power distribution units (PDUs). These distribution panels transmit the power to individual circuits and to downstream equipment, devices, process equipment, computers, etc. As described previously, in case of a power loss or outage, the generator is activated to provide interim power until the utility power is re-established. The generator power runs to the ATS. The ATS sends the power to the UPS and the rest of the power train. By installing a UPS, two major problems are averted. First, the power supplied to process equipment and computers will always be conditioned power. Second, the power supply time lag due to the start of the generator is eliminated. Generators do not provide conditioned power and should not be used in lieu of an UPS. Generators and UPSs are complementary components in the mission-critical power train. Figs. 3, 4 and 5 describe the UPS output voltage supply during a power outage. The input voltage and output voltage of the UPS are identified with the black and blue traces. The time increment on Fig. 3 is 1 hour and 54 minutes. Fig. 4 elucidates the failure of the input voltage from the utility at 5:53pm on May 28 2003. The yellow line shows the exact instance of the power failure with input voltage drop to 0. The UPS output voltage remains unaffected at 207 volts. Fig. 5 depicts the re-established supply of power at 6.53pm and the jump of voltage from 0 to 212. During the outage, the UPS provided continuous power at 207 volts with no interruption of service. All computer, process and telecom functions remained on-line and in-service with no data loss or corruption. Most importantly, there was no loss of business.

Summary Utility power supply can vary greatly. Overvoltage, undervoltage, surges, sags, harmonics, electrical line noise, transients, lightning etc. are potential power problems that can induce damage to computers, controllers, PLCs, microprocessors, and circuitry. UPS systems will negate the utility power problems and supply continuous on-line conditioned power to all downstream equipment. They should be installed on all mission-critical circuits servicing mission-critical equipment and processes. Generators and UPS systems should be installed as complementary technology.