hospital-blog

As of 2019, healthcare facilities in the US make up less than 5% of the total area in the commercial sector but consume over 10% of the total power (MDPI Energies Journal) and have to pay those bills.  In addition, advanced medical technology has increasingly sensitive power quality requirements. For those tasked with keeping the lights (and life-saving machines) running, having a dependable power quality analyzer on hand has tremendous benefits.

Briefly, a power analyzer is a power testing instrument that measures a wide range of power components, like voltage, current, frequency, harmonics, energy, etc. A power-quality analyzer does all those things and also captures power quality events like swell, dip, transients, inrush, etc. Here are the seven key reasons why every hospital should own at least one good power-quality analyzer.

1. Ampacity and Load Verification

Whenever you want to add new equipment or even new outlets, you should be performing a (minimum) 72-hour power study to be sure that you can safely add the new load to the existing load. This study can be done easily with a power quality analyzer and it is often a legal requirement. Such studies are done for a reason, and knowing whether or not a new load will introduce problems is a critical piece of information for a healthcare facility that cannot afford to have equipment suddenly shut down. Ideally, once the study is complete, you will want to quickly generate a concise and informative report, investing a minimum of effort and time to create it. A report writing feature should be part of the software supplied with the analyzer.

 

2. Evaluate the Quality of Power at Any Point

Advanced medical equipment may be quite sensitive to problems with the supplied power. You will want to be able to not only log the ongoing voltage and power delivered, but also to trigger on unusual events to see what was occurring when equipment malfunctioned. Preferably, you will want to have detailed sub-second information in several views in order for the cause of a malfunction to be identified. Surface-level power analysis is helpful but a power quality analyzer allows you to look deeper into the root cause of any power issue that may arise. Detecting power quality concerns early may also have a big impact on extending the useful life of a piece of equipment. You may also find it advantageous to test multiple distribution panels or tools at one time to compare activity between them and get a greater view of the power quality throughout the facility. Be sure the supplied software can display power quality events in multiple views.

 

3. Verify and Evaluate Backup Power

Life-support equipment demands immediate power backup when utility power fails. The pass-off from battery power to diesel generators must similarly occur without interruption or surge. Finally, when utility power returns, the synchronization of phase and magnitude of the generated power must be sufficiently close to the restored utility power to avoid interruption or surge. A power analyzer can record the general timing and magnitudes of the transfers, but a power quality analyzer is needed to capture the electronic signatures and sub-second timing at the moments of transfer to see problems and ascertain the source of any issue.

 

4. Evaluate Inrush Current

When breakers trip unexpectedly or equipment takes itself offline for no apparent reason, triggered capture of inrush current can reveal a signature that reveals if the problem is due to momentary excess current or to degraded breakers. It can also convincingly identify which equipment is the source of excessive inrush. Be sure the supplied software can provide ½ cycle RMS profiles of the inrush current to judge its characteristics.

 

5. Evaluate Harmonic Distortion of Power

Modern electronic equipment often introduces harmonics into the power system. Although any one device rarely causes issues for other equipment or to the power delivery system, when there are many loads generating harmonics, safety issues can arise. Specifically:

  • some sensitive electronic equipment may have limits on the allowed harmonics of the delivered power,
  • harmonic currents can cause unforeseen heating in walls and raceways, or
  • harmonic currents will lower the load delivery capacity of the distributed power at your facility and can cause unsafe heating in the transformers. Excessive heating, as every facility director would know, leads to the possibility for fires and/or early equipment breakdown/malfunction.

6. Reduce Power Costs and Perform Cost-Benefit Analysis

Evaluate the cost of power to existing equipment and the projected savings that come from replacement technology. With the cost of power being a large recurring cost of operations, getting the knowledge you need to shave a few percent from these on-going charges can quickly pay for your power quality analyzer. But first, you need to evaluate what the present costs are versus the actual benefits of replacement technology while in use. Be sure the software includes a report-generating wizard that presents before/after projected savings in both dollars and demand. This be key in making or justifying the correct decision. Furthermore, a power quality analyzer can identify the electrical equipment drawing the most power. Knowing where and how much power is delivered is invaluable knowledge that can help healthcare facilities save money on their electricity bill, freeing up more money towards saving lives.

7. Special Needs

  1. If certain equipment, such as high-resolution imaging instruments, require highly filtered voltage you may benefit from an analyzer that can measure the high frequency content of the power-line, above normal harmonic levels. The ability to measure the high frequency content of the power-line far above normal harmonic levels, up to 100,000 Hz, can provide a view of potential degradation wired directly into the equipment.
  2. If you manage your own distribution transformers, it can be beneficial to measure the medium voltage input to the transformers, typically 12,500 volts. If you can connect your analyzer directly to that high voltage, you can measure harmonics and sub-cycle transient events that may not pass through permanently-mounted PTs and metering step-down circuits.
  3. Similarly, it is not uncommon to operate 4,160 V motors in a high-power, high-efficiency operation. The ability to connect directly to 4,160 V can be very beneficial in evaluating the operation of the motor.
  4. If your facility includes DC equipment or battery banks, be sure your power analyzer has the adapters and range to cover the scale of your DC voltage and current needs.
  5. Advanced triggering abilities. Most power quality issues can be identified with half-cycle evaluation, but when you need special abilities, it is good to have them ready and waiting in your test equipment. The ability to trigger on non-cyclical events, such as switching transients or generated spikes of defective equipment, can solve finger-pointing controversies quickly and convincingly.

References:

Bawaneh K, Nezami F, Rasheduzzaman Md., Deken B. Energy Consumption Analysis and Characterization of Healthcare Facilities in the United States. MDPI. 2019. https://www.mdpi.com/1996-1073/12/19/3775/pdf