Frequently Asked Questions:
Power Quality or Power Treatment? RxMS answers:
What is Power Quality?
Clean power results in electricity that supplies your operations smoothly. However, dirty power, or poor power quality will cause your machinery and equipment to run roughly and can cause it to shutdown.
Hospitals, printing companies, OEM manufacturers, and just about anyone else in a building can be suffer from poor power quality. The computers being used, the machinery in operation, and even the lighting in a facility can compromise the quality of the power being supplied to your crucial operations. Some of the common symptoms of poor power quality that can have an impact on operation of your equipment include:
- Flickering lights
- Machinery not operating correctly
- Machinery locks-up during operation
- Machinery randomly shuts down
- Poor image quality
- Distortion on monitoring screens
Poor power quality can be caused by a number of things, such as: bad weather, animals, trees, and car accidents. These power quality factors outside of your facility typically occur 8 times per year in your demographic area. Each time your system goes down, money is lost due to missed sales, employee productivity loss, damaged equipment, and scrap materials. However, these are losses caused by events outside your building. However, the majority of events are actually caused by factors inside your walls.
Poor grounding, improper wiring, static electricity (environmental factors), lighting, and other equipment all cause the majority of power quality problems inside your facility. They can often create disturbances with your equipment like those stated above. Most companies are usually unaware that there are solutions to these problems.
What is a Voltage Transient?
A Voltage Transient is a momentary change in the voltage or current over a very short amount of time. The short time interval is less than 1 cycle (16 milliseconds). Transients are most often measured in microseconds rather than milliseconds. A Voltage Transient is usually referred to as a "Spike." A Voltage Transient has a separate beginning and end, and it may occur often or at regular intervals. Another regard of Voltage Transients is if they are impulsive, or oscillatory, which refers to the shape of the transient. If there is a Voltage Transient, and the voltage returns to its full value, then the Voltage Transient is defined as "Impulsive." On the other hand, if the Voltage Transient bounces around (becoming smaller at each bounce), then the Voltage Transient is defined as an Oscillatory Transient because it "rings," or oscillates.
What is a Voltage Sag or Voltage Swell?
A Voltage Sag is a reduction in the A/C voltage, and a Voltage Swell is an increase in the A/C voltage, with a duration which may range from a half-cycle to a few seconds.
What is a UPS?
A UPS (Uninterruptible Power Supply), is a device that provides uninterrupted power to the system that is connected to the load (regardless of the input power being supplied). UPS systems come in a wide array of classifications and amplitudes. The selection of a UPS is heavily dependent upon what kind of load you have and how big it is. There are also many other critical things to evaluate when you are considering a UPS.
Will testing the power quality repair the problems that I am having?
No it will not. Conducting a site survey will assist you in pinpointing your problem, and also point you in the right direction to get the problem solved. Rx Monitoring Services is a third-party, unbiased service that will not only help you identify your problem, but also work with you to make it go away for good!
If I have a power conditioner or a UPS why do I need to monitor?
Having a power conditioner on site does not automatically mean that your site will be trouble free from power quality issues. While having it should help reduce the chances there are still several issues that need to be documented:
- If the customer bought the conditioner from the manufacturer than the manufacturer assumes the liability for all power issues (at least in the customer’s mind) and the site may have issues that the unit is not designed to fix.
- The protection unit is assume to be working correctly and arrived without shipping damage and was installed correctly (some manufacturers ship their unit in by-pass and RxMS has detected that prior to an actual issue!).
- Not all units protect against everything. Many sites that RxMS has surveyed found that the UPS (or voltage regulator) solved the voltage issue but there are still ground issues. While other sited have sent hat the hospital power and the UPS are actually “fighting” each other and therefore there is a highly unstable situation. This “over medication” is dangerous because it is generally assumed that the power is ok so it takes months of inconvenience and lots of hours (and dollars) spent on site to find out that the issue was a basic one!
- The adding on of option or sometime new software can often change the way the system draws power. Many RxMS customers have seen that by adding a new procedure the current draw may be increased enough to cause an issue with the existing system. Since the power is assumed good and the software upgrade is new, it gets all of the attention and it becomes a time involved frustrating ordeal.
I only care about voltage – why should I connect the current probes?
Connecting the current probes provides valuable information that is required to adequately prescribe a solution to the site’s issues. The current gives the engineer information on how the system reacted to the event. This is especial key to low frequency events (e.g. Power Factor Correction Impulses) so that the severity of the issue can be determined. It also tells us the usage pattern for the equipment that is key to understanding how and when the system is used.
You sent me the wrong plug. Should I send the entire unit back?
No! Immediately call RxMS and describe the plug required (NEMA number, voltage and current rating, etc.) and a customer service representative will FedEx you a new AC Adapter that same day. Simply return the adapters when the survey is over. An additional time will added to your account so that you can still adequately survey the site.
I need to monitor temperature and humidity in the control room but the power gets monitored in the equipment room. How does this get done?
Call RxMS to order the EL-50 which is a separate Environmental logger (temperature, humidity, air pressure, and dust) that records in memory as well as displays the reading on the screen so that the probe can be properly placed in the room. This monitoring device can be ordered separately.
Isn’t RxMS biased?
The unique part of RxMS’s business plan is that it receives no revenue from power protection manufacturers or distributors. RxMS is employed by clients to document the facts and is available (at no extra charge) to review the findings with the customer in order to help them understand and find a quick and complete resolution to the issues through any means; inspection, adding protection or eliminating a know cause of the events documented (e.g. shutting the system off at night to avoid the nightly issues). RxMS works the same as a CSI in that it only works with the facts provided and uses it’s expertise to prescribe corrective actions (if required). Often the result in the survey finds an internal issue. Our current estimates are that our clients find about 32% of issues are internally generated.
How do I determine which direction to put the current probe?
The direction of the arrow on the current probe should be in the direction of the current flow. For a three phase system, the phases should have the arrow of the probe facing the input to the breaker (if on the input to the main panel) or if on the out of the circuit breaker, the arrow should be facing away from the breaker and towards the load. The Neutral should be facing toward the Neutral bar. The direction of the ground current probe doesn’t matter as there hopefully isn’t any current flowing and if there is, it would be a 50-50 guess as to which way it’s flowing. Anyway, the direction of the current can be adjusted on the report side by RxMS in most sections of the report.
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