You might already be utilizing predictive upkeep (PdM) strategies in your motors and drives. However how usually do you examine the ability to your gear? By including fundamental energy high quality measurements to manufacturing gear upkeep procedures you’ll be able to head off surprising failures in each manufacturing gear and your energy system lg صيانة الجي.
Price financial savings
Insurance coverage claims information within the NFPA 70B upkeep customary reveals that roughly half of the fee related to electrical failures could possibly be prevented by common upkeep. A research printed in IEEE 493-1997 says poorly maintained system can attribute 49 % of its failures to lack of upkeep.
To find out the price of a failure, it helps to think about three key classes:
• Misplaced earnings (gross margin) attributable to downtime
• Price of labor to troubleshoot, patch, clear up, restore and restart
• Price of broken gear and supplies, together with repairs, replacements and scrapped materials
Integrating energy high quality into PdM
Not like a complete electrical system survey, predictive upkeep energy high quality focuses on a small set of measurements that may predict energy distribution or vital load failures. By checking the ability high quality at vital masses, you see the impact of system as much as the load. Your predictive upkeep inspection route most likely already contains any motors, turbines, pumps, A/C models, followers, gearboxes, or chillers on website.
Voltage stability, harmonic distortion, and unbalance are good indicators of load and distribution system well being and might be taken and recorded rapidly with little incremental labor. Present measurements can establish adjustments in the way in which the load is drawing. All of those measurements might be taken with out halting operations and generate numbers that may simply be entered into upkeep software program and plotted over time.
For every measurement level or piece of apparatus, decide what restrict ought to set off corrective motion. Limits ought to be set effectively beneath the purpose of failure, and as time goes on limits could also be “tightened” or “loosened” by analyzing historic information. The suitable limits rely considerably on the power of your masses to take care of energy variation. However for many gear, your upkeep crew can devise a set of default, “home limits” based mostly on business requirements and expertise.
The price of three-phase energy analyzers is decrease now than ever and it ought to solely take roughly 15 minutes to take the readings mentioned on this article. (Storing voltage sag information will add extra time, because it requires choosing up the information after a day or so.)
Good voltage degree and stability are elementary necessities for dependable gear operation.
• Operating masses at overly excessive or low voltages causes reliability issues and failures. Confirm that line voltage is inside 10 % of the nameplate score.
• As connections in your system deteriorate, the rising impedance will trigger “insulation resistance drops” in voltage. Added masses, particularly these with excessive inrush, will even trigger voltage decline over time. The masses farthest from the service entrance or transformer will present the bottom voltage.
• Impartial to floor voltage tells you the way closely your system is loaded and helps you observe harmonic present. Impartial to floor voltage increased than three% ought to set off additional investigation.
Voltage sag rely
Taking a single voltage studying tells solely a part of the story. How is the voltage altering throughout an hour? Throughout a day? Sags, swells and transients are short-term variations in voltage. The voltage sag (or dip) is the most typical and troublesome selection.
Sags point out system is having bother responding to load necessities and important sags can interrupt manufacturing. Voltage sags may cause spurious resets on digital gear comparable to computer systems or controllers, and a sag on one section may cause the opposite two to overcompensate, doubtlessly tripping the circuit.
Sags have a number of dimensions: depth, period, and time of day. Utilities use a particular index to trace the variety of sags that happen over a time frame. To gauge the depth of the sags, they rely how usually voltage drops beneath varied thresholds.
The longer and bigger the voltage variations, the extra doubtless gear is to malfunction. For instance, the Data Know-how Trade Council (ITIC) curve specifies that 120 V laptop gear ought to be capable to run so long as voltage doesn’t drop beneath 96 V for greater than 10 seconds or beneath 84 V for greater than zero.5 seconds.
Present measurements that development upward are a key indicator of an issue or degradation in your load. Whereas gear is working, monitor section, impartial and floor present over time. Be sure that not one of the currents are growing considerably, confirm that they are lower than the nameplate score, and preserve a watch out for top impartial present, which may point out harmonics and unbalance.