Is it time for an Energy Audit?

How do you know when it’s time for an Energy Audit or a Power System Study? When was the last time you assessed your Electrical Safety Maintenance Program?

PENTA has put together some questions for you to ask yourself to assess if it’s time for a Power Study, Energy Audit, and/or a total overhaul of your facility’s outdated electrical equipment and systems. Safety is always a priority, but sometimes things like electrical/power gets put on the shelf. Here is a way for you to decide if you have put this aspect of your plant on the shelf for too long.

Q: When was your latest facility-wide power study completed?

It is recommended to update a facility power study at 5-7 year intervals.

A typical facility power study includes the following:

• Demand Load Study
• Load Flow Study
• Transient Motor Starting Analysis
• Short-Circuit Analysis
• Overcurrent Protective Device Coordination Study
• Arc-Flash Hazard Analysis & Labeling
• Harmonic System Study

PENTA utilizes SKM Power*Tools for all power system analysis projects. This software is used by the top 40 Electrical Engineering Firms in the world.

Situations where a power study update may be warranted…

• Q: Do you have high demand charges from your electric utility?
• Q: Are you charged (penalized) for low power factor by your utility?
• Q: Do you occasionally experience low operating voltage that causes abnormal operation?
• Q: Has your plant experienced unplanned downtime due to premature failure of equipment? (i.e. switchgear, transformers, MCC, cables, motors, etc.)
• Q: Does your plant experience repeated nuisance tripping of protective devices or sensitive electronic equipment? Do you suspect this may potentially be caused by high harmonics? (i.e. PLC’s, VFD’s, etc.)
• Q: Does your plant experience unexplained outages that remain unresolved to this day?
• Q: Has your plant experienced main switchgear trips resulting in plantwide outage, that should have been cleared at a lower level in the system?
• Q: Has your facility implemented an Arc-Flash hazard awareness and mitigation program?
• Q: Is all of your equipment labeled for PPE requirements for energized work?
• Q: Has any new equipment been added recently that may warrant review/update of existing Arc-Flash labeling?

The various analyses comprised within an overall power system study, indicated as follows, can be utilized to uncover and root-cause many types of problems within an existing power distribution system

Q: Have you assessed the Demand Load recently?

• Used to calculate the connected, design, and demand loading of components utilized within the power distribution system.
• Necessary to ascertain operating load conditions on the power distribution system equipment, and confirm demand load as billed by the electrical utility.

Q: Have you considered if you need a Load Flow / Motor Starting Analysis?

• To calculate voltage levels and branch current flows to compare to equipment ratings.
• Necessary to uncover potential sources for problems such as:
  a. Transformers running hot
  b. Low operating voltage under normal or motor-starting conditions
  c. Motors failing prematurely

Q: Do you know if you need a Short-Circuit Analysis?

• To calculate maximum available average/peak fault levels for comparison to short-circuit interrupting ratings.
• Necessary to ensure power distribution equipment is being applied and operated within its capability to safely interrupt fault current without strong potential for severe/catastrophic failure. To ensure protective device ratings exceed their calculated fault duties.

Q: When did your facility last conduct an Overcurrent Coordination Study?

This study is executed to ensure the sizing and setting of overcurrent protective devices are made such that…

• Devices are capable of carrying load current and interrupting fault current to promote maximum Life Safety.
• Equipment is Protected from excessive duty and thermal stress.
• Devices are capable of maximum Selectivity such that in response to a fault, the minimum area of the electrical system is removed from service.

Q: Do you know if your facility could benefit from an Arc-Flash Hazard Analysis?

• Used to calculate incident energy levels throughout the power distribution system, as result of the calculated level of available short-circuit current, and the protective device settings initially arrived at during the Overcurrent Coordination Study. Device settings will be optimized to minimize the arc-flash incident energy levels to the extent practical.
• Necessary to identify and label the PPE that must be worn by qualified workers while working on energized equipment.
• Identify and label the arc-flash boundary distance that must be maintained by an unprotected worker from the potential arc source while work is performed.

Power – Equipment / Infrastructure

• Q: What is the age/vintage of your electrical power distribution equipment, motors, VFD’s, etc.?
• Q: Do you have maintenance/operation issues due to aging infrastructure that could be studied for possible improvements?
• Q: Is it time to study/consider upgrade options for improved reliability and uptime?

Power – Efficiency / Consumption Reduction

• Q: Does your facility exhibit high specific power consumption?
• Q: Have you considered undertaking a process/energy audit to uncover potential improvement projects with reasonably short payback periods to decrease power consumption?

Have more questions than answers swimming around in you mind? Contact us so we can answer all your questions or even schedule a consultation. Go to https://www.penta.net/contact-us