Before fixing a problem in a building's electrical distribution system, we need to identify and locate the electrical problem. And one way to figure out what has gone wrong is to do an electrical load monitoring test to collect data on power quality, quantity used and sometimes harmonic data.
Electrical load monitoring is done when:
An electrical load monitoring test taking place in Calgary. The recording device stores real-time data for up to a month.
- Adding to an existing system,
- Verifying the amount of electricity consumed,
- As a part of an electrical distribution system assessment to investigate over-load conditions, voltage drops, load imbalance between the phases, power factor, load profiles and harmonic distortion problems. One of these issues can cause intermittent problems that can cause strange equipment operations, unexpected failures and a whole lot of operational headaches!
Do I need an Electrical Load Monitoring Test?
Understanding your existing electrical loads is required to verify the capacity of the electrical system in your building. The conductors are required by the Canadian Electrical Code (Tables 1 to 4) to carry up to a specific amount of current to ensure safety and reliability. From there, we can determine:
- the accurate amount of energy usage,
- see if there is excess capacity in the existing system,
- determine when and how energy is being used,
- where costs can be cut down.
As a part of a preventative electrical maintenance program, building owners can:
- lower the cost of additional upgrades,
- lower operating costs,
- prevent costly and inconvenient outages,
- extend maintenance programs instead of prematurely replacing expensive equipment,
- improve reliability,
- increase assurance and having peace-of-mind that the electrical system is safe, sound and operating as expected.
When to Seek Help for your Electrical Distribution System?
Similar to your car, electrical and electronic equipment may degrade over time. You may notice:
- Your electrical bills are higher,
- Equipment running hotter than usual,
- Motors may make strange noises, indicating a pending problem,
- Erratic and seemingly unrelated equipment failures throughout the building.
As professional engineers and problem solvers, the hardest problems to solve is when deteriorating equipment causes other equipment on the circuit to fail! The real culprit is camouflaged by the other masquerading failures.
If you're noticing intermittent problems, an electrical load monitoring test may help to identify and isolate the real source of the problem in your building.
Monitoring is done on the main conductors as well as the neutral where unbalanced return current flows back to the source.
How is an Electrical Load Test Done?
We work with our clients to determine how and where to conduct the load monitoring. As electrical consultants, we sometimes recommend real-time testing to help narrow down which piece of equipment is causing the problem. For one client in Vancouver, testing helped to find a voltage drop issue that only occurred at specific times of the day. We were lucky to capture the failure after only 3 hours of monitoring.
We clamp on sensitive instruments to the conductors - sometimes at the incoming main service, other times at feeders to major subsystems - and a recording device monitors the current, voltage and other electrical characteristics. We then compare the actual readings to the electrical load calculation for the circuit or entire facility.
Most commercial buildings in Alberta and BC operate at 120/208 V 3-Phase while 347/600V is used on light-industrial and office buildings. We follow proven engineering procedures to ensure the testing is non-intrusive, accurate and safe.
For computer loads and data equipment racks, we monitor harmonic voltages and currents which can inject these harmful distortions into other equipment on the circuits.
The recording period needs to be long enough to capture a realistic amount of data that is a true representative of the electrical load. Similar to your car, the problem has to be occur before an accurate diagnosis can be made.
The duration depends on many factors including weather (air-conditioners are only used in the summer), production process and interaction between other equipment (i.e. heaters and ventilation motors).
Our goal is to capture the problem in the electrical system as your equipment is in use. Sometimes there are capacity issues, sometimes transients and harmonics.
If we notice feeders with usage over 80% of rated value (continuous current), we make note of the usage, duration and compliance to Canadian code (CEC Section 8).
Our recommendations are compliant to applicable standards while taking into account your business needs, operations and future growth potential.
A electrical load monitoring is one component of power system studies and gives you valuable information on the present state of your electrical distribution system.
Electrical Load Monitoring Report
Once the data has been gathered and collated for a loading profile, a report is generated that includes:
- Voltage and current,
- kW, kVAR, power factor,
- harmonics (if required)
Your report will identify if any conductors are operating at over 80% ampacity for continuous usage as well recommendations to improve reliability and compliance with all national, provincial and local safety codes.
Usually, once the problem is spotted, clients will forego the electrical load monitoring report and opt directly for a realistic resolution that's right for them and their budget.