What is power factor, and why does it matter?

Power factor compares the power doing useful work with the total power the system has to supply. A value of 1.0 means all of it is working. Lower numbers mean the conductors, transformers and the service are carrying current that does no work, and that current takes up capacity you may be paying for.

Motors, transformers that run lightly loaded and some electronic loads pull the number down. Some commercial rate plans add a charge when power factor falls below a set level, so it is worth knowing where your building stands.

What is voltage stability?

It is how steadily the voltage at your equipment stays near its rated value. ANSI C84.1 sets the normal service voltage range at plus or minus 5 percent of nominal. Outside that range, motors run hot, electronics reset and lights flicker. Heavy summer loads on a long run of conductor can pull voltage down at the far end of a building.

What do we measure and report?

  • Power factor over time, at the service and at selected panels
  • Voltage minimum, maximum and average, with sag and swell events
  • Phase balance on three-phase systems
  • Harmonic distortion where electronic loads are present
  • Peak demand during the recording period

What can come out of the assessment?

If power factor is low, the report says where it is low and what could raise it, such as capacitor correction sized to the measured load. Capacitors can interact badly with harmonics, which is why we measure harmonics before recommending one. If voltage is out of range, the report points to the location and the likely cause, such as an undersized feeder, a poor connection or heavy load on a shared transformer.

How is this different from troubleshooting a specific problem?

This is a baseline assessment of the whole system, useful before you add equipment or when an owner wants to know the condition of the power. If a particular machine keeps failing or breakers keep tripping, power monitoring is built for that. The overall service is described on our Electrical Load Studies page.

Arizona ROC #153656 (CR-11) | Over 40 years in business

OUR PROCESS

HOW DOES A JOB WITH PHOENIX CONTRACTING SERVICES WORK?

Every job follows three steps: a site walkthrough, testing and documentation, then findings and next steps.

01

WALKTHROUGH AND SCOPE

We start with a free phone consultation, and you can send a photo of your panel or equipment. If on-site work is needed, we visit, look at the panels and service, and agree on what needs to be tested or repaired before any work starts. On-site work is quoted before it begins.

02

TESTING AND DOCUMENTATION

Load loggers and a thermal camera record what the equipment is doing, and the results are documented for each panel or component we check.

03

FINDINGS AND NEXT STEPS

We go over what we found and your options in plain language. If corrective work is needed, we are licensed to do it.

WHAT CUSTOMERS SAY ABOUT US

5.0 VERIFIED GOOGLE RATING
Jeff and his team were amazing! I needed a load calculation, one line diagram, and a panel schedule for an electrical permit with the city. Phoenix Contracting Services had an unbeatable price and moved quickly to See more
Jeff’s knowledge, experience and professionalism are exemplary! We contracted him to provide engineering plans to permit our relocation and upgrade of electrical service meter. He worked with my electricians on details See more
We woke to a Friday morning with weird lighting fluctuations. I checked the service panel to find a burning smell and melted bus bar under AC breaker. Since bus bar was melted, I contacted SRP who provided some certified See more

What is a good power factor?
Closer to 1.0 is better. Many utilities and rate plans look for 0.9 or better. We report where you are and what is driving the number.
Can low power factor raise my bill?
On some commercial rate plans, yes. Check your plan with APS or SRP. Our report gives you the measured numbers to compare against it.
What causes voltage to drop?
Heavy load on a long conductor, an undersized feeder, a loose connection or a crowded transformer. The recording shows when and where it drops.
Do you install power factor correction?
We can quote and install correction equipment after measuring. We check harmonics first, because capacitors and harmonics can interact.
How long does the recording take?
Usually 7 to 30 days, so it catches a full range of operation, including peak days.

Tell Us What Your Electrical System Needs

Share the details of your project, and our team will help you identify the most practical next step.