Working on a complex PF penalty dispute with PPL Electric here in Harrisburg. It's a 275-bed hospital on Rate Schedule GS-Large with monthly demand around 2,800 kW. They've been paying PF penalties averaging $3,200/month for the past two years. The facility has automatic correction equipment that should maintain 0.95+ PF, but PPL claims they're seeing 0.84-0.87 monthly averages. Hospital engineering insists their system is working properly and shows good power factor on their monitoring equipment. This smells like a metering or measurement timing issue to me.
PPL Electric - Disputed PF penalties on hospital account
Sylvia, hospitals are tricky for PF measurement because of all the non-linear loads. MRI machines, X-ray equipment, and LED lighting create harmonics that can confuse older revenue meters. Has PPL upgraded to newer meters that account for harmonic distortion? Also, automatic correction systems can malfunction or become untuned over time. When was the cap bank last serviced and tested?
Terry, good points about harmonics. The hospital has a lot of electronic equipment that wasn't there when the correction system was originally designed in 2008. PPL did upgrade their meter about 18 months ago to a new Itron model. The timing correlates with when the PF penalties started appearing consistently. The cap bank was last serviced in 2014, so it's definitely due for inspection and possible retuning.
Sylvia, I had a similar issue with Georgia Power and a data center. The new smart meters measure true power factor including harmonic effects, while the old electromechanical meters only saw fundamental frequency PF. The difference can be significant with modern electronic loads. You might need harmonic filtering along with traditional capacitive correction. Also check if the hospital added any major equipment like new imaging systems or LED retrofits around the time penalties started.
Rachel, that's exactly what I suspected about the meter change. The hospital did complete a major LED lighting retrofit in early 2015, which would explain the increased harmonic content. They also added two new CT scanners. I'm recommending a comprehensive power quality audit to identify harmonic sources and determine if they need active filtering or just cap bank retuning.
Hospitals are notorious for power quality issues. JEA requires harmonic studies for any medical facility over 1 MW. The correction equipment needs to handle both displacement and distortion power factor. Traditional cap banks can actually make harmonics worse if they create resonance with the facility's electronic loads. Definitely recommend active filtering for this application.
Rob's absolutely right about resonance issues. I've seen cap banks create harmonic amplification in hospitals that actually made the power factor worse. Before spending money on new equipment, I'd recommend temporary disconnection of the existing cap bank to see if PF improves. Sometimes removing old correction equipment is the first step toward a proper solution.
Update: Had the electrical contractor disable the cap bank last week and PPL's next meter reading showed 0.79 PF, which is worse than the 0.84-0.87 they were claiming. This confirms the cap bank is providing some correction but not enough. The uncorrected PF suggests significant harmonic distortion from all the electronic medical equipment. Moving forward with active harmonic filtering recommendation.
Sylvia, what's the total harmonic distortion reading on the current? That will help size the active filter properly. Most hospital applications I've seen need 200-400A of active filtering capacity. The payback is usually 18-24 months when you factor in both PF penalty savings and improved power quality for sensitive medical equipment.
Glen, we measured THD-I at about 22% on the main service entrance. The electrical engineer is recommending a 300A active filter with built-in PF correction. Estimated cost is $75,000 installed, which should pay for itself in about 20 months based on current penalty levels. The hospital is also interested in the power quality benefits for their critical care equipment.
That THD level definitely explains the PF issues. 22% current distortion will significantly impact displacement power factor correction. The active filter approach is the right solution. Make sure the contractor programs it properly for the hospital's load profile. These systems need periodic tuning as equipment loads change over time.
Ed's point about programming is critical. I've seen active filters that weren't properly commissioned and actually made power quality worse. The hospital should also consider whether they want the system to prioritize harmonic filtering or power factor correction during different operating modes. Emergency generator operation might require different settings than normal utility service.
Great point about generator operation Juan. The hospital has a 1.5 MW backup generator that runs monthly tests plus emergency situations. I'll make sure the active filter specification includes proper coordination with generator operation. The last thing we want is power quality issues during emergency power situations.
Final update: Active filter installation completed last month and first full billing cycle shows 0.96 PF average. PPL penalty dropped from $3,200 to zero. Hospital engineering is also reporting better equipment performance and fewer nuisance trips on sensitive circuits. Total project cost was $78,500 and should pay back in 18 months. Thanks everyone for the technical guidance on this challenging application.