Power Leakage from DC Power Supply

[K6CCC]

Just for additional giggles and grins, your electric utility definitely cares about power factor. Bad power factor "consumes" capacity in generators, transformers, and transmission lines. Your utility refers to it as "Volt Ampere Reactance" of VARs. For the most part the electric system load is inductive (mostly due to induction motors). As a result, utilities install capacitors on lines both on high voltage transmission lines and more commonly on distribution lines. Often those are switchable so they can be added or not as needed. For larger commercial / industrial customers, power factor is measured and factored into billing. For residential, the meters are less sophisticated and generally you are not billed for crappy power factor.

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[chl]

Yes some, but not apparently all utilities, charge commercial users a power factor surcharge based on VARs because highly reactive loads require greater current flow which results in greater I2R losses in the utility supply lines as well as requiring greater utility capacity.

However, where utilities charge that way, commercial users generally install their own reactance compensating/power factor correction circuitry to minimize or eliminate any VAR charge by bring their power factor closer to 1. And the VAR charge incentivizes them to do so.

Besides reducing the VAR charges $, PF correction also improves efficiency (less wasted energy/losses with lower currents) and reduce the wear and tear higher currents can cause to the infrastructure which all users pay for eventually.

BTW, correcting the power factor of a motor, for example, can make it last longer by reducing current and heat stress and eliminating voltage surges and falls, as well as minimizing the energy lost to heat.

While VAR charges are generally not specifically charged to residential users, they may/do contribute to things you ARE charged for like distribution charges (wires, transformers, etc.) and the costs of new infrastructure, plants, etc. needed to meet the capacity requirements which are greater when there are uncorrected reactive loads.

Just more FYI related to PF.

 

[bmwhitetx]

What wattmeter are you using? Is on the AC side (120V input) of your power supply - something like this? And what is the make and model of your DC power supply?

 

[richguy82]

What wattmeter are you using? Is on the AC side (120V input) of your power supply - something like this? And what is the make and model of your DC power supply?

Yes, I was using a similar watt meter. Here is the power supply. https://a.co/d/2bxTxbQ

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