PFC Capacitor with Backup Generator as Voltage Regulator

[scm305]

Does it make sense to use a PFC capacitor bank to maintain my household voltage level when using a generator of about 8.5kVA on my 200 amp electrical service? I have a 3/4 HP well pump and a 3 ton central air unit along with the rest of the usual appliances running on this service. Lights dim momentarily when pump or air comes on. Also are there any risks associated with doing this. I would placard my meter base so utility workers would be aware.

 

[davidbeach]

Just accept the voltage sag.

 

[wayne440]

Capacitor or no, an 8.5kw generator is not going to be as stiff as typical utility power.

 

[jraef]

PFC caps would not prevent the voltage sag anyway. Either live with it as davidbeach said, or install a Soft Starer or VFD on the well pump. That may be problematic for 1 phase loads however and the largest being an A/C compressor may make it impossible anyway.

By the way, the "quick and dirty rule of thumb" on generator sizing when starting motors across-the-line is kVA = 3x connected HP. You have almost 4HP connected to that generator, you should have bought a 12kVA. You are not going to avoid a sag when they start and if they start at exactly the same time, it may not happen at all.

"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
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[waross]

I would placard my meter base so utility workers would be aware.

This is unacceptable and dangerous. It could have serious legal repercussions for you, even if there are no incidents. In the worst case scenario you may be responsible for the death of a utility worker.
Please have a qualified electrician install an aproved transfer switch.
Adding capacitors to a generator may lead to over-voltages and instability and possible damage to the generator and to connected equipment.
As far as the motors, if they are starting, re-read David Beach's post concerning the voltage dip.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[HamidEle]

Suggest to ask for the generator reactive capability curve to see the generator capability. Try to avoid capacitor in the generator system. You would experience some difficulties.