Checking PFC capacitors.

Pete999 · Jul 7, 2017

LankyWill said:
What's a PFC unit?

Private First Class US Army

as in PFC LankyWill or PFC Pete999 Sorry couldn't resist

Tiny Spark · Jul 7, 2017

Pete999 said:
Private First Class US Army as in PFC LankyWill or PFC Pete999 Sorry couldn't resist

[ElectriciansForums.net] Checking PFC capacitors.

Tiny Spark · Jul 7, 2017

Well heres a pic of what ime working with, may be of interest to those who have not seen inside one before.

On a technical note though, I put a few clamps on dead then energised the system to see what sort of Amps I was getting on some of the stages.

I got one at 42A which is obv low and one at 63A.

What sort of tolerances would be exceptable? 10%??

Had a chat with the boss and I think we will go down the road of getting some VDE gloves, masks etc and just testing them live with the clamp meter as mentioned above.

Thanks for the help guys, Ive been off a while but glad to see everyone is still ticking over on here even if its dead on tapatalk!!

UKMeterman · Jul 8, 2017

One way to keep an eye on the unit would be to install a modbus based power quality anyliser, these are about £200 for the main unit and then the CTs on top. Then you could monitor the current in all three phases remotely when it is in auto or manual mode. It may be possible with a suitable computer to trigger an alarm when things get seriously out of spec.

As for live testing readup on arc flash....

Tiny Spark · Jul 10, 2017

UKMeterman said:
One way to keep an eye on the unit would be to install a modbus based power quality anyliser, these are about £200 for the main unit and then the CTs on top. Then you could monitor the current in all three phases remotely when it is in auto or manual mode. It may be possible with a suitable computer to trigger an alarm when things get seriously out of spec.

As for live testing readup on arc flash....

I need to measure each stage individually though not just the main 3 phases.

So potentulially up to 36 seperate phases per unit.

As for Arc flash yeah nasty stuff.

ex 2 Base · Jan 14, 2018

Using three Cts an ammeter and a make before break rotary switch you could have a permanent system for monitoring the KVAr. I respectfully suggest you have a second person standing by whilst you are carrying out live working using a clamp type meter with cabinet door open.

David Prosser · Feb 2, 2018

I would not be working(or testing) in that panel live at all definitely not to IP2X standards. Very easy to brush up against live bars even with suitable gloves the upper arm and shoulders would most likely at some point be inside the panel.
Maybe just get ABB in to show you how to test them safely.

bcm_spark · Mar 9, 2018

Not read all the thread but we get a firm in, I think most recent quote was about 250 quid but they are only down the road. Our PFC unit takes care of hell of lot of motors as well. If you want I'll get their details Monday