Regular Instant Voltage drop in a large warehouse facility! 1

[mjawhary]

I am working on a power failure issue at a big warehouse distribution facility in NY. I posted on the site a while ago regarding finding a solution for the power brownouts they have been having that caused the forklift chargers to fail. I recommended using the FLUKE 175 to record power parameters for a period of a week, the data results came back and it shows that they had one incident of a voltage drop on two phases from 277VRMS to 120VRMS, the drop was instantly and then came back to normal, this caused power failures and caused the current to spike. Other than this voltage fluctuation ranged from 275VRMS TO 288RMS max during that week and I think it is normal. I am trying to find the best and more economical solution for this matter, I called the power company before and they said that they didn't report any brownouts or power issues in that area!

Thank you ,

 

[Skogsgurra]

You probably meant Jeff.

I am the one that doesn't understand the measurements. A 'square' dip three seconds long is not normal at all. I still think that the measurements are wrong. I have asked a few times how fast that 175 (now 1750) is sampling. Perhaps every third second?

If that is so, you can have lots and lots of those dips, but sampling and dip coincides only now and then. So, the conclusions may be all wrong. There are many more of them and the duration is much shorter.

Gunnar Englund

http://www.gke.org

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Half full - Half empty? I don't mind. It's what in it that counts.

 

[itsmoked]

Woops! You're right.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[waross]

The reason that I asked about salt water:
I had a customer complaining about an Automatic Transfer Switch.
There were two problems.
1 The watchman/gardener/handyman spent a lot of time sitting in a chair against the wall. From time to time the ATS would "thump". He would report the thump to the owner.
After some conversations with a utility engineer, I found out that during the summer months salt spray would build up on the insulators on the distribution lines near the beach. This time of year, the humidity would increase and the formerly bone dry salt film would absorb moisture and insulators would randomly flash over. Whenever there was a flash over, there would be a voltage dip throughout the system. The ATS was contactor based and the contactor would drop and pull back in with a thump. No damage was done. The best solution was to move the chair.

I asked about your system topology. Determining the system layout and then moving the measuring point helps to determine whether the problem is local or utility based.

Gunnar:
Measurement type True rms (one cycle calculation by overlapping each half cycle - voltage between lines is measured for 3P3W lines and phase voltage is measured for 3P4W lines)
Displayed data Amplitude and duration of dip or interruption
Measurement Same as rms voltage

If it does what it says. It is a Fluke. grin


Bill
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"Why not the best?"
Jimmy Carter