230 V electrical problems
230 V electrical problems
(OP)
We have 3to 4 different pieces of equipment running on 230V lines in our building that have got damaged in the last month (all are -80C freezers. Some of the freezers are brand new.
What is the best way to analyze the power? I have a 1000X voltage probe and a few Oscopes and was thinking of taking some FFTs and looking at 60Hz signal (time domain) as well. Does this seem logical?
thanks
Jim






RE: 230 V electrical problems
But far better to use a power analyzer and set trig limits to standard values. That way, you will see when you get transients, brown outs, swells, distortion and all other things that may kill your equipment.
Just looking at the supply when everything is fine usually doesn't help.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: 230 V electrical problems
are there surge suppressors similar to the 120V equipvalents that are sold for 230V 20A?
RE: 230 V electrical problems
Rafiq Bulsara
http://www.srengineersct.com
RE: 230 V electrical problems
thread237-290178: Will coiling 240v 3 ph motor leads cause damage
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RE: 230 V electrical problems
jraef - It is single phase though.
rbulsara - I really dont know its power, but its alot of equipment that has failed as well as hang ups, new equipment. The maintaince people running the building are trying to stay its that the equipment is not maintained, but two of the $40k freezers are from different models and less than a month old. I dunno. Could be probability.
Ill scope it tomorrow. I waited today to talk with the maintaince/engineeering people before I did anything. Not sure what ill find.
RE: 230 V electrical problems
RE: 230 V electrical problems
Rafiq Bulsara
http://www.srengineersct.com
RE: 230 V electrical problems
Measure the voltage at the units.
Is your system actually 230 or 208 volts?
As others have pointed out, the best approach is to keep it simple and check the most obvious to start with.
Alan
RE: 230 V electrical problems
Does the utility use an old type electromechanical Watt-Hour Meter or one of the newer electronic meters. Some electronic meters may be set to log voltage, current and other parameters every 15 minutes. Some utilities are kind enough to download the logs and e-mail them in Excell format. I have used that information to solve a couple of problems.
Bill
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"Why not the best?"
Jimmy Carter
RE: 230 V electrical problems
Hard to imagine month old units having cleaning or maintenance problems, but I guess it's possible to have a bad dust problem or maybe more likely a poor choice of location for air flow, ambient temperatures etc.
Refrigeration units are usually very well protected against electrical supply problems. I think it's more likely the usage they are seeing (cooling load etc) might be too much. Pulling a -40 degree freezer down to shutoff temperature takes a lot of compressor work, and frequent door opening, poor gaskets on the doors etc make a huge difference in the workload for the compressors.
RE: 230 V electrical problems
they are 208V
one of hte maintaince people had a monitor attached in the building that logs data. They did record what they call a small fluctiation the day we had the last problem. They also attached another closer to the freezers. i guess we are manually checking it for now.
RE: 230 V electrical problems
RE: 230 V electrical problems
Alan
RE: 230 V electrical problems
If you are using 208 volt rated compressors on a 230 Volt system get ready for a lot of burnouts.
208 Volts is a very common commercial voltage, and there are a lot of 208 Volt rated compressors out there. If a supplier has been sloppy and supplied 208 volt equipment for a 230 (nominal 240 Volt) system you may have a claim. If the mistake was in your organization be discrete.
LPS to racobb for the heads up on this issue.
Bill
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"Why not the best?"
Jimmy Carter
RE: 230 V electrical problems
Tounge in cheek! (TIC)
Thanks
Alan
RE: 230 V electrical problems
RE: 230 V electrical problems
Alan
RE: 230 V electrical problems
The next would be bad cooling of the returned gas. A minus 80C freezer is absolutely going to be a cascade system. It will likely have three compressor stages with different refrigerants in each loop. Everything has to be dead nuts on or failure is assured by some stage not getting the cooling it needs from the next stage above.
You/they need to have a crack refrigeration guy who understands the vulgarities of a cascade system check everything.
Keith Cress
kcress - http://www.flaminsystems.com
RE: 230 V electrical problems
Our setup was two stage but I agree with itsmoked about needing experienced help on-site.
I am surprised that the compressors are not belt driven.
A malfunction in one stage may cause an overload and eventual burnout in another stage.
Bill
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"Why not the best?"
Jimmy Carter
RE: 230 V electrical problems
it looks like the freezer is 208 and plugged into 208. It can run on either 230 or 208 though.
Im guessing our maintaince people are going to be montioring it, as from the last post. They installed a power monitors. The also had a general power montior that recorded some power flucations that day we had problems.
if anyones instrested, this is what these types of freezers look like
htt
I really think im alll set with this at this point unless someone can recommed some type of UPC for 208
RE: 230 V electrical problems
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: 230 V electrical problems
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: 230 V electrical problems
The machine's name plate will say 208-230 but that's
If you actually look at the plate on the compressor it will say something like 200V/50Hz 230V/60Hz.
The only way to make these things reliable is to use boost transformers to get the voltage up to 230V.
Keep in mind that the single phase units have a lot more failures than the three phase units because of all the starting junk needed, and the very high starting duty cycles these deeep freezes need.
Keith Cress
kcress - http://www.flaminsystems.com
RE: 230 V electrical problems
A quick check of Grainger.com shows some farm duty motors rated for 200-230 Volts 60 Hz and some at 208-230 Volts. I assume that these are basically 230 Volt motors that are slightly oversized so as to be able to deliver full HP at the reduced voltage.
I have also been seeing 200-230 Volt rated hermetic compressors in the field.
We've known each other long enough that you know that I know the difference between 50Hz and 60Hz. Grin
Yours
Bill
Bill
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"Why not the best?"
Jimmy Carter