snmp phase load status questions.

[Anonymous user]

my question is in regards to data I will be using for graphing. What is the phase load used for? I noticed that the bank load is in amps. I assume each of the 3 banks has a 20A maximum based on the 20A symbol located on the breaker for each bank. This should then help me see if one bank is never going over 10 I shuold be able to add at least 5 more Amps safely. I did see however that even though one of the banks load is the higest that doesnt alawys mean the phase load is the highest. What is that data used to tell so I can know how to monitor it better? Thank you for all your help.

[BillP · Accepted solution]

Phase load is provided and used because each of the banks typically reference two of the three phases from your incoming 3 phase power. It is important to load balance the phases and ultimately the banks. So, if you're monitoring the banks at least, and balance those accordingly (using all three banks evenly), your phases will likely be balanced fairly evenly for the most part. The key is not overloading your banks which are powered by your phases.

I am not a 3 phase power expert personally but some people may worry about the phase loads only I guess, maybe for concerns upstream from the Rack PDU relating to power...? The only thing I could think of is if you somehow only load two out of the three banks and somehow overload one particular phase if the two banks you pick reference one of the same phases..? I asked someone on our 3 phase power support team and they couldn't provide me a reason to focus on just phase load only but in reality, because of how the banks are organized, your phase loads should be relatively balanced too.

On page 2 here, http://www.apcmedia.com/salestools/VBUH-86MPWY/VBUH-86MPWY_R2_EN.pdf, you'll see the phase references.

Let me know if further questions.