pl check this laod calculations
- Thread starter murli8
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- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I don't think I want to open any attachments from someone I don't know. Try and paste them on another post.
There is a way to safely look at that attachment if you have an anti-virus program on your computer with up-to-date virus definition files. Right click on the link and choose the "save as..." option this will allow you to save the file on your computer w/o opening it. Then navigate to the saved file on your computer and right click on the file. There should be an option to scan the file with your anti-virus program. If the scan finds no virus in the file, you should be safe to open the file. I did so with murli's file and nothing bad happened 
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
eprice said:I did so with murli's file and nothing bad happened
Yeah wait until tonight--- the boogie man comes out and your computer is fried---LOL
I know I could do that but even updated virus can't catch everyone. It could be a brand new one that the op did himself. I am not saying that is the case but I prefer to not mess with it.
zbang
Senior Member
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- Roughly 5346 miles from Earls Court
I don't see why the OP didn't just post the text in the first place. It's not like everyone even has ms-word.
- Location
- Illinois
- Occupation
- retired electrician
Why do you think that is a 208 volt delta system? It appears to show line to netural loads in the table.
Don
Don
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
don_resqcapt19 said:
Here is the op's question
murli8 said:
kingpb
Senior Member
- Location
- SE USA as far as you can go
- Occupation
- Engineer, Registered
I opened it and my virus protection didn't pick up anything, not to say......
Anyway, my understanding is that the "single phase loads" are 208V, 2-pole.
As far as a delta 208V, it is certainly plausible from an engineering standpoint. Might be used in a situation where the user is very concerned with tripping due to a minor ground fault. in this case they could continue to operate, while the trained personnel track down the fault and clear it. Someone else will have to chime in on whether there is a Code issue by operating 208V ungrounded or not.
Anyway, my understanding is that the "single phase loads" are 208V, 2-pole.
As far as a delta 208V, it is certainly plausible from an engineering standpoint. Might be used in a situation where the user is very concerned with tripping due to a minor ground fault. in this case they could continue to operate, while the trained personnel track down the fault and clear it. Someone else will have to chime in on whether there is a Code issue by operating 208V ungrounded or not.
- Location
- Illinois
- Occupation
- retired electrician
King,
The tables in the document are somewhat confusing. I see that they list currents as L1-L2, L2-L3 and L1-L3, so the loads are on two poles.
Don
The tables in the document are somewhat confusing. I see that they list currents as L1-L2, L2-L3 and L1-L3, so the loads are on two poles.
That would depend on the supply system. If is can be grounded so there is a maximum of 150 volts or less to ground, then the code would require it to be a grounded system. 250.20(B)(1)
Don
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
As others have noted. Please post this as text, not as a word document.
-Jon
-Jon
load information posted
load information posted
UPS
Des ph V CB "L1-L2" L2-L3" L1-L3" VA
CB8 1 208 10 0.0 6.0 1210
CB9 1 208 10 6.0 1210
CB13 1 208 10 6.0 0.0 1210
CB15 1 208 10 0.0 6.0 0.0 1210
CB10 1 208 10 0.0 7.0 1400
Tot Ph Cur 6.0 12.0 13.0
(sum) 6240
125% 7800 va
((7800/208)/1.732) = 22 amps
Facilities
Des Ph Volt CB L1-L2" L2-L3" L1-L3"
CB5 3 208 40 11.0 11.0 11.0 3962.816
CB6 3 208 40 11.0 11.0 11.0 3962.816
CB7 3 208 40 12.0 12.0 12.0 4323.072
CB11 1 208 16 6.0 0.0 0.0 1250
CB12 1 208 16 0.0 6.0 0.0 1450
CB14 1 208 16 0.0 0.0 5.0 850
CB16 1 208 16 0.0 8.0 0.0 1700
CB17 3 208 16 7.0 7.0 7.0 2521.792
CB18 3 208 16 7.0 7.0 7.0 2521.792
CB19 3 208 10 7.0 7.0 7.0 2521.792
total 61.0 69.0 60.0 25064.08 (total va)
125% 31330.1 va
((31330/208)/1.732) = 87 amps
SUMMARY
FACILITY 32KVA = 87 AMPS
UPS 8KVA = 22 AMPS
load information posted
UPS
Des ph V CB "L1-L2" L2-L3" L1-L3" VA
CB8 1 208 10 0.0 6.0 1210
CB9 1 208 10 6.0 1210
CB13 1 208 10 6.0 0.0 1210
CB15 1 208 10 0.0 6.0 0.0 1210
CB10 1 208 10 0.0 7.0 1400
Tot Ph Cur 6.0 12.0 13.0
(sum) 6240
125% 7800 va
((7800/208)/1.732) = 22 amps
Facilities
Des Ph Volt CB L1-L2" L2-L3" L1-L3"
CB5 3 208 40 11.0 11.0 11.0 3962.816
CB6 3 208 40 11.0 11.0 11.0 3962.816
CB7 3 208 40 12.0 12.0 12.0 4323.072
CB11 1 208 16 6.0 0.0 0.0 1250
CB12 1 208 16 0.0 6.0 0.0 1450
CB14 1 208 16 0.0 0.0 5.0 850
CB16 1 208 16 0.0 8.0 0.0 1700
CB17 3 208 16 7.0 7.0 7.0 2521.792
CB18 3 208 16 7.0 7.0 7.0 2521.792
CB19 3 208 10 7.0 7.0 7.0 2521.792
total 61.0 69.0 60.0 25064.08 (total va)
125% 31330.1 va
((31330/208)/1.732) = 87 amps
SUMMARY
FACILITY 32KVA = 87 AMPS
UPS 8KVA = 22 AMPS
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
murli8,
There appear to be several internal inconsistencies that spreadsheet.
1) The UPS loads all have VA values less than suggested by the current for those loads.
2) CB11 and CB12 have different VA values for the same current
3) Total current is not summed correctly. Your single phase loads are only in single columns, even though they are connected line-line, and thus each load _2_ lines. This is correct if you are tabulating the individual line-line currents. But the three phase numbers that you give are the _line_ currents, at least as judged by the VA for each three phase load. You should use one approach or the other, but not mix both in the same calculation.
4) Your circuit breaker numbering scheme doesn't provide any information regarding which phase(s) a breaker may be connected to. This is your internal convention, so not necessarily an error, but something to think about. In most panels there is a definite pattern as to which phases a circuit breaker connects to.
-Jon
There appear to be several internal inconsistencies that spreadsheet.
1) The UPS loads all have VA values less than suggested by the current for those loads.
2) CB11 and CB12 have different VA values for the same current
3) Total current is not summed correctly. Your single phase loads are only in single columns, even though they are connected line-line, and thus each load _2_ lines. This is correct if you are tabulating the individual line-line currents. But the three phase numbers that you give are the _line_ currents, at least as judged by the VA for each three phase load. You should use one approach or the other, but not mix both in the same calculation.
4) Your circuit breaker numbering scheme doesn't provide any information regarding which phase(s) a breaker may be connected to. This is your internal convention, so not necessarily an error, but something to think about. In most panels there is a definite pattern as to which phases a circuit breaker connects to.
-Jon
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