mdillonelectrician
Member
- Location
- cape cod massachusetts
TRYING TO FILL OUT LABEL REQUIREMENTS, NOT SURE OF FORMULA FOR FIGURING AC OPERATING CURRENT AND OPERATING VOLTAGE.
HOW DO I CALCULATE AC OPERATING CURRENT/VOLTAGE FOR PV?
- Thread starter mdillonelectrician
- Start date
- Status
- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
I leave the answer to someone else, for I do not know how to do it either. But let me request that you turn off the ALL CAPS feature. It makes the post harder to read, and is considered impolite (as though you were SHOUTING at us). Welcome to the forum.
Label for what, precisely?
Providing as many details as possible will help.
mdillonelectrician
Member
- Location
- cape cod massachusetts
Sorry about the caps.Just thought it looked cleaner. I am putting a label on a 200 A main breaker panel that is backfed by 5 kw solar system.the label reads : "WARNING EQUIPMENT IS ENERGIZED BY TWO SOURCES PV SYSTEM AND UTILITY GRID. AC OPERATING VOLTAGE_________ AC OPERATING CURRENT________."seems silly but i just dont want to do it wrong.
K8MHZ
Senior Member
- Occupation
- Electrician
What does it say on the inverter?
mdillonelectrician
Member
- Location
- cape cod massachusetts
it says 240 volt 22.1 amps on the inverter...so the answer is that? I guess i should have looked a little closer hahaha thanks!
jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
Sounds like you have a DC system (not a microinverter system).
On the AC side you should have the operating voltage and the maximum current, as you have already figured out.
The DC side should also be labeled, usually at the disconnect.
This label should have:
On the AC side you should have the operating voltage and the maximum current, as you have already figured out.
The DC side should also be labeled, usually at the disconnect.
This label should have:
- Maximum voltage: This is the open circuit voltage (Voc) marked on each panel, multiplied by the number of panels in each string on the system, multiplied by a low temperature factor you get from table 690.7. Read 690.7 (A). In coastal California we use 1.15 for the temperature correction.
- Operating voltage: This is the max power voltage (vmp) marked on each panel, multiplied by the number of panels in each string.
- Operating current. This is the maximum power current (Imp) marked on each panel, multiplied by the number of paralleled strings.
- Maximum current: This is the short circuit current (Isc) marked on each panel, multiplied by the number of paralleled strings, multiplied by 1.25, as described in 690.8(A).
Basically what others said: look at inverter label. (make sure you aren't readind DC amps!)
Otherwise: Just divide Watt rating of inverter by rated voltage. In your case 5000W / 240 VAC = 20.83 A
In your case, UNUSUALLY, the inv. gives you a higher rating (!) Go with that.
_ The 125% cont. use factor is for your calc.s in sizing wire.
- Remember the wording "do not relocate" must be on label also -- in most cases , i forget exact code, but you can look it up! (eg backfed breaker opposite feed in load panel).
- You cannot use a 25A brkr. 30A needed.
Otherwise: Just divide Watt rating of inverter by rated voltage. In your case 5000W / 240 VAC = 20.83 A
In your case, UNUSUALLY, the inv. gives you a higher rating (!) Go with that.
_ The 125% cont. use factor is for your calc.s in sizing wire.
- Remember the wording "do not relocate" must be on label also -- in most cases , i forget exact code, but you can look it up! (eg backfed breaker opposite feed in load panel).
- You cannot use a 25A brkr. 30A needed.
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