Mbf1968
New member
- Location
- Portola valley, ca, usa
Hi, new member here and hoping someone can help me out. I am going to self install a pv array on my roof and need to provide the following info to town in order to get the permit.
rated max power point current in ADC
rated max power point voltace in VDC
short circuit current in ADC
Maximum system voltage in VDC
I'm using fourty suniva 280 watt panels, on micro inverters (enecsys 250W). There will be 4 arrays in total: array 1 = 11 panels, array 2 = 12 panels, array 3 = 13 panels, & array 4 = 4 panels. The arrays will feed into a sub panel with 30 amp breakers. The sub panel will use 8 gauge romex to run to the main panel with 40 amp breakers.
I saw that the formulas are as follows:
1. Maximum power point current (Imp) is the published Imp for a module X the number of strings. No multiplier.
2. Maximum power point voltage (Vmp) is the published Vmp for a module X the number modules in a string. All strings will be the same length.
3. Maximum system voltage is the published open circuit voltage (Voc) of a module, corrected for the lowest expected temperature (typically the record low for the location) X the number modules in a string. Code says use the published coefficients if they are available, otherwise the table. I haven't seen a module in several years that did not have a published coefficient.
4. Short circuit current (Isc) is the published Isc for a module X the number of strings. No multiplier.
5. Maximum rated output current for the charge controller or inverter is on the data sheet. No multiplier.
What I am unsure of is what values to use in order to get the correct answers. My town will not help me on this, so if I don't go with the correct answers I just get sent back without the permit. Any help is appreciated. Best,
Mike
rated max power point current in ADC
rated max power point voltace in VDC
short circuit current in ADC
Maximum system voltage in VDC
I'm using fourty suniva 280 watt panels, on micro inverters (enecsys 250W). There will be 4 arrays in total: array 1 = 11 panels, array 2 = 12 panels, array 3 = 13 panels, & array 4 = 4 panels. The arrays will feed into a sub panel with 30 amp breakers. The sub panel will use 8 gauge romex to run to the main panel with 40 amp breakers.
I saw that the formulas are as follows:
1. Maximum power point current (Imp) is the published Imp for a module X the number of strings. No multiplier.
2. Maximum power point voltage (Vmp) is the published Vmp for a module X the number modules in a string. All strings will be the same length.
3. Maximum system voltage is the published open circuit voltage (Voc) of a module, corrected for the lowest expected temperature (typically the record low for the location) X the number modules in a string. Code says use the published coefficients if they are available, otherwise the table. I haven't seen a module in several years that did not have a published coefficient.
4. Short circuit current (Isc) is the published Isc for a module X the number of strings. No multiplier.
5. Maximum rated output current for the charge controller or inverter is on the data sheet. No multiplier.
What I am unsure of is what values to use in order to get the correct answers. My town will not help me on this, so if I don't go with the correct answers I just get sent back without the permit. Any help is appreciated. Best,
Mike