Page 1 of 13
SCOPE: Use this plan ONLY for utility-interactive central/string inverter systems not exceeding a system AC inverter output
rating of 10kW on the roof of a one- or two-family dwelling or accessory structure. The photovoltaic system must
interconnect to the load side of a single-phase AC service panel of nominal 120/240Vac with a bus bar rating of 225A or
less. This plan is not intended for bipolar systems, hybrid systems or systems that utilize storage batteries, charge
controllers, trackers, more than two inverters or more than one DC combiner (noninverter-integrated) per inverter.
Systems must be in compliance with current California Building Standards Codes and local amendments of the authority
having jurisdiction (AHJ). Other Articles of the California Electrical Code (CEC) shall apply as specified in 690.3.
MANUFACTURER’S SPECIFICATION SHEETS MUST BE PROVIDED for proposed inverter, modules, combiner/junction boxes
and racking systems. Installation instructions for bonding and grounding equipment shall be provided, and local AHJs may
require additional details. Listed and labeled equipment shall be installed and used in accordance with any instructions
included in the listing or labeling (CEC 110.3). Equipment intended for use with PV system shall be identified and listed for
the application (CEC 690.4[D]).
Job Address: ______________________________________________ Permit #: ________________________
Contractor/ Engineer Name: _________________________________ License # and Class: ________________
Signature: _______________________________ Date: ___________ Phone Number: ___________________
Total # of Inverters installed: ____________ (If more than one inverter, complete and attach the “Supplemental
Calculation Sheets” and the “Load Center Calculations” if a new load center is to be used.)
Inverter 1 AC Output Power Rating: _______________________ Watts
Inverter 2 AC Output Power Rating (if applicable): ____________ Watts
Combined Inverter Output Power Rating: ___________________ ≤ 10,000 Watts
Location Ambient Temperatures (Check box next to which lowest expected temperature is used):
1)
Lowest expected ambient temperature for the location (T
L
) = Between -1 to -5 °C
Lowest expected ambient temperature for the location (T
L
) = Between -6 to -10 °C
Average ambient high temperature (T
H
) = 47 °C
Note: For a lower T
L
or a higher T
H
, use the Comprehensive Standard Plan
DC Information:
Module Manufacturer: _________________________________ Model: ___________________________
2) Module V
oc
(from module nameplate): _____Volts
3) Module I
sc
(from module nameplate): _______Amps
4) Module DC output power under standard test conditions (STC) = ________ Watts (STC)
Solar PV Standard Plan Simplified
Central/String Inverter Systems for
One- and Two-Family Dwellings
click to sign
signature
click to edit
Page 2 of 13
5) DC Module Layout
Identify each source circuit (string)
for inverter 1 shown on the roof
plan with a Tag (e.g., A, B ,C…)
Number of modules per
source circuit for inverter 1
Identify, by tag, which source circuits on the roof are to
be paralleled (if none, put N/A)
Combiner 1:
Combiner 2:
6) Are DC/DC Converters used? Yes No If No, skip to STEP 7. If Yes, enter info below.
DC/DC Converter Max DC Input Voltage: ______Volts
Max DC Output Voltage: ____________________Volts
DC/DC Converter Max DC Input Power: __ _____ Watts
7) Max. System DC Voltage Use A1 or A2 for systems without DC/DC converters, and B1 or B2 with DC/DC converters.
A1. Module V
OC
(STEP 2) = __________ x # in series (STEP 5) ________x 1.12 (If -1T
L
-5°C, STEP 1) = _________ V
A2. Module V
OC
(STEP 2) = __________ x # in series (STEP 5) ________x 1.14 (If -6T
L
-10°C, STEP 1) = ________ V
Table 1. Maximum Number of PV Modules in Series Based on Module Rated VOC for 600 Vdc Rated Equipment (CEC 690.7)
Max. Rated Module
VOC (*1.12)
(Volts)
29.76
31.51
33.48
35.71
38.27
41.21
44.64
48.70
53.57
59.52
66.96
76.53
89.29
Max. Rated Module
VOC (*1.14)
(Volts)
29.24
30.96
32.89
35.09
37.59
40.49
43.86
47.85
52.63
58.48
65.79
75.19
87.72
Max # of Modules for
600 Vdc
18
17
16
15
14
13
12
11
10
9
8
7
6
Use for DC/DC converters. The value calculated below must be less than DC/DC converter max DC input voltage (STEP #6).
B1. Module V
OC
(STEP 2)______ x # of modules per converter (STEP 6)____x 1.12 (If -1T
L
-5°C, STEP 1) = _____ V
B2. Module V
OC
(STEP 2)______ x # of modules per converter (STEP 6)____x 1.14 (If -6T
L
-10°C, STEP 1) = _____ V
Table 2. Largest Module VOC for Single-Module DC/DC Converter Configurations (With 80V AFCI Cap) (CEC 690.7 and 690.11)
Max. Rated
Module VOC
(*1.12) (Volts)
30.4
33.0
35.7
38.4
41.1
43.8
46.4
49.1
51.8
54.5
57.1
59.8
62.5
65.2
67.9
70.5
Max. Rated
Module VOC
(*1.14) (Volts)
29.8
32.5
35.1
37.7
40.4
43.0
45.6
48.2
50.9
53.5
56.1
58.8
61.4
64.0
66.7
69.3
DC/DC Converter
Max DC Input
(STEP #6) (Volts)
34
37
40
43
46
49
52
55
58
61
64
67
70
73
76
79
8) Maximum System DC Voltage from DC/DC Converters to Inverter Only required if Yes in STEP 6
Maximum System DC Voltage = ___________________ Volts
9) Maximum Source Circuit Current
Is Module I
SC
below 9.6 Amps (STEP 3)? Yes No (if No, use Comprehensive Standard Plan)
Page 3 of 13
10) Sizing Source Circuit Conductors
Source Circuit Conductor Size = Min. #10 AWG copper conductor, 90°C wet (USE-2, PV Wire, XHHW-2,
THWN-2, RHW-2)
For up to 8 conductors in roof-mounted conduit exposed to sunlight at least ½” from the roof covering (CEC 310)
Note: For over 8 conductors in the conduit or mounting height of lower than ½“from the roof, use Comprehensive Plan.
11) Are PV source circuits combined prior to the inverter? )? Yes No
If No, use Single Line Diagram 1 with Single Line Diagram 3 and proceed to STEP 13.
If Yes, use Single Line Diagram 2 with Single Line Diagram 4 and proceed to STEP 12.
Is source circuit OCPD required? Yes No
Source circuit OCPD size (if needed): 15 Amps
12) Sizing PV Output Circuit Conductors If a combiner box will NOT be used from [STEP 11],
Output Circuit Conductor Size = Min. #6 AWG copper conductor
13) Inverter DC Disconnect
Does the inverter have an integrated DC disconnect? Yes No If yes, proceed to STEP 14.
If no, the external DC disconnect to be installed is rated for ______ Amps (DC) and _______Volts (DC)
14) Inverter information
Manufacturer: _____________________________________ Model: __________________________________
Max. Continuous AC Output Current Rating: ______Amps
Integrated DC Arc-Fault Circuit Protection? Yes No (If No is selected, Comprehensive Standard Plan)
Grounded or Ungrounded System: Grounded Ungrounded
AC Information:
15) Sizing Inverter Output Circuit Conductors and OCPD
Inverter Output OCPD rating = ______ Amps (Table 3)
Inverter Output Circuit Conductor Size = ______ AWG (Table 3)
Table 3. Minimum Inverter Output OCPD and Circuit Conductor Size
Inverter Continuous Output Current Rating (Amps) (STEP#14)
12
16
20
24
28
32
36
40
48
Minimum OCPD Size (Amps)
15
20
25
30
35
40
45
50
60
Minimum Conductor Size (AWG, 75°C, Copper)
14
12
10
10
8
8
6
6
6
Page 4 of 13
16) Point of Connection to Utility
Only load side connections are permitted with this plan. Otherwise, use Comprehensive Standard Plan.
Is the PV OCPD positioned at the opposite end from input feeder location or main OCPD location? Yes No
If Yes, circle the Max Combined PV System OCPD(s) at 120% value as determined from STEP 15 (or STEP S20),
bus bar Rating, and Main OCPD as shown in Table 4.
If No, circle the Max Combined PV System OCPD(s) at 100% value as determined from STEP 15 (or STEP S20), bus
bar Rating, and Main OCPD as shown in Table 4.
Per 705.12(D)(2): [Inverter output OCPD size [STEP #15 or S20] + Main OCPD Size]≤[bus size × (100% or 120%)]
Table 4. Maximum Combined Supply OCPDs Based on Bus Bar Rating (Amps) per CEC 705.12(D)(2)
Bus bar Rating
100
125
125
200
200
200
225
225
225
Main OCPD
100
100
125
150
175
200
175
200
225
Max Combined PV System OCPD(s)
at 120% of bus bar Rating
20
50
25
60*
60*
40
60*
60*
45
Max Combined PV System OCPD(s)
at 100% of bus bar Rating
0
25
0
50
25
0
50
25
0
*This value has been lowered to 60 A from the calculated value to reflect 10kW AC size maximum.
Reduction of the main breaker is not permitted with this plan. Otherwise, use Comprehensive Standard Plan.
17 & 18 & 19) Labels and Grounding and Bonding
This content is covered by the labels on Page 4 and the Single Line Diagram(s). For background information,
refer to the Comprehensive Standard Plan.
Page 5 of 13
Solar PV Standard Plan Simplified
Central/String Inverter Systems for One- and Two-Family Dwellings
Markings
CEC Articles 690 and 705 and CRC Section R331 require the following labels or markings be installed at these
components of the photovoltaic system:
WARNING
ELECTRIC SHOCK HAZARD. THE DC
CONDUCTORS OF THIS PHOTOVOLTAIC
SYSTEM ARE UNGROUNDED AND MAY
BE ENERGIZED
WARNING
INVERTER OUTPUT CONNECTION;
DO NOT RELOCATE THIS
OVERCURRENT DEVICE
CRC R331.2 and CFC 605.11.1
[Marked on junction/combiner boxes
and conduit every 10’]
WARNING: PHOTOVOLTAIC
POWER SOURCE
J/Box
PV SYSTEM AC DISCONNECT
RATED AC OUTPUT CURRENT - ____AMPS
AC NORMAL OPERATING VOLTAGE ___VOLTS
M
A
C
INVERTER
D
C
WARNING
DUAL POWER SOURCES
SECOND SOURCE IS PHOTOVOLTAIC SYSTEM
RATED AC OUTPUT CURRENT- ____AMPS AC
NORMAL OPERATING VOLTAGE ___VOLTS
WARNING
ELECTRIC SHOCK HAZARD
DO NOT TOUCH TERMINALS
TERMINALS ON BOTH LINE AND LOAD
SIDES MAY BE ENERGIZED IN THE
OPEN POSITION
PV SYSTEM DC DISCONNECT
RATED MAX POWER-POINT CURRENT- ___ADC
RATED MAX POWER-POINT VOLTAGE- ___VDC
SHORT CIRCUIT CURRENT- ___ADC
MAXIMUM SYSTEM VOLTAGE- ___VDC
CEC 705.12(D)(7)
[Not required if panelboard is rated not
less than sum of ampere ratings of all
overcurrent devices supplying it]
CEC 690.35(F)
[Only required for ungrounded systems]
CEC 690.54
CEC 690.53
CEC 690.17
CEC 690.54 & CEC 705.12(D)(4)
WARNING
ELECTRIC SHOCK HAZARD
IF A GROUND FAULT IS INDICATED,
NORMALLY GROUNDED CONDUCTORS
MAY BE UNGROUNDED AND ENERGIZED
CEC 690.5(C)
[Normally already present on listed inverters]
Code Abbreviations:
California Electrical Code (CEC)
California Residential Code (CRC)
California Fire Code (CFC)
Informational note: ANSI Z535.4 provides guidelines for the design of safety signs and labels for application to products. A phenolic
plaque with contrasting colors between the text and background would meet the intent of the code for permanency. No type size is
specified, but 20 point (3/8”) should be considered the minimum.
CEC 705.12 requires a permanent plaque or directory denoting all electric power sources on or in the premises.
Page 6 of 13
Solar PV Standard Plan Simplified
Central/String Inverter System for One- and Two-Family Dwellings
TAG
1
2
3
4
5
6
7
8
9
10
AC
DC
G
MAIN SERVICE PANEL
6
7
5
CB 1
CB 1
CB 2
CB 2
3
1
10
MAIN
OCPD
G
8
PV OCPD
M
4
___ MODULES
___ MODULES
___ MODULES
___ MODULES
A
D
B
C
TAG DESCRIPTION AND CONDUCTOR TYPE
CONDUCTOR
SIZE
CONDUCTORS
CONDUIT/CABLE
TYPE
CONDUIT SIZE
A
USE-2 OR PV-WIRE
B
C
D
EGC/GEC:
CONDUCTOR/CONDUIT SCHEDULE
M
9
CHECK A BOX FOR WHETHER SYSTEM IS GROUNDED OR UNGROUNDED: GROUNDED (INCLUDE GEC)
UNGROUNDED
ENTER “N/A” WHERE SUITABLE FOR
WHEN NOT USING CONDUIT OR CABLE
AS PERMITTED BY CODE
2
IF DC/DC CONVERTERS ARE USED, CHECK THE BOX BELOW THE CORRESPONDING CONFIGURATION
PARALLEL DC/DC CONVERTERS ON ONE
SOURCE CIRCUIT (FIXED UNIT VOLTAGE
DC/DC CONVERTERS)
DC/DC CONVERTERS ARE ALL RUN
IN SERIES (FIXED SOURCE CIRCUIT
VOLTAGE DC/DC CONVERTERS)
+
+
-
-
+
+
-
-
INVERTER
DC/DC
CONVERTERS
DC/DC
CONVERTERS
FOR UNGROUNDED SYSTEMS:
- DC OCPD MUST DISCONNECT BOTH CONDUCTORS OF EACH SOURCE CIRCUIT
- UNGROUNDED CONDUCTORS MUST BE IDENTIFIED PER 210.5(C). WHITE-FINISHED CONDUCTORS ARE NOT PERMITTED.
+
-
+
-
INVERTER
SINGLE-LINE DIAGRAM #1 NO STRINGS COMBINED PRIOR TO INVERTER
*
N/A
N/A
N/A
N/A
EMT
3/4"
INSULATED EGC:
BARE COPPER EQ. GRD. COND. (EGC)
EMT
3/4"
N/A
N/A
EGC/GEC:
EMT
3/4"
NUM/COLOR
NOTE: 1
Consult with your local AHJ and / or Utility
*
THE MAIN SERVICE PANEL, PRODUCTION METER, AND AC DISCONNECT MUST BE WITHIN 8-FEET FROM
OUTSIDE EDGE TO OUTSIED EDGE OF THE EQUIPMENT, THERE MUST BE A MINIMUM 10-INCH SPACING
SIDE TO SIDE BETWEEN THE EQUIPMENT. (PER AZUSA LIGHT & WATER.)
SEE NOTE 1 FOR SPACING REQUIRMENTS
DESCRIPTION
SOLAR PV MODULE / STRING
DC/DC CONVERTERS INSTALLED? YES NO (IF YES, STEPS 6 & 8 REQUIRED)
SOURCE CIRCUIT JUNCTION BOX INSTALLED? YES NO
SEPARATE DC DISCINNECT INSTALLED? YES NO
INTERNAL INVERTER DC DICONNECT: YES NO
CENTRAL INVERTER
LOAD CENTER INSTALLED? YES NO
SEPARATE AC DISCONNECT INSTALLED. REQUIRED
PV PRODUCTION METER INSTALLED. REQUIRED
CONNECT TO INVERTER #2 (USE LINE DIAGRAM2)
#6
Page 7 of 13
Solar PV Standard Plan Simplified
Central/String Inverter System for One- and Two-Family Dwellings
TAG
1
2
3
4
5
6
7
8
9
10
11
AC
DC
G
MAIN SERVICE PANEL
7
8
6
CB 1
CB 1
CB 2
CB 2
3
1
11
MAIN
OCPD
G
9
PV OCPD
M
5
___ MODULES
___ MODULES
___ MODULES
___ MODULES
E
D
TAG
DESCRIPTION AND
CONDUCTOR TYPE
CONDUCTOR
SIZE
NUMBER OF
CONDUCTORS
CONDUIT/CABLE
TYPE
CONDUIT SIZE
A1
USE-2 OR PV-WIRE
EGC/GEC:
B1
EGC/GEC:
C
EGC/GEC:
D
EGC/GEC:
E
EGC/GEC:
COMBINER CONDUCTOR/CONDUIT SCHEDULE
M
10
CHECK A BOX FOR WHETHER SYSTEM IS GROUNDED OR UNGROUNDED: GROUNDED (INCLUDE GEC)
UNGROUNDED
ENTER “N/A” WHERE SUITABLE FOR WHEN NOT USING CONDUIT OR CABLE AS PERMITTED BY CODE
2
IF DC/DC CONVERTERS ARE USED, THEY
ARE RUN IN SERIES (FIXED SOURCE
CIRCUIT VOLTAGE DC/DC CONVERTERS)
+
+
-
-
INVERTER
DC/DC
CONVERTERS
FOR UNGROUNDED SYSTEMS:
- DC OCPD MUST DISCONNECT BOTH CONDUCTORS OF EACH SOURCE CIRCUIT
- UNGROUNDED CONDUCTORS MUST BE IDENTIFIED PER 210.5(C). WHITE-FINISHED CONDUCTORS ARE NOT PERMITTED.
+
-
4
B1
C
A1
SINGLE-LINE DIAGRAM #2 COMBINING STRINGS PRIOR TO INVERTER
___ MODULES
___ MODULES
B2
A2
TAG
DESCRIPTION AND
CONDUCTOR TYPE
CONDUCTOR
SIZE
NUMBER OF
CONDUCTORS
CONDUIT/CABLE
TYPE
CONDUIT SIZE
A2 USE-2 OR PV-WIRE
EGC/GEC:
B2
EGC/GEC:
NON-COMBINED STRINGS CONDUCTOR/CONDUIT SCHEDULE (IF APPLICABLE)
* Consult with your local AHJ and /or Utility
*
DESCRIPTION
SOLAR PV MODULE / STRING
DC/DC CONVERTERS INSTALLED? YES NO (IF YES, STEPS 6 & 8 REQUIRED)
SOURCE CIRCUIT JUNCTION BOX INSTALLED?: YES NO
COMBINER BOX (STEPS 11 & 12 REQUIRED)
SEPARATE DC DISCONNECT INSTALLED?: YES NO
INTERNAL INVERTER DC DISCONNECT: YES NO
CENTRAL INVERTER
LOAD CENTER INSTALLED?: YES NO
SEPARATE AC DISCONNECT INSTALLED?: REQUIRED
PV PRODUCTION METER INSTALLED. REQUIRED
CONNECT TO INVERTER #2 (USE LINE DIAGRAM 4)
SEE NOTE 1 FOR SPACING REQUIRMENTS
NOTE: 1
THE MAIN SERVICE PANEL, PRODUCTION METER, AND AC DISCONNECT MUST BE WITHIN 8-FEET FROM
OUTSIDE EDGE TO OUTSIDE EDGE OF THE EQUIPMENT, THERE MUST BE A MINIMUM 10-INCH SPACING
SIDE TO SIDE BETWEEN THE EQUIPMENT. (PER AZUSA LIGHT & WATER.)
#6
#6
Page 8 of 13
Solar PV Standard Plan Simplified
Central/String Inverter Systems for One- and Two-Family Dwellings
Supplemental Calculation Sheets for Inverter #2
(Only include if second inverter is used)
DC Information:
Module Manufacturer: ________________________________ Model: ________________________________
S2) Module V
oc
(from module nameplate): _____Volts
S3) Module I
sc
(from module nameplate): _______Amps
S4) Module DC output power under standard test conditions (STC) = ________ Watts (STC)
S5) DC Module Layout
Identify each source circuit (string) for
inverter 1 shown on the roof plan with
a Tag (e.g., A, B, C …)
Number of modules
per source circuit for
inverter 1
Identify, by tag, which source circuits on the roof are to
be paralleled (if none, put N/A)
Combiner 1:
Combiner 2:
Total number of source circuits for inverter 1:
S6) Are DC/DC Converters used? Yes No If No, skip to STEP#S7. If Yes, enter info below.
DC/DC Converter Max DC Input Voltage: ________Volts
Max DC Output Voltage: _____________________Volts
DC/DC Converter Max DC Input Power: _________Watts
S7) Max. System DC Voltage Use A1 or A2 for systems without DC/DC converters, and B1 or B2 with DC/DC converters.
A1. Module V
OC
(STEP S2) = __________ x # in series (STEP S5)________x 1.12 (If -1T
L
-5°C, STEP S1) = ______ V
A2. Module V
OC
(STEP S2) = __________ x # in series (STEP S5)________x 1.14 (If -6T
L
-10°C, STEP S1) = ______ V
Table 1. Maximum Number of PV Modules in Series Based on Module Rated VOC for 600 Vdc Rated Equipment (CEC 690.7)
Max. Rated Module VOC (*1.12)
(Volts)
29.76
31.51
33.48
35.71
38.27
41.21
44.64
48.70
53.57
59.52
66.96
76.53
89.29
Max. Rated Module VOC (*1.14)
(Volts)
29.24
30.96
32.89
35.09
37.59
40.49
43.86
47.85
52.63
58.48
65.79
75.19
87.72
Max # of Modules for 600 Vdc
18
17
16
15
14
13
12
11
10
9
8
7
6
Use for DC/DC converters. The value calculated below must be less than DC/DC converter max DC input voltage (STEP #S6).
B1. Module V
OC
(STEP#S2) _____ x # of modules per converter (STEP S6) ____x 1.12 (If -1T
L
-5°C, STEP S1) = _____ V
B2. Module V
OC
(STEP#S2) _____ x # of modules per converter (STEP S6) ____x 1.14 (If -6T
L
-10°C, STEP S1) = ____ V
Page 9 of 13
Table 2. Largest Module VOC for Single-Module DC/DC Converter Configurations (With 80V AFCI Cap) (CEC 690.7 and 690.11)
Max. Rated Module VOC
(*1.12) (Volts)
30.4
33.0
35.7
38.4
41.1
43.8
46.4
49.1
51.8
54.5
57.1
59.8
62.5
65.2
67.9
70.5
Max. Rated Module VOC
(*1.14) (Volts)
29.8
32.5
35.1
37.7
40.4
43.0
45.6
48.2
50.9
53.5
56.1
58.8
61.4
64.0
66.7
69.3
DC/DC Converter Max DC
Input (STEP #6) (Volts)
34
37
40
43
46
49
52
55
58
61
64
67
70
73
76
79
S8) Maximum System DC Voltage from DC/DC Converters to Inverter Only required if Yes in STEP S6
Maximum System DC Voltage = _________________ Volts
S9) Maximum Source Circuit Current
Is Module I
SC
below 9.6 Amps (STEP S3)? Yes No (if No, use Comprehensive Standard Plan)
S10) Sizing Source Circuit Conductors:
Source Circuit Conductor Size = Min. #10 AWG copper conductor, 90°C wet (USE-2, PV Wire, XHHW-2, THWN-2,
RHW-2)
For up to 8 conductors in roof-mounted conduit exposed to sunlight at least ½” from the roof covering (CEC 310)
Note: For over 8 conductors in the conduit or mounting height of lower than ½“from the roof, use
Comprehensive Plan.
S11) Are PV source circuits combined prior to the inverter? Yes No
If No, use Single Line Diagram 1 with Single Line Diagram 3 and proceed to STEP S13.
If Yes, use Single Line Diagram 2 with Single Line Diagram 4 and proceed to STEP S12.
Is source circuit OCPD required? Yes No
Source circuit OCPD size (if needed): 15 Amps
S12) Sizing PV Output Circuit Conductors If a Combiner box will NOT be used from [STEP#S11],
Output Circuit Conductor Size = Min. #6 AWG copper conductor
S13) Inverter DC Disconnect
Does the inverter have an integrated DC disconnect? Yes No If yes, proceed to STEP S14.
If No, the external DC disconnect to be installed is rated for ______ Amps (DC) and _______Volts (DC)
S14) Inverter information:
Manufacturer: _________________________________ Model: __________________________________
Max. Continuous AC Output Current Rating: ______ Amps
Integrated DC Arc-Fault Circuit Protection? Yes No (If No is selected, Comprehensive Standard Plan)
Grounded or Ungrounded System: GROUNDED UNGROUNDED
Page 10 of 13
AC Information:
S15) Sizing Inverter Output Circuit Conductors and OCPD:
Inverter Output OCPD rating = ______ Amps (Table 3)
Inverter Output Circuit Conductor Size = ______ AWG (Table 3)
Table 3. Minimum Inverter Output OCPD and Circuit Conductor Size
Inverter Continuous Output Current Rating (Amps) (STEP 14)
12
16
20
24
28
32
36
40
48
Minimum OCPD Size (Amps)
15
20
25
30
35
40
45
50
60
Minimum Conductor Size (AWG, 75°C, Copper)
14
12
10
10
8
8
6
6
6
Load Center Calculations
(Omit if a load center will not be installed for PV OCPDs)
S20) Load Center Output:
Calculate the sum of the maximum AC outputs from each inverter.
Inverter #1 Max Continuous AC Output Current Rating[STEP S14] _______ × 1.25 = ________ Amps
Inverter #2 Max Continuous AC Output Current Rating[STEP S14] _______ × 1.25 = ________ Amps
Total inverter currents connected to load center (sum of above) = ________ Amps
Conductor Size: ________ AWG
Overcurrent Protection Device: ________ Amps
Load center bus bar rating: ________ Amps
The sum of the ampere ratings of overcurrent devices in circuits supplying power to a bus bar or conductor shall
not exceed 120 percent of the rating of the bus bar or conductor.
Page 11 of 13
Solar PV Standard Plan Simplified
Central/String Inverter System for One- and Two-Family Dwellings
DESCRIPTION
SOLAR PV MODULE / STRING
DC/DC CONVERTERS INSTALLED? YES NO (IF YES, STEPS 6 & 8 REQUIRED)
SOURCE CIRCUIT JUNCTION BOX INSTALLED? YES NO
*
TO LOAD CENTER ON LINE DIAGRAM 1
TAG
1
2
3
4
5
6
7
8
AC
DC
6
5
3
1
4
___ MODULES
___ MODULES
___ MODULES
___ MODULES
A
B
C
TAG DESCRIPTION AND CONDUCTOR TYPE
CONDUCTOR
SIZE
NUMBER OF
CONDUCTORS
CONDUIT/CABLE
TYPE
CONDUIT SIZE
A
USE-2 OR PV-WIRE
EGC/GEC:
B
EGC/GEC:
C
EGC/GEC:
CONDUCTOR/CONDUIT SCHEDULE
CHECK A BOX FOR WHETHER SYSTEM IS GROUNDED OR UNGROUNDED: GROUNDED (INCLUDE GEC)
UNGROUNDED
ENTER “N/A” WHERE SUITABLE FOR WHEN
NOT USING CONDUIT OR CABLE AS
PERMITTED BY CODE
2
IF DC/DC CONVERTERS ARE USED, CHECK THE BOX BELOW THE CORRESPONDING CONFIGURATION
PARALLEL DC/DC CONVERTERS ON ONE
SOURCE CIRCUIT (FIXED UNIT VOLTAGE
DC/DC CONVERTERS)
DC/DC CONVERTERS ARE ALL RUN
IN SERIES (FIXED SOURCE CIRCUIT
VOLTAGE DC/DC CONVERTERS)
+
+
-
-
+
+
-
-
INVERTER
DC/DC
CONVERTERS
DC/DC
CONVERTERS
FOR UNGROUNDED SYSTEMS:
- DC OCPD MUST DISCONNECT BOTH CONDUCTORS OF EACH SOURCE CIRCUIT
- UNGROUNDED CONDUCTORS MUST BE IDENTIFIED PER 210.5(C). WHITE-FINISHED CONDUCTORS ARE NOT PERMITTED.
+
-
+
-
INVERTER
7
8
SINGLE-LINE DIAGRAM #3 ADDITIONAL INVERTER FOR DIAGRAM #1
INVERTER # 2
* Consult with your local AHJ and /or Utility
#6
SEPARATE DC DISCONNECT INSTALLED? YES NO
INTERNAL INVERTER DC DISCONNECT INSTALLED? YES NO
CENTRAL INVERTER
SEPARATE AC DISCONNECT INSTALLED? REQUIRED
Page 12 of 13
Solar PV Standard Plan Simplified
Central/String Inverter System for One- and Two-Family Dwellings
TAG
1
2
3
4
5
6
7
8
9
AC
DC
7
6
3
1
5
___ MODULES
___ MODULES
___ MODULES
___ MODULES
D
TAG
DESCRIPTION AND
CONDUCTOR TYPE
CONDUCTOR
SIZE
NUMBER OF
CONDUCTORS
CONDUIT/CABLE
TYPE
CONDUIT SIZE
A1
USE-2 OR PV-WIRE
EGC/GEC:
B1
EGC/GEC:
C
EGC/GEC:
D
EGC/GEC:
COMBINER CONDUCTOR/CONDUIT SCHEDULE
CHECK A BOX FOR WHETHER SYSTEM IS GROUNDED OR UNGROUNDED: GROUNDED (INCLUDE GEC)
UNGROUNDED
ENTER “N/A” WHERE SUITABLE FOR WHEN NOT USING CONDUIT OR CABLE AS PERMITTED BY CODE
2
IF DC/DC CONVERTERS ARE USED, THEY
ARE RUN IN SERIES (FIXED SOURCE
CIRCUIT VOLTAGE DC/DC CONVERTERS)
+
+
-
-
INVERTER
DC/DC
CONVERTERS
FOR UNGROUNDED SYSTEMS:
- DC OCPD MUST DISCONNECT BOTH CONDUCTORS OF EACH SOURCE CIRCUIT
- UNGROUNDED CONDUCTORS MUST BE IDENTIFIED PER 210.5(C). WHITE-FINISHED CONDUCTORS ARE NOT PERMITTED.
+
-
4
B1
C
A1
8
9
SINGLE-LINE DIAGRAM #4 ADDITIONAL INVERTER FOR DIAGRAM #2
INVERTER # 2
TAG
DESCRIPTION AND
CONDUCTOR TYPE
CONDUCTOR
SIZE
NUMBER OF
CONDUCTORS
CONDUIT/CABLE
TYPE
CONDUIT SIZE
A2 USE-2 OR PV-WIRE
EGC/GEC:
B2
EGC/GEC:
NON-COMBINED STRINGS CONDUCTOR/CONDUIT SCHEDULE (IF APPLICABLE)
___ MODULES
___ MODULES
B2
A2
* Consult with your local AHJ and /or Utility
(IF YES, STEPS 6 & 8 REQUIRED)
NO
NO
NO
DESCRIPTION
SOLAR PV MODULE / STRING
DC/DC CONVERTERS INSTALLED? YES NO
SOURCE CIRCUIT JUNCTION BOX INSTALLED? YES
COMBINER BOX (STEPS 11 & 12 REQUIRED)
SEPARATE DC DISCONNECT INSTALLED? YES
INTERNAL INVERTER DC DISCONNECT: YES
CENTRAL INVERTER
*
SEPARATE AC DISCONNECT INSTALLED? REQUIRED
TO LOAD CENTER ON LINE DIAGRAM 3
#6
#6
Page 13 of 13
SOLAR PV STANDARD PLAN
Roof Layout Diagram for One- and Two-Family Dwellings
Items required: roof layout of all panels, modules, clear access
pathways and approximate locations of electrical disconnecting
means and roof access points.