８・５－ field inspection items

e8 /

PPA

Sol

ar P

V D

esig

n Im

plem

enta

tion

O&

M

1

Mar

shal

l Isl

ands

Mar

ch 3

1-A

pril

11, 2

008

８・５８・５－－ Field Inspection ItemsField Inspection Items

8.5.1 　 Visual inspection and verification test of structure and quantity

　　　　　（ 1 ） Photovoltaic module

　　　　　（ 2 ） Support structure for photovoltaic module

　　　　　（ 3 ） Power conditioner

　　　　　（ 4 ） Display system

　　　　　（ 5 ） Junction box, Interconnection switchboard, MCB

8.5.2 　 Equipment installation and wiring/connection inspection

　　　　　（ 1 ） Equipment installation inspection

　　　　　（ 2 ） Wiring/connection verification test

8.5.3 　 Insulation resistance test

　　　　　（ 1 ） Wiring between photovoltaic modules

　　　　　（ 2 ） Wiring between various equipment

8.5.4 　 Open-circuit voltage test/earth resistance test

　　　　　（ 1 ） Open-circuit voltage of photovoltaic module

　　　　　（ 2) Earth resistance when systems are interconnected

　　　　

e8 /

PPA

Sol

ar P

V D

esig

n Im

plem

enta

tion

O&

M

2

Mar

shal

l Isl

ands

Mar

ch 3

1-A

pril

11, 2

008

8.5.1 　－ Visual inspection and verification test of structure and quantity

（ 1 ） Photovoltaic module visual inspection and power output test

Item Inspection details Means of inspection Result

Appearance

・ Check if there is any damage, cracking or deformation in the photovoltaic module appearance.

Visual inspection

・ Confirm that photovoltaic modules are appropriately arranged.

Consistent with Tech. Spec.

drawings

Power output

・ Check against manufacturers’ shop inspection records on behalf of conducting field output tests.

e8 /

PPA

Sol

ar P

V D

esig

n Im

plem

enta

tion

O&

M

3

Mar

shal

l Isl

ands

Mar

ch 3

1-A

pril

11, 2

008

（ 2 ） Visual inspection of Support structure for photovoltaic module array


Appearance

There is no deformation or strain. Visual inspection

There is no peeling of galvanized steel welded to support structure.

Visual inspection

The support structure is appropriately arranged.

Consistent with Tech. Spec. drawings

Installation

There is no loosening in screws, bolts and fixtures.

Visual inspection

Bolt tightening is appropriately conducted. Visual inspection

Wiring

There is no loosening in the connections between photovoltaic modules.

No loosening is confirmed by touching

and visually.

Exposed cables behind the photovoltaic module are wired in order.

Visual inspection

Cables are supported by fixing devices. Visual inspection

Earth cables are connected to the array support structure.

Visual inspection


e8 /

PPA

Sol

ar P

V D

esig

n Im

plem

enta

tion

O&

M

4

Mar

shal

l Isl

ands

Mar

ch 3

1-A

pril

11, 2

008

（ 3 ） Power conditioner 　　　　


AppearanceThere is neither peeling of surface coating nor deformation.

Visual inspection

InstallationThere is no loosening in screws, bolts and fixtures.

Visual inspection

Wiring

P/N （ +/- ） are correctly connected at the power conditioner input.

Visual inspection, tester

R/S/T are correctly connected at the three-phase output.


Low voltage cable +/- are correctly connected at its input/output.


Earth cables are connected. Visual inspection

Cables are connected in order. Visual inspection

The panel internal is clean. Visual inspection

Visual inspection 　


e8 /

PPA

Sol

ar P

V D

esig

n Im

plem

enta

tion

O&

M

5

Mar

shal

l Isl

ands

Mar

ch 3

1-A

pril

11, 2

008

（ 3 ） Power conditioner

Item Inspection details Performance Result Remarks

Model/typeCheck the type of power conditioner against Tech. Spec.

Acceptable

Protective relay test (at shop)

Check against shop inspection records on behalf of field relay tests.

Check against shop inspection records.

Islanding phenomen

on detection

MCCB （ ELCB ） is turned off and operation is shutdown in an instance.

Acceptable

20 seconds standby

after power restoration

The power conditioner automatically starts 20 seconds after power restoration.

20

Restart on S.

Acceptable

The time to restoration shall be consistent with Tech. Spec.

Performance test

Performance test

Regarding output inspection/test of relays, check against manufacturers’ shop inspection records on behalf of conducting field inspection/test.


e8 /

PPA

Sol

ar P

V D

esig

n Im

plem

enta

tion

O&

M

6

Mar

shal

l Isl

ands

Mar

ch 3

1-A

pril

11, 2

008

（ 4 ） Display system



Visual inspection

Installation There is no loosening in screws, bolts and fixtures. Visual inspection

Nameplate There is no defect to or peeling of nameplate. Visual inspection

Wiring

AC200V control power cables are correctly wired. Visual inspection, tester

Low voltage cables are correctly wired and there is conduction.


Cables are wired in order. Visual inspection


Visual inspection

LED verification test 　　　Item Inspection details Means of inspection Result

Verification of quantity

The generated electricity is consistent with the total of the numerical values shown in the power conditioner LCD. Visual inspection

＊ Input signals from the secondary cable in the transducer inside the interconnection switchboard to verify the indicated values on the LED screen.

＊ Visually check the numerical values indicated by power conditioner panel LCD or data collection system monitor to verify there is no error in the generated electricity of photovoltaic module and inverter output.


e8 /

PPA

Sol

ar P

V D

esig

n Im

plem

enta

tion

O&

M

7

Mar

shal

l Isl

ands

Mar

ch 3

1-A

pril

11, 2

008

（ 5 ） Junction box, interconnection switchboard and MCB　　　　

Item Inspection detailsMeans of inspection

Result


Visual inspection

Installation There is no loosening in screws, bolts and fixtures.

Visual inspection

Wiring

P/N （ +/- ） are correctly connected at the junction box input.

Visual inspection,

tester

P/N （ +/- ） are correctly connected at the MCCB output.

Visual inspection,

tester

Earth cables are connected.Visual

inspection

Cables are wired in order.Visual

inspection

The panel internal is clean.Visual

inspection

Visual inspection of junction box-1


e8 /

PPA

Sol

ar P

V D

esig

n Im

plem

enta

tion

O&

M

8

Mar

shal

l Isl

ands

Mar

ch 3

1-A

pril

11, 2

008

（ 5 ） Junction box, interconnection switchboard and MCB 　


Result


Visual inspection


Wiring

U/V/W are correctly connected at the inverter input.Visual inspection,

tester

U/V/W are correctly connected at the main MCCB output.





U/V/W phase indicator shows the positive phase at the inverter input

Visual inspection, phase indicator

Visual inspection of interconnection switchboard


e8 /

PPA

Sol

ar P

V D

esig

n Im

plem

enta

tion

O&

M

9

Mar

shal

l Isl

ands

Mar

ch 3

1-A

pril

11, 2

008

(5) Junction box, interconnection switchboard and MCB　　　　


Result


Visual inspection


wiring

U/V/W are correctly connected at the main MCCB input.


U/V/W are correctly connected at the main MCCB output.





U/V/W phase indicator shows the positive phase at main MCCB output.

Visual inspection, phase indicator

Visual inspection of MCB 　


e8 /

PPA

Sol

ar P

V D

esig

n Im

plem

enta

tion

O&

M

10

Mar

shal

l Isl

ands

Mar

ch 3

1-A

pril

11, 2

008

8.5.2 　－ Equipment installation and wiring/connection inspection

（ 1 ） , （ 2 ） Insulation resistance measurement of cable between junction box and inverter panel

　　　　　　 Insulation resistance measurement of cable between inverter and interconnection witchboard

　　　　　　 Insulation resistance measurement of cables between interconnection switchboard, MCB and 　　　　　 existing transducers

　［ Test procedure ］

　　 Measure the insulation resistance of （ + ，－） polarities and （ R ， S,T ） phases of each cable to ensure that there is no insulation failure.

　　 Measure the insulation resistance between each cable and the ground (according to the rules for internal cables).

　［ Acceptance criteria ］

　　 Measured voltage ＞ 600V ： Acceptable if measurement using 1000V megger shows 0.4MΩ or igher .

　　 Measured voltage ＞ 300V ： Acceptable if measurement using 500V megger shows 0.4MΩ or higher

　　 Measured voltage ＞ 150V ： Acceptable if measurement using 500V megger shows 0.2MΩ or higher.

　　 Measured voltage ＞ 150V ：　 Acceptable if measurement using 500V megger shows 0.1MΩ or higher.

e8 /

PPA

Sol

ar P

V D

esig

n Im

plem

enta

tion

O&

M

11

Mar

shal

l Isl

ands

Mar

ch 3

1-A

pril

11, 2

008

8.5.2 　 -Equipment installation and wiring/connection inspection

Measurement of cable insulation resistance

Item Insulation resistance （ M　）

Cable type Result

Junction box-1～ Inverter-1

P （＋） 100MΩ or higher CV10sq-4CEarth cable 1C, spare cable 1CN （－） 100MΩ or higher


P （＋） 100MΩ or higher CV10sq-4CEarth cable 1C, spare cable IC

N （－） 100MΩ or higher


P （＋） 100MΩ or higher CV10sq-4CEarth cable 1C, spare cable IC

N （－） 100MΩ or higher

Inverter-1 ～ Interconnection switchboard

R （ red ） 100MΩ or higher

CV14sq-4CS （ black ） 100MΩ or higher

T （ blue ） 100MΩ or higher

N （ white ） 100MΩ or higher

Interconnection switchboard ～ MCB





MCB ～ Existing transducer-9





>600V

>600V

>600V

>300V

>300V

>300V

e8 /

PPA

Sol

ar P

V D

esig

n Im

plem

enta

tion

O&

M

12

Mar

shal

l Isl

ands

Mar

ch 3

1-A

pril

11, 2

008

8.5.3 　－ Equipment installation and wiring/connection inspection

（ 1 ）、（ 2 ）　 Insulation resistance measurement of cables between photovoltaic modules

　　　［ Test procedure ］　　　　 Measure the insulation resistance of （ + ，－） polarities and （ R, S, T) phases of each cable for

one string of 　　 photovoltaic module array to verify that there is no insulation failure.

　　　　 Measure the insulation resistance between each cable and the ground (*The insulation resistance of the 　 cable including the photovoltaic module will be measured).

　　　［ Acceptance criteria ］　　　　 Open-circuit voltage≧300V ： Acceptable if measurement using 1000V megger shows 0.4MΩ or

higher .

Measurement of cable insulation resistance

Module No.Insulation resistance

（ M 　） Cable used Result

Junction box-1

PV1-1 　　 + 65MΩ or higher Manufacturer’s standard type （ 4sq-5C ）1C earth cable, spare cable 2C

Acceptable

PV1-1 　　 - 100MΩ or higher Acceptable


Acceptable



Acceptable



Acceptable



Acceptable


e8 /

PPA

Sol

ar P

V D

esig

n Im

plem

enta

tion

O&

M

13

Mar

shal

l Isl

ands

Mar

ch 3

1-A

pril

11, 2

008

8.5.4 　－ Open-circuit voltage test/earth resistance test

（ 1 ） DC Open-circuit voltage of cables between photovoltaic modules

　　　 The crystalline photovoltaic power generation system consists of 270 panels of 167 W module.

　　　 Eighteen modules （ 167W ）　 in series ×fifteen modules in parallel constitute a photovoltaic power generation system.

　　　 The open-circuit voltage of one module is about 43.1V （ at the highest ） with an error of ±10%. 　　　 Accordingly, the nominal voltage of one module accounts for 43.1V×0.9 ～1.1 ＝ 38.79 ～ 47.41V.

　　　 The maximum open-circuit voltage of one circuit consisting of 18 modules will be:

　　　 38.8V×18 modules ＝ 698.22V （ lower limit ）

　　　 47.4V×18 modules ＝ 853.38V （ upper limit ）

　　［ Test procedure ］

　　　・ Measure the open-circuit voltage of one each string of photovoltaic module array to confirm the polarity of each circuit.

　　　・ Measure the open-circuit voltage of one each string of photovoltaic module array to check if the number of modules in series is correct or not.

　　　＜ If the measured voltage is out of the acceptance criteria, the modules in series might be incorrectly connected. ＞

e8 /

PPA

Sol

ar P

V D

esig

n Im

plem

enta

tion

O&

M

14

Mar

shal

l Isl

ands

Mar

ch 3

1-A

pril

11, 2

008


（ 1 ） DC Open-circuit voltage of cables between photovoltaic modules

　　［ Test conditions ］

　　　 Tests shall be conducted during daytime hours on a sunny day. （ Solar radiation shall be 0.1kW/m2 or higher. ）

　　　

　　［ Acceptance criteria ］

　　　 Measure the open-circuit voltage of one each string of module array to confirm that it meets the following criteria.

Measurement at junction box

Module train No.Junction box-1

Polarity （ + ， - ） Open-circuit voltage (Voc)Acceptance criteria

698V ～ 853V

Junction box-1

PV1-1 O.K 744.0V Acceptable





e8 /

PPA

Sol

ar P

V D

esig

n Im

plem

enta

tion

O&

M

15

Mar

shal

l Isl

ands

Mar

ch 3

1-A

pril

11, 2

008


（ 2 ） Earth resistance measurement

　　［ Test procedure ］

　　　 Measure the earth resistance.

　　　

　　［ Acceptance criteria ］

　　　 Earth resistance of 100 or less is acceptable.

Earth resistance

Item Measured value Result

Interconnection point 1.6Ω Acceptable

８・５ － field inspection items

Documents

８・５－ field inspection items