CARLO GAVAZZI ISMG 315, ISMG 320 User Manual

User Manual

ISMG 315 / ISMG 320

Three-Phase Solar Inverter

2

Safety

KEEP THESE INSTRUCTIONS FOR FUTURE REFERENCE – This manual contains

important instructions for Models ISMG 315 and ISMG 320 that shall be followed

during installation and future maintenance of the ISMG inverter.

Safety Precautions/Safety Notes

Only trained skilled and qualified electrical personnel shall carry out e electrical

installation, wiring, opening of the ISMG inverters. Even when no external voltage

is present, or the device is disconnected, the ISMG inverters can still store high

voltages and cause of electric shocks.

The temperature of the external heat sinks of the device can reach over 70°C

(158°F) in normal operation (Ambient temperature rating: 45°C / 113°F). There is

high risk of burn injury if these parts are touched.

The following general safety precautions must be observed during all operation

phases, service and installation of this device. Failure to comply with these safaty

precautions or specific warnings, elsewhere in this manual, violates safety

standards of design, manufacture, and intended use of the device. The

manufacturer assumes no liability for the customer’s failure to comply with these

requirements.

Safety Symbols

safety information prevent serious injuries or death to users

!

To reduce the risk of injury and to ensure the continued safe operation of this

product, the safety related information, contained in this manual are marked with

the below listed signs.

Warning, risk of electric shock

These

and/or installers.

Earth ground symbol

Caution

These information prevent damage to the product.

Intended Use

ISMG3 Series inverters shall be installed according to the specific norms and

regulations of your local building and safety department to meet the following

qualifications:



Electrical installation must be carried out correctly to meet the applicable

regulations and standards;



ISMG3 Series inverters shall be installed in a well ventilated environment and

protected against rain, condensation, moisture and dust;



ISMG3 Series inverters shall be installed in a permanent location according to

the instructions stated in this manual;



ISMG3 Series inverters shall operate according to the technical specifications

stated in this manual.

General Safety Precautions



Remove all conductive jewelry or personal accessories prior to installation or

service of the device, parts, connectors, and/or wirings.



Only trained and qualified personnel is authorised to mount, reconfigure or

repair this device.



Only licensed electricians are entitled to install permanently wired

equipments.



Make sure of standing on an insulated surface when working on the

operating device (i.e: avoid grounding of the person).



Instructions and information on cautions contained in this manual must be

carefully read and followed.



Use proper lifting techniques whenever handling enclosure, equipment or

parts.



The ISMG3 inverter must be provided with an equipment-grounding

conductor connected according to local norms and regulations.



The AC Neutral connection is only for voltage sensing and shall be neither

used to carry currents nor connected to ground inside the inverter.



The list does not contain all measures pertinent to the safe operation of the

device. If special problems arise which are not described in sufficient detail

for the purposes of the buyer, contact your local Carlo Gavazzi National Sales

company or specialized dealer or technician.

Safe Installation and Operation



Installation of the device must be in accordance with the relevant national or

local regulations. Correct grounding and short circuit protection must be

provided to ensure operational safety.



Read all instructions and caution remarks in the manual before installation.



Switch off the circuit breakers before installation and wirings. Avoid standing

on wet surfaces when working on the inverter.



PV arrays will be energized when exposed to light. Cover the arrays with

opaque (dark) material during installation and wiring. Always make sure the

DC switch is on the OFF position.



Check both of the AC and DC connections with a digital volt meter prior to

any installation or removal procedures.



Close the cover properly before switching on the circuit breakers.



Not to install the inverter exposed to direct sunlight



When no external voltage is present; the ISMG3 inverter can still contain high

voltages. There is still risk of electrical shocks.



Allow at least 5 minutes for the inverter to discharge completely after

disconnecting the AC and DC sources from the inverter.



External heat sinks can reach a relatively high temperature in normal

operation and cause skin burn injury if touched. Pay attention to it.



To prevent the risk of fire hazard, do not cover or obstruct the heat sink.



Any modification to the electrical system shall be carried out only by qualified

electricians.

!

Wiring the inverter

WARNING!

All electrical installation and the wiring methods shall be done in accordance with the relevant national or local electrical regulations and should follow the important safety instructions in this manual.

WARNING!

Make sure that you use suitable connecting cables for both the AC and DC wirings. The cables must be adequately dimensioned and suitably inert to temperature fluctuation, UV radiation and other possible hazards.

WARNING!

Reconfirm that all connections have been performed properly and all screws are properly tightened.

Connection of the DC cable

For DC Input Terminals, use wire size 10 to 16 mm2 (#8 to #6 AWG), 90°C

(194°F) Copper Wire.

CAUTION!

Identify the different polarity of DC voltage on each PV string and connect respectively to the input terminals. Make sure the DC voltage that PV arrays generate is equal or less than 850 VDC in any case.

WARNING!

Route the DC connection cables to the ISMG3 inverters away from any possible hazards that could damage the cables.

WARNING!

Hazardous voltage is still present on the device after disconnection of all PV DC inputs. Allow 5 minutes for the inverter to discharge the energy completely.

WARNING!

PV arrays will be energized when exposed to light. Cover the arrays with opaque materials during installation and wiring.

!

Connection of the AC cable

For AC Output Terminals, use wire size 6 to 10 mm2 (#10 to #8 AWG), 90°C

(194°F) Copper Wire.

WARNING!

Make sure that the circuit breaker of utility mains is switched OFF before connecting the power cables from the breaker to the AC connector.

Interaction with the Utility Grid

CAUTION!

The default interface protection has been verified according to the valid low-voltage national grid connection standards. Only the authorized installers can change the tripping-limit settings under the approval of the distribution network operator (DNO).

CAUTION!

Confirm the grid connection standard is selected correctly before tied with the grid (Std. DK5940 for Italy, VDE0126-1-1 for Germany or RD1663 for Spain). Please refer to the Section 3.3.5 Setting Operation for the selection of the grid connection standards.

CAUTION!

The default interface protection is saved permanently in the EEPROM and won’t be erased even if the inverter shuts down.

Repair and Maintenance

The inverter contains no user serviceable parts inside, except for the fans.

Only CARLO GAVAZZI LOGISTICS SpA trained staff is authorized to repair the

unit. Please return the equipment for further examination if the faults are not

caused by fans.

WARNING!

Not to make alterations or tamper assembly in the inverter unless expressly specified elsewhere in this Manual. Doing so may result in injury, electric shock, or fire and of corse void the warranty.

2

1.

2.

Contents

INTRODUCTION 3

1.1

1.2

1.3

1.4

INSTALLATION 12

2.1

2.2

2.3

2.3.1

G

ENERAL

S

PECIFICATIONS

F

EATURES

A

CCESSORIES

P

LACEMENT

M

OUNTING

W

IRING THE INVERTER

3

5

11

12

14

20

Connection of the AC cable................................................................27

3.

2.3.2

2.3.3

2.4

OPERATION 36

3.1

3.2

3.3

3.3.1

3.3.2

3.3.3 Produced Power Graphs.......................................................................52

3.3.4

Connection of the DC cable ...............................................................29

Connection of the Communication cable .........................................32

W

IRING INVERTER IN PARALLEL

O

VERVIEW

O

PERATION FEATURES

LCD D

LCD Backlight Indication ....................................................................41

Display messages flow .......................................................................43

Error Messages...................................................................................54

36

39

ISPLAY

40

35

3.3.5

3.4

3.4.1

3.4.2

Setting Operation ...............................................................................55

A

UTO TEST (ONLY FOR

Auto test PC Software ........................................................................58

Use Self-testing...................................................................................62

ISMG315IT

3

AND

ISMGT320IT) 57

4.

5.

3.5

3.6

TECHNICAL DOCUMENTATION 73

4.1

4.2

4.3

4.4

WARRANTY INFORMATION 80

E

RROR MESSAGES DESCRIPTION

T

ROUBLESHOOTING

O

UTLINE DRAWING

E

FFICIENCY

DE-

RATING OPERATION

MPP E

74

FFICIENCY

68

73

75

78

64

4

List of Figures

Fig1.1.1

Fig 2.1.1

Fig 2.2.2

Fig 2.2.3

Fig 2.2.4 Hook the Inverter on the mounting bracket and then fasten the screw

19

Fig 2.3.1

Fig 2.3.2

Fig 2.3.3

Fig 2.3.4

Fig 2.3.5

Fig 2.3.6

Grid Connected Solar System Overview...................................................4

Clearances required for ISMG3 inverter installation ..........................13

Inverter mounting bracket ...................................................................15

Fasten the mounting bracket ...............................................................16

Turn the DC disconnect switch OFF......................................................20

Loosen the screws .................................................................................21

Open the front lid of the wiring box.....................................................22

Removal of the covers for the cable through holes ............................23

Wiring box front view ...........................................................................24

Utility Grid Configuration .....................................................................26

Fig 2.3.1.1

Fig 2.3.2.1

Fig 2.3.2.2

Fig 2.3.2.3

Fig 2.3.3.1

Fig 2.3.3.2

Fig 2.3.3.3

Fig 2.3.3.4

Fig 3.3.1

Fig 3.3.1.1

Fig 3.4.1.1

Fig 3.4.1.3 Auto-test process ..............................................................................61

AC Terminal Block for AC cable connections ..................................27

ISMG3 Inverter supports two (2) independent PV strings....................29

PV Inverter Connections ..................................................................30

PV Strings in Parallel ........................................................................30

Positions of the communication ports and termination switch....32

RJ-45 Pins and Signals......................................................................33

RS-232 connection (ISMG-45S0918) ...............................................34

RS-485 connection ...........................................................................34

Front panel of the ISMG3 inverter .......................................................40

3 colours LCD backlight....................................................................41

Search for inverters..........................................................................58

Fig 4.1.1

Fig 4.2.1

Fig 4.2.2

Outline Drawing of ISMG3....................................................................73

Efficiency of the ISMG320 = 96.0% ......................................................74

Efficiency of the ISMG315 = 95.5% ......................................................74

Fig 4.3.1

Temperature de-rating curve of the ISMG320....................................75

Fig 4.3.2

Fig 4.3.3 Output Power v.s. Grid voltage of the ISMG320 ..................................77

Fig 4.4.1

Fig 4.4.2

DC Power curve of the independent PV string of the ISMG320.....76

MPP Efficiency of the two PV strings in parallel .................................78

MPP Efficiency of the two PV strings in individual..............................78

2

1. Introduction

1.1 General

The Carlo Gavazzi ISMG3 product family is a series of grid-connected photovoltaic

inverters which are designed to convert DC power generated by photovoltaic

arrays to AC power that is delivered into the utility grid. The ISMG315 and

ISMG320 are devices of the family with three (3) phases AC outputs for the

European market. The overview of the grid-tied solar energy system is shown in

Fig 1.1.1. ISMG3 inverters utilize the state-of-the-art technology to achieve the

purpose of high reliability and ease of use. In addition, ISMG315 and ISMG320

comply with the requirements of VDE0126-1-1, RD1663/RD661 and DK5940

Standards. Furthermore the 3-phase ISMG3 inverters are certified to comply with

the Standard EN50178 and EN55022 EMC Regulations with Class A device.

The ISMG3 inverter is designed to operate automatically once it is installed and

commissioned correctly according to the technical specifications. When the DC

input voltage generated by the photovoltaic arrays raises above the minimum

MPPT voltage setting, the embedded controller starts and goes into the system

initialization mode. If the DC input voltage goes above the PV Start voltage point,

the inverter will go into Checking mode (Riso check) and monitor all parameters

needed for grid connection. During this time, the ISMG3 inverter is not generating

AC power yet. Once all conditions necessary for grid connection are satisfied, the

ISMG3 inverter goes into the Grid/MPP mode and begins feeding the AC power

into the grid. When the input DC voltage falls below the pre-set threshold voltage

setting, the ISMG3 inverter will then shut off the output AC power. And the

inverter will shut down itself when the DC input voltage is under the minimum

3

MPPT voltage setting. The ISMG3 inverter will be awakened again automatically

when the input DC voltage rises above the minimum MPPT voltage point.

We appreciated your choice of Carlo Gavazzi ISMG3 inverters for your power

conversion devices in your solar power system. This document contains the

information you need for the installation and settings of the ISMG3 inverters.

Therefore, it is strongly recommended to read this manual carefully before the

ISMG3 inverter installation and settings.

Fig1.1.1 Grid Connected Solar System Overview

4

1.2 Specifications

Specifications for ISMG315 and ISMG320

Name-Part number ISMG 315 ISMG 320

Grid output (AC)

Grid voltage, nominal 400VAC 3PH/N/PE

Grid voltage, operating range

320 ~ 460VAC

Grid frequency, nominal 50 Hz

Grid frequency, operating

48~52.5 Hz (adjustable)*

range

Nominal Output Power

15,000 W 20,000 W (19,990W**)

Maximum output power 16,500 W 22,000 W

Nominal Output Current

Maximum Output Current

21.8 A 29.0 A

28.2 A 31.9 A (31.88A**)

Waveform True sine

Power factor > 0.99 @ nominal power

Total Harmonic Distortion < 5 %

DC Component < 0.5 %

Phase Three Phase

Solar input (DC)

Maximum DC Power

17,300 W 23,100 W

Maximum input voltage 850 VDC

Input voltage range 300 ~ 850 VDC

MPP voltage range 400 ~ 850 VDC

PV start voltage 400 VDC (adjustable)

Nominal voltage 630 VDC

Nominal

input current 2x19.7A (39.4 A) 2x26.3A (52.5 A)

5

Maximum input current 2x21.6A (43.3 A) 2x28.9A (57.8 A)

General

Name-Part number ISMG 315 ISMG 320

Maximum efficiency

CEC efficiency

96.7 % 97.0 %

95.5 % 96.0 %

Night consumption < 1W

Environmental

Operating temperature range -25° ~ +60°C (-13° ~ +140°F)

Storage temperature range -25° ~ +70°C (-13° ~ +158°F)

Maximum full power operating

50°C (122°F) 45°C (113°F)

ambient

Relative humidity Max. 95 %

Mechanical

Outdoor enclosure IP55, ref. IEC 60529(2001)

Cooling Intelligent control fan

DC input - Accept wire size of 10 to 16 mm2

(#8 to #6 AWG)

Input & Output terminals

AC output - Accept wire size of 6 to 10 mm2

(#10 to #8 AWG)

Weight/Shipping weight 75 kg / 85kg (165.3 lb / 187.3 lb )

Dimensions (HxWxD) 890.5×751×245.5 mm (35.1×29.6×9.7 inches)

Shipping dimensions (HxWxD) 1130×900×700 mm (44.6×35.5×27.6 inches)

Interface

Communication RS232 and RS485

Display 128 * 64 graphic display

Certifications

Directive 2004/108/EC EN 55022(1998) : IEC/CISPR22

Electromagnet Compatibility

EN 61000-6-2(2005) EN 61000-6-4(2007) EN 61000-3-11(2000)

6

EN 61000-3-12(2004)

configured with the approval of the local utility

trip limits and may be

on the ISMG315IT and on the

Low-Voltage Regulation

Directive 2006/95/EC EN 50178(1997), covered by IEC 62103(2003)

VDE 0126-1-1(2006), RD 1663(2000) / RD 661

Network Monitoring

(2007), DK 5940(2007) / Enel Connections Guide (2008), Section F

RoHS Directive 2002/95/EC

* Some factory settings can be re-

provider. This inverter is provided with adjustable aggregated over 200kW on a single Point of Common Coupling.

** The

output power

capacity is limited to 19.99 kW

ISMG320IT according to the DK5940 for the Italian market only.

7

Adjustable voltage, Frequency and Reconnection Settings (1)

DK5940 VDE0126-1-1

Setting

Range Default Range Default

Over-frequency (Hz) 50.05~50.95 50.25 50.05~50.15 50.15

Over-frequency disconnection time (cycle)

Under-frequency (Hz) 49.05~49.95 49.75 47.55~49.95 47.55

Under-frequency disconnection time (cycle)

Over-voltage (Vac) 235~270 270 235~260 260

Over-voltage disconnection time (cycle)

Under-voltage (Vac) 188~225 188 188~225 188

Under-voltage disconnection time (cycle)

Dc injection tripping current (A)

Dc injection disconnection time (cycle)

1~3 3 1~8 8

1~4 4 1~8 8

1~8 8 1~8 8

0.10~0.60 0.60 0.10~0.80 0.80

1~4 4 1~8 8

Insulation resistance trip setting (MOhm)

PV start voltage (Vdc) 400~800 400 400~800 400

Reconnect delay* (s) 20~300 20 30~300 30

* Once a grid failure occurred, the ISMG3 inverter waits 20~600 seconds before

the next connection to the grid. The default setting is 20 seconds for DK5940 (Italy), 30 seconds VDE0126 (Germany) and 180 seconds for RD1663 (Spain).

0.5~10 1.0 0.5~10 1.0

8

Adjustable voltage, Frequency and Reconnection Settings (2)

RD1663 User

Setting

Range Default Range Default

Over-frequency (Hz) 50.05~50.95 50.95 50.05~54.50 50.95

Over-frequency disconnection time (cycle)

Under-frequency (Hz) 48.05~49.95 48.05 45.50~49.95 49.05

Under-frequency disconnection time (cycle)

Over-voltage (Vac) 235~249 249 235~276 264

Over-voltage disconnection time (cycle)

Under-voltage (Vac) 199~225 199 160~225 196

Under-voltage disconnection time (cycle)

Dc injection tripping current (A)

Dc injection disconnection time (cycle)

1~8 8 1~250 4

1~8 8 1~150 4

0.10~0.80 0.80 0.10~0.80 0.80

1~150 8 1~150 8

Insulation resistance trip setting (MOhm)

PV start voltage (Vdc) 400~800 400 400~800 400

Reconnect delay* (s) 180~300 180 20~600 20

* Once a grid failure occurred, the ISMG3 inverter waits 20~600 seconds before

the next connection to the grid. The default setting is 20 seconds for DK5940 (Italy), 30 seconds VDE0126 (Germany) and 180 seconds for RD1663 (Spain).

0.5~10 1.0 0.5~10 1.0

9

Measurement precision

Range

Resolution

Accuracy

Display Measurement

Input voltage (VDC)

Input Current (IDC)

Grid voltage (VAC)

Grid current (IAC)

Grid frequency (Hz)

Output power (W)

Energy yield (kWh)

0~900V 0.1V 0.3V ±2V

0~50000mA 100mA 15mA ±500mA

0~300V 0.1V 0.3V ±1V

0~60000mA 100mA 30mA ±500mA

45~65Hz 0.01Hz 0.001Hz ±0.02Hz

0~22000W 1W 1W ±50W

0~65535×103kWh 0.1kWh 2.2×10-6kWh 1%

10

1.3 Features



High conversion efficiency



Dual-MPP trackers (Can be connected in parallel)



IP55 enclosure (Outdoor)



Graphical display (Internal mini-datalogger)



Three-phase balanced outputs



Easy installation



Smart self-diagnosis



High power / small size ratio



High reliability @ competitive price



Conformity to VDE 0126-1-1 (ENS), RD1663/RD661



DK5940/Enel Connections Guide (2008), Section F

1.4 Accessories



Operation Manual (incl. warranty page) 1 pcs

Mounting Bracket 1 pcs

Fixing screws (bet. the inverter and bracket) 2 pcs

Cross jumper (for input terminal) 1 pcs

Auto Test Software CD-ROM 1 pcs



Mounting screws 10 pcs

11

2. Installation

2.1 Placement

∙ ISMG3 inverters, that must be vertically mounted, can be located indoor or

outdoor according to protection degree of enclosure IP55.

∙ Leave at least 50 cm (19.7 inches) of free space above and 100 cm (39.4

inches) below the inverter when installed outdoor. Allow 20 cm (7.9 inches)

between inverters when installing multiple inverters for better ventilation (see

Fig 2.1.1).

∙ Mount the inverter on a wall that is strong enough to withstand the inverter

with 75 kg weight.

∙ Avoid mounting the inverter on a location directly exposed to sunlight to

maintain the ambient temperature of the inverter within -25° and 60 °C (-13°

and 140°F). Humidity shall be within 0% and 95%.

12

WARNING!

Some parts of the cooling surface can reach temperatures over

70°C (158°F) when the inverter is in operation. Do not operate the

inverter where it exposes to flammables, explosive atmospheres or

close to combustibles or unknown materials that may result in

fire/expolsion danger.

WARNING!

Do not expose the inverter to the corrosive liquids and/or gases.



Keep DC wirings as short as possible to minimize power loss.



The mounting bracket should be fastened on a concrete or a masonry wall

with the recommended anchors.

Fig 2.1.1 Clearances required for ISMG3 inverter installation

13

2.2 Mounting

The steps listed below describe how to mount the inverter on the wall:

1. After taking out the inverter from the carton, the attached mounting bracket

shall first be removed from the inverter by following the steps shown in Fig

2.2.1 below.

Fig 2.2.1 To remove the mounting bracket from the inverter

14

2. Use the mount bracket (Fig 2.2.2) as a template to mark the location of the

holes to be drilled in the wall. After drilling the holes, the mounting bracket is

then held against the wall and fastened to the wall with anchors as shown in

Fig 2.2.3. (At least ten (10) screws required)

For mounting on wooden wall, the suggested diameter of screw is at least

6.35mm and the length is 25.4mm. The nut size needs to be at least 12.7mm.

A minimum of 10 screws are required to mount the bracket on wooden wall

For mounting on steal plate, the suggested screw size is M8x16. A minimum

of 8 screws are required to mount the bracket on steel plate

For mounting on cement wall, the suggested anchor screw with outer

diameter of 8mmx38.1mm is recommended. The nut size needs to be at least

12.7 mm. A minimum of 8 screws are required to mount the bracket on

cement wall

Fig 2.2.2 Inverter mounting bracket

15

Fig 2.2.3 Fasten the mounting bracket

16

3. Once the mounting bracket is fastened to the wall, the inverter can be

mounted and fastened on the bracket. Hook the inverter on the mounting

bracket flanges and slip down carefully to lock it in place. And then fasten the

inverter to the mounting bracket as shown in Fig 2.2.4.

17

18

Fig 2.2.4 Hook the Inverter on the mounting bracket and then fasten the screw

After the inverter has been hooked correctly on the bracket and fastened to the

mounting bracket, it is then possible to proceed with the wiring.

19

2.3 Wiring the inverter

It is necessary to open the front lid of the wiring box before wiring the inverter.

First, the DC disconnect switch must be turned OFF as shown in Fig 2.3.1. And

then remove the two screws on the right hand side; open the red colour front lid

of the wiring box as shown in the Fig 2.3.2 and Fig 2.3.3 below.

Fig 2.3.1 Turn the DC disconnect switch OFF

20

Fig 2.3.2 Loosen the screws

21

Fig 2.3.3 Open the front lid of the wiring box

After the door is opened, it is then possible to remove the covers of the Threaded

Conduit holes as shown in the Fig 2.3.4 for the DC and AC cables to be put

through the threaded conduit holes in order to connect the inverter.

22

Fig 2.3.4 Removal of the covers for the cable through holes

The following three sections describe the wiring for the AC, DC, and

communication ports. The wiring shall carried out in the wiring box for the

ISMG315 and ISMG320. There is a DC terminal block, two (2) RJ-45 connectors,

and one (1) AC terminal block in the wiring box as shown in Figure 2.3.5. The DC

terminal block is used to connect up to two (2) PV strings individually or in parallel

in the wiring box. The RJ-45 connectors are used for external communication to a

remote computer or terminal. The AC terminal block is used to connect to the

utility grid, through a circuit breaker and distribution panel, according to national

and local requirements.

23

Fig 2.3.5 Wiring box front view

24

WARNING!

All electrical work shall carried out in accordance with the local and

national electrical norms and should follow the important safety

precautions contained in this manual.

WARNING!

Make sure that suitable connecting cables are used for both the AC

and DC wirings. The cable must be adequately dimensioned and

suitably inert to temperature fluctuation, UV radiation and other

possible hazards. For DC wiring connection to the ISMG3 inverter,

use 10 to 16 mm2 (#8 to #6 AWG), 90°C (194°F) copper wire; For AC

wiring connection, use 6 to 10 mm2 (#10 to #8 AWG), 90°C (194°F)

copper wire.

WARNING!

PV arrays will be energized when exposed to light. Cover the arrays

with opaque (dark) material during installation and wiring and make

sure the DC switch is on OFF position (as in fig.2.3.1)

Before wiring the ISMG3 inverter, it is necessary to determine the utility

configuration that the inverter will be connected to. The ISMG315 and ISMG320

inverters shall be used in three-phase utility interconnection with neutral as well

as the ground as shown in Fig 2.3.6.

25

Note: When connecting the ISMG3 inverter to the utility, the grid voltage must be

compatible.

Fig 2.3.6 Utility Grid Configuration

26

2.3.1 Connection of the AC cable

Use the following procedures to wire the AC cables.

1. Open the Distribution panel and switch off the circuit breaker used to

connect the inverter to the grid.

2. Use 6 to 10 mm2 (#10 to #8 AWG), 90°C (194°F) copper wire for all AC wiring

connections to the ISMG3 inverter.

3. Connect the cable GND to the ground terminal labeled

4. Connect the cable N to the terminal labeled N of the AC terminal block.

or “PE”

.

Fig 2.3.1.1 AC Terminal Block for AC cable connections

5. Connect the cables of the utility grid phases: L1, L2 and L3, to the terminals

labeled “L1”, “L2” and “L3” of the AC terminal block correctly.

6. Tighten the screws with a torque of 3.0 Nm (27.6 lb-in).

7. Reconfirm that all connections have been performed properly as described

above and all screws are properly tightened.

27

WARNING!

Make sure that the circuit breaker to the mains utility is switched

OFF before connecting the power cable from the breaker to the AC

terminal block.

WARNING!

Each connection to an ISMG3 inverter must be installed with a

dedicated circuit breaker in the mains utility service panel. The

breaker must be sized in order to handle the rated maximum output

voltage and current of an ISMG3 Inverter. No other appliances may

be connected to the circuit breaker.

28

!

2.3.2 Connection of the DC cable

The wiring box of the ISMG3 inverter is designed to support up to two (2)

independent PV strings to be connected in the wiring box and then fed into the

inverter.

Fig 2.3.2.1 ISMG3 Inverter supports two (2) independent PV strings

CAUTION!

Overcurrent protection may be required depending on the type

and ratings of the PV module configured in your system. The

maximum DC input current is 43.3A for ISMG315 and 57.8A for the

ISMG320. The maximum DC current allowed per string is 21.6A for

ISMG315 and 28.9A for ISMG320.

CAUTION!

The +PV and –PV cables of a PV sting shall be connected to the DC

terminals labeled “+” and “-” respectively. The capacity of the

cables should be taken into account by system installers to

determine the proper rating of the PV string fuse or a fire hazard

may occur if there is short-circuit in a PV string.

29

There are two (2) terminals per PV string located inside the wiring box used for

the DC cable connections. Up to two (2) independent PV strings are supported by

the ISMG3 inverter. Therefore, there are four (4) terminals, two (2) of them are

labeled with “+” and other two (2) are labeled with “-”, in the wiring box for DC

cable connections as shown in Fig 2.3.2.2 and Fig 2.3.2.3. All the screws for the

cable connections shall be tightened with a torque of 3.5 Nm (35.5 lb-in).

Fig 2.3.2.2 PV Inverter Connections

Fig 2.3.2.3 PV Strings in Parallel

30

!

NOTE: The ISMG3 inverter with Dual-MPP tracker is designed to be applied

to a variety of different configurations. In most cases it is

recommended to link the two PV strings into a single hole to obtain

the highest efficiency. Please consult with your installation servicer

and see how to connect, as show in Fig 2.3.2.3.

CAUTION!

PV arrays are energized when exposed to light. Use safe working

practices when working on PV arrays.

WARNING!

Route the DC cables to be connected to the ISMG3 inverters away

from any possible hazards that could damage the cables.

WARNING!

Hazardous voltage is still present on the ISMG3 inverter after

disconnection of all PV DC inputs. Allow 5 minutes for the device to

discharge the energy completely.

CAUTION!

Make sure that the DC input voltage generated by the PV arrays

must be equal to or less than 850 VDC in any condition, especially

in cold weather conditions, or it will cause damage to the ISMG3

inverter.

31

2.3.3 Connection of the Communication cable

The ISMG3 inverter supports two common data interface standards, RS-232 and

RS-485 that will be used to communicate to a remote computer or terminal

equipped with RS-232 or RS-485. Only one of the communication interfaces can

work at a time. As shown in Figure 2.3.3.1, there are two RJ-45 connectors, RJ45-R

and RJ45-L, which are located on the bottom of the enclosure. The pin numbers of

the RJ-45 connectors and the corresponding signals are described in Figure 2.3.3.2

below. If the RS485 is used as the external communication interface and the

inverter is the last device within the RS485 chain connections, then the

termination switch shall be put to ON position (shown in Figure 2.3.3.4). Users

shall open the front lid of the wiring box to switch the termination switch to ON

position. The termination switch is default set to OFF position.

Fig 2.3.3.1 Positions of the communication ports and termination switch

32

RJ45-L

Top view

Pin 1 TXD (RS232) 2 RXD (RS232)

18

3 Not used 4 GND 5 GND 6 Not used 7 TX A (RS485) 8 RX B (RS485)

RJ45-R

18

Top view

Pin 1 Factory reserved 2 Factory reserved 3 5V 4 GND 5 GND 6 5V 7 TX A (RS485) 8 RX B (RS485)

Fig 2.3.3.2 RJ-45 Pins and Signals

As shown in Fig 2.3.3.2, the RS-232 signal pins, TXD and RXD, are only on the

RJ45-L. Therefore, only the RJ45-L can be used to connect to the remote PC or

terminal when the RS-232 interface is selected. The cable with the part number of

ISMG-RJ45S0918, which is 180 cm (70.9 inches) in length, is dedicated for the

communications between a ISMG3 inverter and a computer when RS-232

interface is used. This cable has an RJ45 connector on one end and a RS-232 (DB9)

connector on the other end as shown in Fig 2.3.3.3. If RS-485 interface is selected,

then both RJ-45 connectors on the ISMG3 inverter can be used for the cascaded

RS-485 connections shown in Fig 2.3.3.4.

33

Fig 2.3.3.3 RS-232 connection (ISMG-45S0918)

Fig 2.3.3.4 RS-485 connection

34

2.4 Wiring inverter in parallel

ISMG3 inverters can be connected in parallel when more power is required. In the

parallel configuration, each inverter shall connect to its own PV array. It is not

recommended to connect one PV array to more than one inverter. This may cause

the inverter to work abnormally. The Fig 2.4.1 below shows the connections

between inverters and PV arrays in parallel configuration.

Fig 2.4.1 Parallel configuration of inverter

35

3. Operation

voltage point, the inverter is powered up, and enters the

displayed

on the LCD. In this operation mode, the inverter sets the

, and detects all parameters

that will be stored for future use. This stage takes only a few

ter will wait until the DC input

voltage point to enter the

3.1 Overview

The control electronics will be active as soon as the DC (PV) voltage reaches

“minimum MPPT” voltage point which is around 200VDC. The ISMG3 inverter is

then powered up and will show “Illumination” on the LCD, complete the system

initialization and wait for the DC voltage to reach the “PV start” voltage point

which is 400VDC. When the DC voltage reaches the “PV start” voltage point, the

inverter will enter “Checking” mode and then go on-line with the mains grid

(“Grid/MPP” mode) if all necessary conditions for grid connection are checked

and fulfilled. If the DC input voltage falls below the “pre-set threshold” point, the

inverter will shut off its output AC power and go back to “Illumination Low” mode

providing the DC voltage remains above the minimum MPPT voltage point. When

the DC voltage goes under the “minimum MPPT” voltage point, the inverter will

shut down itself.

There are five main operating modes described in detail below.

Illumination: When the DC input voltage goes above the “minimum MPPT”

system initialization procedure with “Illumination”

initial values, runs diagnostics

seconds and then the inver

voltage reaches the “PV start”

“Checking” mode.

36

Checking:

In this operation mode, the inverter checks all parameters on

nditions must be fulfilled and last for a certain

period of time, then the system will enter the Grid/MPP

is under

inverter

, turn the display

inverter continues to

to AC

stop

any

detected in the operating mode

on

the

state, stop feeding power to the grid, and then jump

executes a preset sequence. When

a

system fault mode

and enter checking mode. Some faults, like component

ff operation in

malfunction,

both AC and DC sides to ensure that connecting to the mains

is safe. All co

mode. If any parameter, except the DC voltage that

the “PV start” voltage, does not meet the criteria the

goes to “System Fault” mode.

Grid/MPP: The inverter will turn on the AC relays

backlight into green colour, and start feeding the AC power to

the grid. In this operating mode, the

convert the DC power generated by the PV array in

power that is then fed into the grid. The inverter will

feeding the power and go back to checking mode if

conditions for grid feeding mode is not satisfied anymore.

System Fault: When fault(s) occurs and are

described above, the inverter will display “System Fault”

the LCD (the display backlight turns to red) and exit

current

into the fault mode which

the faults have been cleared and do not appear anymore for

preset period of time, the inverter will exit

failure, will cause the inverter going into the “System idle”

mode. This condition requires maintainance sta

order to be cleared.

System Idle: Once the inverter has detected a major fault or

37

it will go into the “System idle”

mode and stop feeding the

This state requires

and put the

power to the grid for safety reasons. Normally this is a failure

that cannot be removed by the user.

maintainance staff operation in order to be reset

inverter back to normal operation.

38

3.2 Operation Features

1. Anti-Islanding protection

When an “islanding” condition is detected, for instance the utility grid

falls or is disconnected by mean of the mains disconnector, the inverter

will stop feeding the power on the AC output. An “island” is defined as a

grid tied inverter maintaining operation and feeding power to a load that

is isolated from the utility power source. This situation on the ISMG

inverters causes an automatic shutdown of the inverter. This is a safety

feature which is primarily meant to prevent electric shock hazard to

personnel who might have shut down the Utility grid in order to make

maintainance operations on it.

2. Unitary Power Factor:

The ISMG3 inverter intent is to feed the power with a unitary power

factor (PF = 1) to the utility during operation. The inverter continues

sensing the phase of the utility voltage and builds the output current

waveform in phase with the utility voltage.

3. Maximum Power Point Tracking:

In order to find the most efficient way of utilizing the solar energy,

ISMG3 inverters are designed to track and absorb the maximum power

from the PV array. The Maximum Power Point Tracking (MPPT) function

is employed in the embedded control software to achieve this intended

purpose.

39

3.3 LCD Display

The ISMG3 inverter has a 128 x 64 graphic LCD Display with three (3) colours

backlight, to display various information of the inverter such as the operating

status/settings, input/output data, cumulated power, and error messages.

furthermore, there is a keypad with 4 pushbuttons for users to select the

information to be displayed on the LCD from one of the categories of “System

Status”, “Energy Production”, and “Error Message”. The User can change, under a

password protected menu, some of the settings by selecting the “Edit Settings”.

As long as the DC input voltage is above the minimum MPPT voltage, the LCD

continues to display the information, the flow is described below in this section.

Fig 3.3.1 Front panel of the ISMG3 inverter

40

3.3.1 LCD Backlight Indication

There are three (3) colours: white, green, and red, of LCD backlight. The colour

will change according to the inverter operation status as shown in Figure3.3.1.1.

The explanation of the status and the corresponding colours of the backlight are

described in the following table.

Mode：：：：Grid/MPP

Mode：：：：Illumination

Mode：：：：Illumination Vac：：：：230/230/230V

Vac：：：：230/230/230V Fac：：：：50.00Hz

Fac：：：：50.00Hz Pac：：：： 0W

Pac：：：： 0W

03/27 06:50:25

Mode：：：：Grid/MPP Vac：：：：230/230/230V

Vac：：：：230/230/230V Fac：：：：50.00Hz

Fac：：：：50.00Hz Pac：：：：20000W

Pac：：：：20000W

03/27 13:50:25

Fig 3.3.1.1 3 colours LCD backlight

Mode：：：：SystemFault

Mode：：：：SystemFault Vac：：：：230/230/230V

Vac：：：：230/230/230V Fac：：：：50.00Hz

Fac：：：：50.00Hz Pac：：：： 0W

Pac：：：： 0W

03/27 15:20:45

LCD Backlight Indication Table

41

LCD backlight Operating status Description

White

Green

Initialization

Illumination

Checking

Grid/MPP

Derating Reduce the AC power feeding.

The inverter sets the initial values and detects all parameters.

The low Sun irradiation can not start the inverter.

The inverter monitors all the system parameters.

The Inverter is feeding AC power to the grid.

The system has encountered a minor

Warning

warning, but it continues to feed the AC power to the grid.

Red

The inverter has detected a

SystemFault

SystemIdle

Programming The program is being updated.

recoverable failure and will re-start on its own as soon as normal condition is restored. An unrecoverable failure occurred; The unit requires service personnel in order to verify the system and restore normal operation.

42

3.3.2 Display messages flow

The display messages flow changes according to the procedure we are into. There

are 3 main operation procedures: regular procedure, fault procedure or idle

procedure.

The regular procedure is when the system goes from power-on (illumination low),

system check, and then Grid/MPPT mode without any fault condition detected. If

during the system check, a fault condition that could be cleared is detected, the

system will turn to the fault procedure. The system will return to regular

procedure as soon as the fault condition disappears. An example of this situation

could be the “island” condition: if the grid voltage goes off and then after some

time goes on again, the ISMG3 goes into fault state, but the fault condition is

cleared when the power returns. If a fault cannot does not self restore, the

system will enter the idle procedure and will need a service staff to clear the fault

and reset the system. The following paragraphs explain how the display works in

the different operating modes.

Illumination:

When the DC input voltage rises above the “minimum MPPT” voltage point but

under the “PV start” voltage point, the ISMG3 inverter is powered up and will

show the model name (e.g. ISMG315), serial number, firmware versions, and the

complied standards, on the Display. After around five (5) seconds, the Main Menu

with four (4) selections, System Display, Graphic Method, Error message, and

Setting, that user can select through the up/down buttons will be displayed on

the LCD. Three seconds later, if no selection is made, the “System Display” will

automatically go to “Illumination” Mode on the LCD and stop there until the

system goes into the “Checking” mode. Together with the Mode (Illumination),

43

the LCD also displays the three-phase AC voltages, Frequency, and AC output

DK5940

power on the AC side.

PVMate 20E

S/N：：：：020010070001

Ver. M00 & S00

Std.

5 seconds ↓

System Display

System Display Graphic Method

Graphic Method

Graphic Method Error message

Error message

Error message Setting

Setting

3 seconds ↓

Mode：：：：Illumination

Mode：：：：Illumination Vac：：：：230/230/230V

Vac：：：：230/230/230V Fac：：：：50.00Hz

Fac：：：：50.00Hz Pac：：：： 0W

Pac：：：： 0W

03/27 23:50:25

44

Checking:

When the DC input voltage reaches the “PV start” voltage point, the inverter goes

into the “Checking” Mode. In this operation mode, the inverter will check “Riso”,

all parameters on both AC and DC sides, and then the AC relay to ensure that

connecting to the mains is safe. After all conditions are satisfied for a preset time,

which can be set from 20 to 600 seconds, then the system will enter the

Grid/MPP mode and feed AC power to the grid. During the Checking mode, the

display will follow the information flow as shown in the diagram below.

Mode：：：：Check 300s

Mode：：：：Check Riso

Mode：：：：Check Riso Vac：：：： 0/ 0/ 0V

Vac：：：： 0/ 0/ 0V

Mode：：：：Check 300s Vac：：：：230/230/230V

Vac：：：：230/230/230V

Fac：：：：00.00Hz

Fac：：：：00.00Hz Pac：：：： 0W

Pac：：：： 0W

03/27 23:50:25

30 seconds ↓

Mode：：：：Checking

Mode：：：：Checking Vac：：：：230/230/230V

Vac：：：：230/230/230V

Vac：：：：230/230/230V Fac：：：：50.00Hz

Fac：：：：50.00Hz

Fac：：：：50.00Hz Pac：：：： 0W

Pac：：：： 0W

03/27 23:50:25

3 seconds ↓

Fac：：：：50.00Hz

Fac：：：：50.00Hz Pac：：：： 0W

Pac：：：： 0W

03/27 23:50:25

XXX seconds ↓

Mode：：：：Check Relay

Mode：：：：Check Relay Vac：：：：230/230/230V

Vac：：：：230/230/230V

Vac：：：：230/230/230V Fac：：：：50.00Hz

Fac：：：：50.00Hz

Fac：：：：50.00Hz Pac：：：： 0W

Pac：：：： 0W

03/27 23:50:25

3 seconds ↓

45

Grid/MPP:

After the system has entered into the Grid/MPP (grid feeding) mode, the inverter

will feed the AC power to the mains grid and show on the display, with green

lolour backlight, the operating mode, the actual AC voltage, frequency, and. The

other data such as the cumulated energy, the DC input power of each PV string,

and the AC output power of each phase, can be displayed on the LCD by press the

“DOWN” button of the keypad as shown in the figure below.

By using the “UP”, “DOWN”, “ESC”, and “OK” buttons, users may be able to view

the data they want.

(a)Press “UP” or “DOWN” key to select the monitoring parameter.

(b)Press “ESC” key return to previous state.

(c)Press “OK” key to confirm.

46

Mode：：：：Grid/MPP

Mode：：：：Grid/MPP Vac：：：：230/230/230V

Vac：：：：230/230/230V

Vac：：：：230/230/230V Fac：：：：50.00Hz

Fac：：：：50.00Hz

Fac：：：：50.00Hz Pac：：：：20000W

Pac：：：：20000W

03/27 23:50:25

Enter “ DOWN ” key ↓

Mode：：：：Grid/MPP

Mode：：：：Grid/MPP Eac_ty：：：： 999kWh

Eac_ty：：：： 999kWh

Eac_ty：：：： 999kWh Eac_to：：：：999999kWh

Eac_to：：：：999999kWh

Eac_to：：：：999999kWh CO2_rd：：：：999999kg

CO2_rd：：：：999999kg

03/27 23:50:25

Enter “ DOWN ” key ↓

Mode：：：：Grid/MPP

Mode：：：：Grid/MPP VPV_A：：：： 630.0 V

VPV_A：：：： 630.0 V

VPV_A：：：： 630.0 V I PV_A：：：： 18.2 A

I PV_A：：：： 18.2 A

WPV_A：：：：11466 W

03/27 23:50:25

Enter “ DOWN ” key ↓

Mode：：：：Grid/MPP

Mode：：：：Grid/MPP Vac_L1：：：：230.0 V

Vac_L1：：：：230.0 V

Vac_L1：：：：230.0 V I ac_L1：：：： 31.8 A

I ac_L1：：：： 31.8 A

Pac_L1：：：： 7314 W

03/27 23:50:25

Enter “ DOWN ” key ↓

Mode：：：：Grid/MPP

Mode：：：：Grid/MPP Vac_L2：：：：230.0 V

Vac_L2：：：：230.0 V

Vac_L2：：：：230.0 V I ac_L2：：：： 31.7 A

I ac_L2：：：： 31.7 A

Pac_L2：：：： 7291 W

03/27 23:50:25

Enter “ DOWN ” key ↓

Mode：：：：Grid/MPP

Mode：：：：Grid/MPP VPV_B：：：： 630.0 V

VPV_B：：：： 630.0 V

VPV_B：：：： 630.0 V I PV_B：：：： 18.2 A

I PV_B：：：： 18.2 A

WPV_B：：：：11466 W

03/27 23:50:25

Enter “ DOWN ” key ↓

47

Mode：：：：Grid/MPP

Mode：：：：Grid/MPP Vac_L3：：：：230.0 V

Vac_L3：：：：230.0 V

Vac_L3：：：：230.0 V I ac_L3：：：： 31.9 A

I ac_L3：：：： 31.9 A

Pac_L3：：：： 7337 W

03/27 23:50:25

Derating:

When power de-rating is detected, the “Derating” message will be displayed on

the LCD as shown in the picture below. There are five possible situations that may

cause output power derating. The ISMG detects only one derating situation at the

time. Therefore, users shall also view other information through the RS485

interface if they want to precisely identify the reason that causes derating, when

the “Derating” message is displayed. Please refer to Section 4.3 De-rating

Operation for additional information regarding the situations that can cause

power derating. The VDE0126 requires that if the maximum AC output power

(110% of the rated power can normally occur together with VacH) lasts for 10

minutes, the inverter shall shut off the output. In the ISMG315/320 inverter, it is

designed to lower the output power (output power de-rating) before shutting off

the output. If the VacH message goes away, the inverter will not turn off the

output. If the VacH message remains, the inverter will shut off its output

according to the VDE0126 norm.

Mode：：：：Derating

Mode：：：：Derating Vac：：：：230/230/230V

Vac：：：：230/230/230V Fac：：：：50.00Hz

Fac：：：：50.00Hz Pac：：：：16888W

Pac：：：：16888W

03/27 13:50:25

48

Warning:

There are three possible warning messages that can be displayed on the Display

when exespected situations occur in Grid/MPP mode:



When the system has encountered a problem in accessing to the

internal EEPROM memory device, the “EEPROM” warning message

will be displayed



The ISMG3 has encountered a communication error with the

external terminal, the “COMM” warning message will be displayed

on the LCD;



If one and/or two o the built-in fans stop running, the warning

message, Fan Lock A, Fan Lock B or Fan Lock AB, will be displayed. If

all warnings occur simultaneously, the warning messages will be

displayed in the following order with three (3) seconds interval:

COMM => EEPROM => Fan Lock A (or B or AB)

Mode：：：：Fan Lock AB

Mode：：：：Fan Lock AB Vac：：：：230/230/230V

Vac：：：：230/230/230V Fac：：：：50.00Hz

Fac：：：：50.00Hz Pac：：：：16888W

Pac：：：：16888W

03/27 13:50:25

49

System Fault:

When the system goes into the fault mode, it will shut off the output AC power,

disconnect from the mains grid, and have the “System Fault” message displayed

on the LCD with the backlight in red color as shown in the figure below. The

fault(s) that cause the system going into the fault mode will be recorded. Users

can press the “ESC” button to go into the main menu and then select the “Error

message” to view the error message(s) of the fault(s). Users may refer to the Error

Message Table on Section 3.6 for the explanations of the error messages. When

the fault will clear, the inverter will automatically try to go into the Checking

mode and then the Grid/MPP mode to feed AC power to the grid.

50

System Idle:

When the ISMG3 inverter goes into the Idle mode, only service staff can clear this

mode and reset the inverter. When in the idle mode, the ISMG3 inverter will shut

off the output AC power, disconnect from the mains grid, and have the “System

Idle” message displayed on the LCD with the backlight in red color as shown in the

figure below. The fault(s) that cause the system going into the idle mode are

recorded. Users can press the “ESC” button to go into the main menu and then

select the “Error message” to view the error message(s) of the fault(s). Please

refer to Error Message Table on Section 3.6 for explanations of error messages.

51

2

3.3.3 Produced Power Graphs

Press the “ESC” button to return to the main menu, then press the “Down” key

until the “Graphic Method” is highlighted and then press the “OK” key to confirm

the selection.The daily production graph will be displayed on LCD as shown in the

figure below. This trend graph shows the output AC power produced on a

specified date. The date is indicated on the upper right corner. In order to go to

another date press the “OK” button first and then press the “DOWN” or “UP” until

the required date is reached. The ISMG3 inverter has enough memory to record

the daily chart for up to 31 days.

System Display

System Display Graphic Method

Graphic Method

Graphic Method Error message

Error message

Error message Setting

Setting

Press “OK” key ↓

kWh

5

5 4

4

4 3

3

3 2

2

2 1

1

2 4 6 8 10 12 14 16 18 20 22 24

2 4 6 8 10 12 14 16 18 20 22 242 4 6 8 10 12 14 16 18 20 22 24

07/31

Press “DOWN” key ↓

5

If order to display the monthly chart, first press “ESC” key and then press the

"DOWN" key to change to the monthly chart as shown below.

On the upper right

corner, it shows the present month. To change month press “OK” first and then

press “DOWN” or “UP” key to switch the months. The ISMG3 may record monthly

charts for up to 12 months.

kWh

200

150

100

50

kWh

10 20 30

2010/07

53

3.3.4 Error Messages

To review the recorded error messages, users shall select "Error Message", on the

main screen, by pressing the “Down” or “Up” key from and then press the "OK"

key to confirm. The LCD will then display the last error message recorded on the

LCD with the date and time that the fault occurred. To see the next recorded error

message, press “DOWN” or “UP” key to browse through the pages. The ISMG3

may record up to 99 error messages in the memory.

System Display

System Display Graphic Method

Graphic Method

Graphic Method Error message

Error message

Error message Setting

Setting

Press “OK” key ↓

1. 2010 / 07 / 01

1. 2010 / 07 / 01 17：：：：45：：：：35

17：：：：45：：：：35

Error message

Press “DOWN / UP” key

54

3.3.5 Setting Operation

Some of the Inverter parameters can be re-configured from the built in panel. To

chenge the paramaters select "Setting" from the main menu and then confirm by

pressing the "OK", as shown below. The standard selection is password protected.

The other settings such as the date, time, language, minimum start voltage,

start-up time, buzzer ON/OFF, communication baud rate, and RS485 address, are

not password protected. The interface protection standard change: DK5940,

VDE 0126, or RD1663, shall be carried out by qualified and professional service

staff. For this purpose a specific password ie required. When the setting change is

completed, the inverter must be restarted to have the new settings effectively

executed.

The parameters that can be re-configured from the panel are described as

follows:



Date: Date setting.



Time: Time setting.



Language: Display language selection.



Start V: Adjust the minimum startup voltage.



Start Sec: Set the delay time at start-up.



Alarm: Turn "ON" or "OFF" the buzzer.



Standard: Interface protection standard setting according to

local/national requirements.



Baudrate: Set the communication serial port baud rate.



RS485 Addr: Set the RS485 address.



Auto Test: Perform auto-test function. (Only for ISMG315IT and

ISMGT320IT)

55

System Display

DK5940

YES

DK5940

YES

System Display

System Display Graphic Method

Graphic Method

Graphic Method Error message

Error message

Error message Setting

Setting

Press “ OK ” key ↓

System Setting

Password：：：： 000000

Press “UP/DOWN/OK” key ↓

System Setting

Standard：

Standard： Baudrate：：：： 9600

Baudrate：：：： 9600

Baudrate：：：： 9600 RS485 Addr.：：：： 250

RS485 Addr.：：：： 250

Press “UP/DOWN/OK” key ↓

System Setting

Auto Test：：：：OFF

Press “ ESC ” key ↓

：

：：

System Setting

Date：：：：2010/07/01

Date：：：：2010/07/01 Time：：：： 15:25:35

Time：：：： 15:25:35

Time：：：： 15:25:35 Language：：：：English

Language：：：：English

Press “UP/DOWN/OK” key ↓

System Setting

Start V ：：：： 400.0V

Start V ：：：： 400.0V Start Sec：：：： 300S

Start Sec：：：： 300S

Start Sec：：：： 300S Alarm：：：：OFF

Alarm：：：：OFF

Press “UP/DOWN/OK” key ↓

EXIT Setting：

Press “DOWN/OK” key

：

：：

56

3.4 Auto Test (Only for ISMG315IT and ISMGT320IT)

This Auto Test function is required according to the Italian Standard DK5940. With

the Auto Test function, users may be able to verify the AC voltage and frequency

(grid side) monitoring function. When the Auto Test function is running, the

inverter will not provide AC power to the mains grid. The Auto Test routine shall

be in the order as:

Maximum AC voltage threshold test for each phase

Minimum AC voltage threshold test for each phase

Maximum AC frequency threshold test for each phase

Minimum AC frequency threshold test for each phase

PVMate 15E/20E

3-phase AC output

R

DC input

Main relay

S

T

There are two relays series connected for each phase of the AC output as shown

above. The Main relay will be closed (activated) when running each threshold test

for each phase. After the threshold test is complete the Main relay will be

released (de-activated). The Auto Test functionality and procedure is described in

the following sections.

57

3.4.1 Auto test PC Software

The Auto Test software as an accessory provided with the inverter and should be

installed in a computer which is connected to the inverter through the “RJ45-L

port” (the RJ45 port on the left-hand side of the Inverter). Once the software is

installed successfully, the .EXE file “ISMG315/320 Auto Test” has been created in

the sub-directory “Start\Programs menu”. Users may start the Auto Test function

by double clicking “ISMG315/320 Auto Test.exe” file . The program starts with a

search routine for all inverters connected to the computer, a pop-up window will

appear on the PC screen: “Search for inverters” as shown in Figure 3.4.1.1. If no

inverters are found, the “Search again” warning message will be displayed on the

screen. A re-confirm that the connections are correct within the RS485

communication loop is required. Then click on the “Search for inverters” button

to search again. If at least one inverter is found, the serial number and the status

of the inverter will be shown on the screen as shown in Figure 3.4.1.2.

Fig 3.4.1.1 Search for inverters

58

Fig

3.4.1.2 Communicated successfully

Only one inverter at the time can be selected to run the Auto Test function even if

more than one inverter is found. Users can choose the inverter by highlighting the

serial number and then click the “Start Auto Test” button to run the Auto Test

function, which will be performed in the order as shown in Figure 3.4.1.3 and

described below.

a. Maximum AC voltage (VacH) threshold ( phase order: R → S → T ) b. Minimum AC voltage (VacL) threshold ( phase order: R → S → T ) c. Maximum AC frequency (FacH) threshold ( phase order: R → S → T ) d. Minimum AC frequency (FacL) threshold ( phase order: R → S → T )

The standard threshold values and the trip time related to the specified sub test,

will be displayed on the PC screen, before the Auto Test starts. The slew rate of

the threshold values, either increase or decrease, are ≤ 0.05 Hz/s for frequency

and ≤ 1 V/s for voltage starting from the maximum (or minimum) threshold value.

During the Auto Test the threshold value changes linearly and the measured

59

voltage or frequency of the AC grid will be displayed on the PC screen. The

maximum/minimum threshold values and the accepted trip time defined in

DK5940 are as follows:

a. Maximum AC voltage threshold: 270 V; < 80 ms b. Minimum AC voltage threshold: 188 V; < 160 ms c. Maximum AC frequency threshold: 50.25 Hz; ≤ 60 ms d. Minimum AC frequency threshold: 49.25 Hz; ≤ 80 ms

The threshold value will decrease (or increase) from the maximum (or minimum)

threshold value toward the measured value of the AC grid. When the threshold

value reaches the measured AC voltage or frequency of the grid the inverter will

disconnect the AC line by de-activate the Main relay. The inverter will measure

the time duration when the command has been sent and the disconnection is

recognized. This time duration must be less than the trip time defined.

(a)

Start Auto-test

60

(b) Auto-test completed

Fig 3.4.1.3 Auto-test process

After all sub tests are completed, a popup window “All tests are finished” will

appear on the PC screen and the “OK” key, on the PC screen, has to be pressed in

order to stop the Auto Test software.

61

3.4.2 Use Self-testing

It is also possible to run the Auto Test function without a computer connected.

From the main display menù, select “Setting” and then select “Auto Test” and

press “OK” to perform the Auto Test function as shown below. (Please refer to

Section 3.3.5)

System Setting

Auto Test：：：：ON

Press “ OK “ key ↓

AUTO TEST

. . . . . . . .

When the Auto Test function starts running, the “AUTO TEST” message will be

displayed on the Display as shown above and stay until the Auto Test function

ends with “PASS” or “FAIL” message on the display. If the test fails, it will also

show the tested item which didn’t pass the threshold test.

AUTO TEST

<< FAIL >>

<< PASS >>

L1 Vac High

or

62

!

CAUTION!

If any one of these sub tests fails, the inverter will go into the “fault

mode” and stop the test. The inverter will stay in “fault mode” and

will not restart unless the test is re-run and it is Passed

CAUTION!

The only purpose of the Auto Test function is only to check the

operation of the interface protection functionality of the inverter.

It will NOT change any actual threshold and trip setting.

63

3.5 Error Messages description

when a fault occurs, the inverter will stop feeding the AC power to the utility grid

and display the error message on the LCD. Qualified service staff shall analyse,

measure, and if needed proceed with debugging, according to the error message,

in order to restore normal operation. It is recommended to screen out the fault

condition(s) by referring to the table below and then remove the fault

condition(s) to have the inverter back to normal condition and continue to feed

AC power to the utility. Please contact Carlo Gavazzi local National Sales

Company, your distributor or service representative if the same error message

persists.

64

Error Messages Table

Error Message Description

GridNA No AC voltage is detected on the utility grid side.

VacH The AC voltage of utility grid is over the upper limit.

VacL The AC voltage of utility grid is under the lower limit.

FacH The AC frequency of the utility grid is over the upper limit.

FacL The AC frequency of the utility grid is under the lower

limit.

Phase Loss One or two phases are missing (AC voltage is not present

on that / those phase).

L2, L3 Swap. L2 and L3 phases are reversed.

Drift Fac Islanding is detected.

FastEarthCurrent The drastic change of the leakage current has been

detected.

SlowEarthCurrent The leakage current has exceeded a safe operating limit.

DCInjectCurH The DC current injected into the AC grid is over the upper

limit.

Iac_Max. Over current on the grid side.

IacH The AC current is over the upper limit.

65

Error Message Description

Riso Low The insulation resistance between PV array and the ground

is below the safe operating limit.

VpvH The DC voltage of PV array is over the upper limit.

IpvH Over current on the DC side.

PpvH Over power on the DC side.

VdcbusH Internal DC bus voltage is over the upper limit.

VdcbusL Internal DC bus voltage is below the lower limit.

Temp. High The internal temperature of the inverter exceeded the safe

operating limit.

CPUs diff.High Internal measurements from both CPU’s are differ from

System Error General system failure.

Relay Open

each other.

Relay Short

Relay Fault

Vdcbus Fault DC/DC converter failure.

Output relay failure.

66

Error Message Description

RCMU Fault Leakage current measurement device failure.

I/P HCT Fault

O/P HCT Fault

HCT Fault

Idc-inj. Fault DC injection current monitoring function failure.

SPI Error Internal communication failure.

EEPROM Fault

FanLock_A

FanLock_B

EEPROM test failed. *warning message

Cooling fan / fans stopped running. *warning message

Input/Output current sensor failure.

Comm. Error External communication failed. *warning message

Offset Fault Internal reference voltage failed, +1.5VA, +1.5VB.

CalDataLoss Loss of the Calibration data.

Model Error The hardware MODEL and the CPU software versions are

not compatible.

Version Error The firmware version is not correct.

67

3.6 Troubleshooting

The error message(s) are displayed on the LCD and recorded in memory when the

ISMG3 inverter has encountered a fault situation. Some critical faults will cause

the inverter to automatically shut off the output AC power. For safety reason, the

inverter will not re-start until the fault will be cleared. In general, we suggest to

follow the steps described below to identify and solve the problems.

1. Make sure that the ISMG3 inverter is correctly connected to the mains utility

and PV arrays following the connection procedures described in this manual.

2. Try to identify and solve the problem based on the troubleshooting table

below.

3. If the problem cannot be identified and solved, please contact your local

Carlo Gavazzi National Sales Company, distributor or service representative

for assistance.

68

Trouble Shooting Table

Restart the inverter again;

Inform professional service

staff if failure does not

Error Message

Comm. Error

DCInjectCurH



Possible Causes

External communication

malfunction

Calibration parameters

are deviated

Internal circuits

malfunction

AC current sensor

malfunctions

The default settings are

Disposal Measures

Restart the inverter again;



Inform professional service

staff if failure does not

restore

Inform professional service



staff in order to check the

calibration parameters CPUs diff.High



restore

Inform professional service



inappropriate

staff to check the settings

69

Error Message

EEPROM Fault

FanLock_A

FanLock_B

FastEarthCurrent

SlowEarthCurrent



Possible Causes

EEPROM's parameters

are unrecognized

Fan malfunction

DC or AC wires

insulation is damaged

and it causes high

ground fault current

AC feed lines are

Disposal Measures

Inform professional



service staff to update

the EEPROM's

parameters

Inform professional



staff to replace the fan

Check the DC and AC



wire insulation

Check the AC wirings



GridNA

(Loss of Mains)

HCT Fault

Iac_Max.

IacH

disconnected

AC switch/breaker is



open

Grid power blackout



DC or AC current sensor



malfunctions

Mains voltage drops



suddenly

The inverter



malfunctions

Close the AC switch/



breaker after clearing

the faults

Wait until the grid is



restored

Restart the inverter;



Inform prof. staff if

failure does not restore

If seldom occurring it



can be ignored

Inform professional



staff if failure does not

restore

70

;

Inform professional staff if

at least

Error Message

Idc-inj. Fault

Offset Fault

L2, L3 Swap.

Model Error

Phase Loss

RCMU Fault



Possible Causes

Internal circuit

malfunctions

L2 and L3 cables are wired

reversed

Default settings are wrong

One of the AC wirings is

disconnected

Residual current

protective device

malfunctions

Disposal Measures

Restart the inverter again;



Inform professional staff if

failure does not restore

L2 and L3 wirings shall be



swapped

Inform professional staff to



replace the inverter

Check the AC wirings



Restart the inverter again

Relay Open

Relay Short

Relay Fault

Riso Low

SPI Error

Temp. High

AC relay malfunctions



Moisture or conductive



matter between DC lines

and earth.

Internal communication



malfunctions

Insufficient Air circulation



failure does not restore

Remove matter and or dry



the wet area then restart

the inverter again

Restart the inverter again



and Inform professional

staff if failure does not

restore



Allow a clearance of

20cm at least from walls or

other devices for air intake

71

and exhaust

Inform

Error Message

VacH

VacL

FacH

FacL

(Mains voltage or

frequency is

beyond the limit)

Ambient temperature is



too high



Possible Causes

AC voltage or

frequency exceeds

the default settings

Mains voltage or

frequency is unstable

The settings are

Ensure the ambient



temperature is below 60°C

Disposal Measures

Wait until the grid is back to



stable condition

Request the utility supplier to



improve and then inform

professional staff to change

the settings.

Inform professional staff to



VdcbusH

VdcbusL

Vdcbus Fault

Version Error

VpvH

IpvH

PpvH

inappropriate

The inverter



malfunctions

Firmware version is



incompatible

PV array voltage



exceeds the

permissible value

check the settings.

Restart the inverter and



professional staff if failure

does not restore

Reinstall the firmware



according to the instruction

Disconnect the DC source and



inform the system installer to

check the configuration of PV

arrays

72

4. Technical Documentation

4.1 Outline Drawing

Fig 4.1.1 Outline Drawing of ISMG3

73

4.2 Efficiency

The efficiency of the ISMG315/320 is shown in Figure 4.2.1 and Figure 4.2.2

below.

Fig 4.2.1 Efficiency of the ISMG320 = 96.0%

Fig 4.2.2 Efficiency of the ISMG315 = 95.5%

74

4.3 De-rating Operation

Here below are described the different situations in which the Inverter will limit

the output power in order ensure the system operates in a safe condition.

Temperature

The ISMG3 inverter monitors the heat sink temperature. If the temperature

exceeds 70°C (ambient temperature is around 45°C), the the output power

will be reduced until the temperature falls under the critical value. The ISMG3

inverter will shut down the AC power output to the grid if the temperature

reaches 85°C. If this situation occurs frequently, it is necessary to check

whether the inverter is installed in an adequate location, with good

ventilation and not exposed to direct sunlight.

Fig 4.3.1 Temperature de-rating curve of the ISMG320

75

Input DC current excess

When the input current from the PV strings is about to exceed the maximum

value, the ISMG3 inverter will limit it to the safe operating value in order to

prevent damages to the inverter. If this situation occurs frequently, it is

necessary to check whether the PV arrays are properly configured according

to the Inverter DC current limit.

Fig 4.3.2 DC Power curve of the independent PV string of the ISMG320

Output AC power excess

The maximum power that the ISMG3 inverter feeds to the grid is limited

according to the specifications listed in Section 1.2. The Output current of is

limited by the ISMG3 inverter is in case the AC voltage becomes too high in

ordet to maintain the power within the specified limit.

76

Output AC current

The maximum current that the ISMG3 inverter feeds to the grid is limited

according to the specifications listed in Section 1.2.

Fig 4.3.3 Output Power v.s. Grid voltage of the ISMG320

77

4.4 MPP Efficiency

The ISMG315/320 supports up two (2) PV strings that can be either connected in

parallel, feeding into a single MPP tracker, or connected individually to each MPP

tracker. The efficiencies of the 2 configurations: two(2) PV strings connected in

parallel and connected individually are shown in Figure 4.4.1 and Figure 4.4.2

respectively.

Fig 4.4.1 MPP Efficiency of the two PV strings in parallel

Fig 4.4.2 MPP Efficiency of the two PV strings in individual

78

WARNING!

PV arrays are always energized when exposed to light therefore

hazardous voltage is still present on the terminal blocks and the PV

string fuse holders even the DC disconnect switch is switched OFF.

Please cover the PV arrays with opaque (dark) materials during the

inverter removal. Keep covered until the inverter is hooked back

and reconnected.

WARNING!

Hazardous voltage is still present on the device after disconnection

of all PV DC inputs. Allow 5 minutes for the inverter to discharge

the energy completely.

WARNING!

Check that all DC and AC switches are turned off for at least five (5)

minutes before opening the front covers of the inverter and the

wiring box and disconnect the DC and AC wires between them. The

wires that have been disconnected shall be wrapped with an

insulated material in order to prevent electrical shocks of the

service personnel and to avoid short circuits.

WARNING!

Not to keep any spare parts inside the wiring box.

79

5. Warranty information

Warranty Period

A period of 5 years is warranted from the date of your purchase of the ISMG3

series Products.

Additional 5 years warranty: warranty extension up to 10years can be purchased

separately within the term specified in the “warranty terms certificate” from

purchase date of the unit

Warranty Terms

The warranty terms of the ISMG3xx Inverters are specified in the “Warranty terms

and certificate” leaflet enclosed in the package of purchased unit.

Product Return Procedure

The product return procedure and terms are described in the “Warranty terms

and certificate” leaflet enclosed in the package of purchased unit.

On-site Inspection & Repair

The on-site Inspection & Repair procedure and terms are described in the

“Warranty terms and certificate” leaflet enclosed in the package of purchased

unit.

80

Your Notes :

81

CARLO GAVAZZI ISMG 315, ISMG 320 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual