Xantrex PV 20208 User Guide

OPERATION and MAINTENANCE

MANUAL

for

MODEL PV-20208

20 KW Grid-Tied

Photovoltaic Inverter

Document #151119

Revision B November 10, 2000

IMPORTANT SAFETY INSTRUCTIONS

SAVE THESE INSTRUCTIONS - THIS MANUAL CONTAINS IMPORTANT INSTRUC-

TIONS FOR TRACE TECHNOLOGIES MODEL PV-20208 GRID TIED PHOTOVOLTAIC INVERTER THAT SHALL BE FOLLOWED DURING INSTALLATION AND MAINTENANCE OF THE PV-20208.

Xantrex Technologies Inc./Trace Technologies Corp.

161-G SOUTH VASCO ROAD

Livermore, CA 94550

(925) 245-5400

T able of Contents

Section 1: Product Description

Introduction Major Components Interconnection Standards Compliance Specifications Equipment Symbol

Section 2: Safety

Safety Features Isolation Procedure Anti Island Protection

Section 3: Installation And Initial Turn-On

Isolation Transformer Requirements T orque and Wire Gauge Specifications Installation Instructions Interconnection Wiring Initial Turn On Procedure

Section 4: Operation

Description of System Operation Operator Interface Panel (LED and LCD) Example of Normal System Operation

Section 5: Troubleshooting

General Fault Conditions and Troubleshooting Fault Clearing Fault Descriptons and Troubleshooting

Section 6: Preventative Maintenance

Isolation Procedure Turn-On Procedure

Section 7: Drawings and Major Parts Lists

System Schematic, Grid Tied PV Inverter , PV-Series Assembly Drawings And Major Parts Lists Envelope Drawing, Grid Tied PV Inverter , PV-20208 UL Listing Document, April 25, 2000 UL Listing Card, September 8, 2000 Accessories

SECTION 1 PRODUCT DESCRIPTION

INTRODUCTION

The Trace Technologies Model PV-20208 is a 20KW Grid Tied Photovoltaic Inverter. It utilizes advanced power electronics to allow interface of a photovoltaic array with a utility grid. The PV-20208 is a highly integrated assembly, consisting of an inverter bridge and associated control electronics all on a single board. The PV-20208 control software provides for complete overall system control with a variety of protective and safety features.

MAJOR COMPONENTS

The major components of the PV-20208 are identified in Drawing No. 151121.

Main Enclosure

The enclosure (shown in Figure 1-1) is NEMA-4 rated. The PV-20208 enclosure contains the Integrated Bus Board, output line filter (insuring that the PV-20208 line currents and voltages meet IEEE519 harmonic distortion requirements), control power transformers, and A/C contactor (PV-20208 A/ C output to the grid). Also found within the enclosure are the system protection devices (control power circuit fuses). The front door of the enclosure contains the operator interface panel (three LED’s or LCD and an on/off switch).

1-1

Figure 1-1

Figure 1-2

PV-20208 Photovoltaic Inverter

Operation and Maintenance Manual

DOCUMENT: 151119

SECTION 1 PRODUCT DESCRIPTION

CAUTION

The fuses within the PV-20208 are intended for protecting the PV-20208 control circuitry only. They are not intended to provide protection for the PV array or external cabling.

Integrated Bus Board The PV-20208 design makes use of a fully integrated bus board as shown in Figure 1-2. The bus board assembly is mounted to an aluminum extrusion heat sink, which mounts through an opening in the back of the enclosure. The power electronics is comprised of a six pack of IGBT devices, mounted to the heat sink. The bus board is mounted on top of the IGBT six pack device, and is supported through a series of standoffs attached to the heat sink.

The bus board contains all of the necessary control functions to drive the (attached) switching transistors. The bus board contains the following functional circuits: D/C control power supplies (+5V, +/15V and four isolated +15V sources for the IGBT’s), A/C and D/C high voltage measurement, A/C and ground current measurements, contactor and indicator controls, discrete input sensing (on/off switch), and closed loop PWM modulators. The bus board contains a micro-controller chip to perform the lowlevel control functions associated with the collection of measurement and driving the pulse width modulators.

A plug in DSP module controls the bus board. The DSP module is designed to the industry standard, PC-104 specification, and is used to perform the majority of the calculations needed to control the bus board. The most significant tasks are: control of PV-20208 electromechanical components and power electronics converters, signal conditioning (digital filtering and transformations), and communication with the operator interface panel and system sensors.

The PV array ties directly to the DC bus. The inverter controller manages the transfer of power between the DC bus and the utility grid.

INTERCONNECTION STANDARDS COMPLIANCE

The PV-20208 has been tested and certified by Underwriters Laboratories to be in compliance with UL1741 Static Inverters And Charge Controllers For Use In Photovoltaic Power Systems, as well as IEEE-P929 Recommended Practice For Utility Interface Of Photovoltaic (PV) Systems.

IEEE-P929 provides guidance regarding equipment and functions necessary to ensure compatible operation of photovoltaic systems which are connected in parallel with the electric utility. UL1741 is the test procedure performed by Underwriters Laboratory on the PV-20208 to verify it meets the recommendations of IEEE-P929. Refer to both documents for details of these recommendations and test

procedures.

1-2

PV-20208 Photovoltaic Inverter

Operation and Maintenance Manual

DOCUMENT: 151119

SECTION 1 PRODUCT DESCRIPTION

SPECIFICATIONS

The PV-20208 has been designed for photovoltaic power systems, which operate within the following specifications. Application of the PV-20208 in a manner inconsistent with these specifications may cause damage to the PV-20208 and other system components, and is a violation of the terms of the warranty.

egatloVeniLCAlanimoN%01±,CAV802

tnerruCeniLCAmumixaM )egatlovenilwolta(SMRA86.16

ycneuqerFeniLlanimoNzH5.0±,zH06

daoLCAsuounitnoCCAv802@WK0.02

egnaRegatloVVPCDV006-033

tnerruCmumixaMVPCDA8.36

noitarugifnoCVP

dnuorglartuen

ralop-ibro,dednuorgevitagenraloponoM

erutarepmeTgnitarepO*C°05ot02-

erutarepmeTegarotSC°05ot04-

gnitaRerutarepmeTtneibmAmumixaMC°05

ytidimuHevitaleRgnisnednoc-noN,%59oT

noitavelEteef006,6evobadetareD

)sehcnini(snoisnemiD41X52X03

thgieW.sbl571.xorppA

epyTerusolcnE4AMEN

eliFgnitsiLLU653991E-eliF

*If ambient temperature is between -20 to 0° C, the unit must be powered up in standby for at least one hour prior to going on-line.

EQUIPMENT SYMBOL

Chassis ground – Customer supplied system ground connection point. This symbol may be found near a stud within the main enclosure. It is provided as a location to bond the electrical system equipment ground.

1-3

PV-20208 Photovoltaic Inverter

Operation and Maintenance Manual

DOCUMENT: 151119

SECTION 2 SAFETY

SAFETY FEATURES

WARNING

The PV-20208 enclosure contains exposed high voltage conductors. The enclosure door should remain closed, except during maintenance or testing. These servicing instructions are for use by qualified personnel only. To reduce the risk of electric shock, do not perform any servicing other than that specified in the operating instructions unless you are qualified to do so. Do not open the cabinet door if extreme moisture is present (rain or heavy dew).

Front Panel Indicators

The PV-20208 incorporates three colored LED indicators, used to show the current operating state of the inverter. The indicators have the following meanings:

• Red: Fault Mode - The inverter has sensed an abnormal condition. To reset the unit (clearing the

fault condition), cycle the on/off switch (see below).

• Amber: Sleep Mode – The inverter is waiting for sufficient PV voltage to start the inverter.

• Green: Operator Mode - The inverter is active and generating A/C current.

On/Off Switch

The PV-20208 incorporates a maintained position on/off switch located on the front door of the enclosure. Under normal conditions, the on/off switch in the on position. Turning the switch to the off position will initiate a controlled shutdown of the PV-20208 and open the main contactor within the unit. The PV-20208 is prevented from being restarted until the on/off switch is turned back to the on position. Cycling the on/off switch will reset the PV-20208 and attempt to clear any system fault.

Main Enclosure Door

The front door of the PV-20208 main enclosure is pad lockable. It is recommended that the PV-20208 enclosure door be padlocked during normal operation.

WARNING

The PV-20208 does not incorporate a door interlock switch. Please make sure the unit is powered down, and isolated from the utility grid and PV panels, prior to opening the enclosure door. (Allow 5 minutes for any stored potentials to be discharged, prior to opening the unit). The front door of the PV-20208 main enclosure is pad lockable. It is recommended that the PV-20208 enclosure door be padlocked during normal operation.

Fault Reporting

Any fault conditions are reported to the operator interface. If the PV-20208 is equipped with LED’s, the red LED will light and the green LED will flash the corresponding number of the fault. If the PV20208 is equipped with the LCD option, the LCD will display a text description of the fault. Refer to Section 5, Troubleshooting, for detailed descriptions of system fault conditions.

PV Ground Fault Detection

The PV-20208 is equipped with ground fault detection circuitry and control. The single point of PV

2-1

PV-20208 Photovoltaic Inverter

Operation and Maintenance Manual

DOCUMENT: 151119

SECTION 2 SAFETY

system ground must be routed through CT1 on the main control board (see section 3, installation and section 7, system schematic for further detail). Upon detection of 1.5 amps of ground fault current, the PV-20208 executes an orderly shutdown, and annunciates a ground fault at the operator interface. The PV-20208 will remain faulted until the ground fault is remedied and cleared at the operator interface (see section 5, troubleshooting).

ISOLATION PROCEDURE

The following procedure should be followed to de-energize the PV-20208 for maintenance:

WARNING

The terminals of the PV input may be energized if the arrays are energized. In addition, allow 5 minutes for all capacitors within the enclosure to discharge after disconnecting the PV-20208 from AC and DC sources.

1. Turn the on/off switch to the off position.

2. Open the PV array disconnect switch (if present).

3. Open the AC interface disconnect (if present).

4. Open the isolation transformer circuit breaker.

5. Install lockout devices on the isolation transformer circuit breaker and PV disconnect switch (if present).

ANTI ISLAND PROTECTION

A digital phase-shift-loop (PSL) circuit is implemented in the DSP inverter controller to prevent “Islanding” of the PV-20208.

The DSP continuously makes minor adjustments to the power factor phase angle above and below unity. In the event of a utility outage, these adjustments destabilize the feedback between the inverter and the remaining load, resulting in an over/under frequency or voltage condition. The PV-20208 then performs an orderly shutdown. The fault condition will remain until the utility voltage and frequency have returned to normal for 5 minutes.

This method has been extensively tested and proven to exceed the requirements of UL 1741.

2-2

PV-20208 Photovoltaic Inverter

Operation and Maintenance Manual

DOCUMENT: 151119

SECTION 3 INSTALLATION AND INITIAL TURN-ON

ISOLATION TRANSFORMER REQUIREMENTS

The PV-20208 is required to have an isolation transformer wired between the inverter AC output and the utility interconnection. Any standard dry-type isolation transformer is compatible with the PV20208 as long as the inverter side is rated for a minimum of 20KVA continuous duty.

WARNING

Check with the local utility of jurisdiction when selecting the winding configuration of the isolation transformer. Individual utilities may have unique requirements related to isolation transformer wiring. Some winding configurations may keep the PV-20208 from detecting a loss of phase condition on the utility system which may allow potentially lethal voltage to be present on the open phase wirings.

Inverter Side Isolation Transformer Requirements The inverter side transformer windings may be configured either delta or WYE, and must be rated for 208 VAC. Trace Technologies recommends using a delta wound transformer to avoid installation mistakes. If a WYE wound transformer is used to interface with the PV-20208, and the PV array is grounded, the neutral (X0) must be left floating. If the neutral is tied to ground, the inverter will not function properly , and may be damaged.

Utility Side Isolation Transformer Requirements The utility side isolation transformer windings may be configured either delta or WYE, and must be rated for the utility voltage at the point of utility inter-connection. Check with the utility of jurisdiction when selecting an isolation transformer configuration. If a WYE wound transformer is used to interface with the utility , it is not necessary to connect the neutral (X0) to ground. The PV-20208 is a balanced, three phase, current sourcing inverter, and only operates with the presence of a stable utility voltage. Single phase grounded loads which may be present between the transformer and utility, will maintain their existing ground reference at the utility distribution transformer . Grounding the neutral of a WYE wound transformer may create an “open delta” condition, depending on the utility configuration. This

condition may keep the PV-20208 from detecting a loss of phase condition on the utility system, which may allow potentially lethal voltage to be present on the open phase wiring.

Contact your Xantrex/Trace Technologies distributor if you have any questions regarding isolation transformer requirements.

TORQUE AND WIRE GAUGE SPECIFICATIONS

The following torque specifications are to be used on all electrical interfaces made during installation of the PV-20208.

T orque Table

3-1

eziStloBrokcolBlanimreTgnitteSeuqroT

1-6MmN9.5/.sblni25

23126tumwahS/zarreFmN6.31-3.2/sblni021-02

PV-20208 Photovoltaic Inverter

Operation and Maintenance Manual

DOCUMENT: 151119

SECTION 3 INSTALLATION AND INITIAL TURN-ON

The following table shows acceptable wire gauges to be connected to the PV-20208 AC and DC inputs.

Wire Gauge Table

noitanimreTGWAegnaReriW

)CA(rotcatnoC01#-3#

)CD(kcolBnoitubirtsiD41#-0/2

INSTALLATION INSTRUCTIONS

CAUTION

All wiring methods shall be in accordance with the National Electrical Code ANSI/ NFPA 70. All power conductors interfacing to the PV-20208 should be sized in accordance with the National Electric Code ANSI/NFP A 70 and local codes. Large gauge wire must have a minimum bend radius dependent upon the wire gauge (refer to the National Electric Code, Article 373-6B). Take care to keep the wire bundles away from any sharp edges which may damage wire insulation over time. Trace Technologies recommends using No. 6 AWG, 105 degrees C, minimum, copper wire for all connections with the PV-20208.

Ventilation Considerations

1. Maintain a minimum 6” clearance above and below the PV-20208 for proper cooling fan operation.

2. Maintain a minimum 1” clearance to the left and right of the PV-20208.

Installation

1. The unit must be mounted at least 3’ off the ground, and 12” above any horizontal surface.

2. Screw two 3/8” x 3-1/2” long lag bolts into existing studs in the wall (16-inch mounting center) at lower mounting level on PV-20208. Lag bolts should be horizontally level with each other. Leave a minimum of 1” of bolt protruding from the wall.

3. Place the PV-20208 bottom mounting ears, shown in Figure 3-1 and Figure 3-2 onto installed lag bolts. (See following page.)

4. Hold the unit against wall and install upper lag bolts (3/8” x 3-1/2”). Tighten bolts firmly.

5. Tighten lower lag bolts while unit is held in place.

6. Install two 1-1/2” liquid tight connectors (included with the PV-20208) where shown in Figure 3-3. (See following page.)

3-2

Figure 3-1

PV-20208 Photovoltaic Inverter

Operation and Maintenance Manual

DOCUMENT: 151119

SECTION 3

CT1

INSTALLATION AND INITIAL TURN-ON

Figure 3-2

Figure 3-3

Array Grounding and Ground Fault Detection

If grounding the PV array is required for monopolar or bipolar arrays, jumper TB1-2 to a (PV-) cabinet ground stud. If ground fault detection is required, route this jumper through CT1 located on the lower right hand corner of the control board (see the system schematic for further detail). This must be the only point of PV grounding for the PV-20208 and the ground fault detection system to function properly .

LIQUID TIGHT CONNECTORS

CAUTION

The input and output circuits are isolated from the enclosure, and that system grounding, if required by sections 690-41 and 690-42 of the National Electric Code, ANSI/NFPA 70, is the responsibiliy of the installer.

3-3

PV-20208 Photovoltaic Inverter

Operation and Maintenance Manual

CONTROL BOARD & CT1

DOCUMENT: 151119

SECTION 3 INSTALLATION AND INITIAL TURN-ON

Phase-Sequencing The PV-20208 is equipped with an automatic phasedetection control algorithm. This allows the utility interface conductors to be connected in any sequence convenient at the time of installation. Upon system initialization at power-up, the PV-20208 determines the phase sequence of the utility connection and configures the modulator drivers accordingly .

INTERCONNECTION WIRING

CAUTION

To reduce the risk of fire, connect only to a circuit provided with 90 amperes maximum branch circuit overcurrent protection in accordance with the National Electrical Code, ANSI/NFPA 70.

The following wires for connecting the PV-20208 to external devices are not provided by Xantrex/Trace Tech-

MAIN CONTACTOR

nologies: (See wiring diagram on the following page.)

• 3-Phase 208 VAC inverter output (main contactor, see picture) to terminals of the 208 VAC delta side of isolation transformer. If the inverter side of the isolation transformer is configured

WYE and the PV array is grounded, the neutral must be left floating. Ground loops will exist when the inverter starts switching, which will cause the inverter to shut down due to phase over-currents and may result in damage to the PV-20208. Also, insure that this neutral is not bonded to the isolation transformer frame.

• System ground to the isolation transformer chassis ground.

• Isolation transformer grid side terminals to line circuit breaker (or the AC disconnect switch if

present).

• PV frame ground to PV-20208 enclosure chassis ground stud.

• PV-20208 enclosure chassis ground stud to the electrical distribution system ground.

• PV+ to the inverter enclosure terminal block TB1-1.

• PV- to the inverter enclosure terminal block TB1-2.

Install all wires listed above. Refer to the system schematics in Section 7 for more detailed terminal locations.

3-4

PV-20208 Photovoltaic Inverter

Operation and Maintenance Manual

DOCUMENT: 151119

SECTION 3 INSTALLATION AND INITIAL TURN-ON

Frame

PV Array

Ground

Inverter

PV-20208

X1 H1 X2 H2 X3 H3

PV+

Isolation

Transformer

PV-

(Optional)

Trace Combiner Box

Wiring Diagram

3-5

PV-20208 Photovoltaic Inverter

Operation and Maintenance Manual

To Single Point Electrical

Distribution System Ground

Breaker

Line Circuit

DOCUMENT: 151119

+ 26 hidden pages