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Inverters/Converters -- North America Requirement

Inverters/Converters – North America Requirement

1: Constructional Requirement

2: Testing Requirement

3: Document Requirement

4: Hot-discussion items

5: Q & A

10/22/2012 2

(Inverter: DC power to AC power)

10.26.2012 USA 3

ANSI/UL1741 (call out IEEE 1547 &1547.1 for grid protection and

power quality, etc.), NRTL certification

- Tests acc. to the standard and 2-4 factory inspections per year

- Test mark issued by TUV Rhinalnd TUVus

National Electrical Code (NEC 70)

California CEC (California Energy Commission)

- Third party measurments per CEC Guideline

- As a member of NRTL, TÜV Rheinland reports are accepted

Known regional requirements, certification regulations

10.26.2012 Canada 4

• CSA C22.2 No. 107.1 certificate

- Tests acc. to the standard and 2-4 factory inspections per

year

- Test mark mark issued by TUV Rhinalnd, cTUV

• Canada Electrical Code (CEC)

Known regional requirements, certification regulations

10.26.2012 Inverter/Converter 5

- Enclosure (including materials, NEMA rating, openings, hazard

protections, etc.) and the frame construction;

- Spacings and/or Cl & Cr (UL840);

- Switch, Disconnect Devices;

- Connections and wiring means;

1. Constructional Requirement (US & Canada)


- Grounding, over-current protection;

- Isolation of circuits (Input – Output – Control Circuits)

- Built-in GFDI, means of design (fuse, or solid-state devices);

- Components and insulation materials;

- Utility interaction (field adjustable tripping, etc.)

1. Constructional Requirement (US & Canada)

2. Testing Requirements (US & Canada)


- UL 1741 Testing:

- Temperature rise measurement , need to be tested at a

chamber of max. specified environment temperature if it was

marked more than 40C;

- Output short-circuit test

- GFDI verification test

- Hi-Pot Test



- IEEE 1547.1 part (call out part by UL 1741);

- Testing order (abnormal voltage – abnormal frequency –

synchronization – EMI – surge – repeat);

- Anti-islanding test;

- Harmonics and DC injection if no isolating transformer;

- Reconnection time;

- Open phase.



- Additional tests for Canada

- C22.2 #107.1 testing, which different to that of UL 1741, such

as grounding continuity/resistance measurement ;

- Grid-connection requirement, use IEEE 1547.1 test results



- Manufacturing and production tests (routine test):

- Dielectric Voltage-Withstand (Hi-Pot) Test;

- Utility Voltage and Frequency Variation Test.



- CEC testing and report for NRTL listed/certified inverters:

- Maximum continuous output power;

- Conversion Efficiency;

- Tare losses.

3. Document Requirements


- Rating and Nameplate;

- Warning, Cautionary Markings;

- Equipment Information and Instructions;

- Service Manual independent of User/Operation/Installation

manuals;

- Important Safety Instructions

3. Document Requirements


- Additional requirements for Canada:

- At least the Warning/Cautionary Markings in both English and

French;

- Manufacturing date, different wording to that of UL 1741, etc.

- More than one live circuit, etc.

- Others.

4. Hot-discussion Items


- Safety standard harmonization (UL62109-1) with IEC 62109-1:

Safety of power converters for use in photovoltaic power systems –

Part 1: General requirements

and IEC 62109-2:

Safety of power converters for use in photovoltaic power systems –

Part 1: Particular requirements for inverters

to be expected to be followed;



- New Standard: IEC 62477-1: 2012,

Safety requirements for power electronic converter systems and

equipment – Part 1: General

It has a better suitability than EN 50178/IEC 62103: Electronic

equipment for use in power installations, for non-PV products,

such as wind power converters (AC – AC), etc.



- Grid connection and power quality requirements

(differ by countries)

EN 50438: Requirements for the connection of micro-

generators in parallel with public low-voltage

distribution networks



- Transformer-less inverters

Conventional inverters normally have an isolation transformer either

built-in the unit or connected external to the AC output terminals.

While transformer-less inverter means the AC output circuits (which

may directly connected to the 120Vac/480Vac grid) are not isolated

to the DC input circuits.

What the standard(s) says about this case?

Please see IEC 62109-2, also it was adopted into UL 1741 as

section 88-100.



- Input working voltage over 600Vdc

Though UL 1741 does not specify the max. working voltage is

600V, due to the rating limits of components, the spacing table,

etc., once the input working voltage is more than 600Vdc,

additional evaluations are needed to verify the compliances.

(see Article 690.80 of NEC 70 too)

In Canada, CSA C22.2 # 107.1 stated that it applies to a unit its

rated voltage not exceeding 600 V. What we need to do in the

case of the DC input is up to 1000V?



- PV Arc-fault detection/interruption per UL 1699B (based

with UL 1699)

Article 690.11 of NEC 70 (2011) requires listed DC Arc-fault circuit

interrupter when the PV system working voltage is more than 80V.

IF the PV arc-fault protection means are built-in type in the inverter, it

shall meet that all that 4 requirements specified in 690.11 of NEC 70.



- Built-in meter accuracy

SGIP(Self-Generation Incentive Program) Handbook and

CSIP(California Solar Initiative Program) Handbook, etc. have meter

accuracy requirements for built-in meter within inverters.

(+/-2% or +/-5% per the applicable protocols of ANSI C12.1)

“The accuracy rating of the meter must be certified by an independent

testing body (i.e. a NRTL such as UL or TUV)”

5. Q & A


Contact :

Fred Z. Zhu

Phone: (925) 249-9123 ext. 186

Cell: (925) 918-5123

Email: [email protected]

inverters zhu

Documents

testing requirements

cec testing

canada c22

document requirements

regional requirements

additional requirements

test gfdi verification

test results