UL 62109-1

Safety of power converters for use in photovoltaic power systems – Part 1: General requirements

UL 62109-1

1 Scope and object

1.1 Scope

This part of IEC 62109 applies to the power conversion equipment (PCE) for use in Photovoltaic (PV) systems where a uniform technical level with respect to safety is necessary. This standard defines the minimum requirements for the design and manufacture of PCE for protection against electric shock, energy, fire, mechanical and other hazards.This standard provides general requirements applicable to all types of PV PCE. There are additional parts of this standard that provide specific requirements for the different types of power converters, such as Part 2 – inverters. Additional parts may be published as new products and technologies are commercialised.

1.1.1 Equipment included in scope

This standard covers PCE connected to systems not exceeding maximum PV source circuit voltage of 1 500 V d.c. The equipment may also be connected to systems not exceeding 1 000 V a.c. at the a.c. mains circuits, non-mains a.c. load circuits, and to other DC source or load circuits such as batteries. This standard may be used for accessories for use with PCE, except where more appropriate standards exist.Evaluation of PCE to this standard includes evaluation of all features and functions incorporated in or available for the PCE, or referred to in the documentation provided with the PCE, if such features or functions can affect compliance with the requirements of this standard.

1.1.1DV Modification in accordance with the following:

• Replace the maximum PV source circuit voltage of 1 500 V d.c. with 2 000 V d.c.

1.1.2 Equipment for which other requirements may apply

This standard has not been written to address characteristics of power sources other than photovoltaic systems, such as wind turbines, fuel cells, rotating machine sources, etc.NOTE 1 Requirements for other sources may be incorporated in the IEC 62109 series in the future.Additional or other requirements are necessary for equipment intended for use in explosive atmospheres (see IEC 60079), aircraft, marine installations, electromedical applications (see IEC 60601) or at elevations above 2 000 m.NOTE 2 Requirements are included for adjustment of clearance distances for higher elevations, but not for other factors related to elevation, such as thermal considerations

1.1.2DV Modification in accordance with the following:

Add new sentence before NOTE 1. “PV PCE with inputs for other non-PV power sources (not specifically addressed by this standard), shall address the normal and abnormal source specific operating characteristics including but not limited to; voltage range, current range, short circuit current, over-voltage, etc.”

1.2 Object

1.2.1 Aspects included in scope

The purpose of the requirements of this part of IEC 62109 is to ensure that the design and methods of construction used provide adequate protection for the operator and the surrounding area against:

• electric shock and energy hazards;
• mechanical hazards;
• excessive temperature hazards;
• spread of fire from the equipment;
• chemical hazards;
• sonic pressure hazards;
• liberated fluids, gases and explosion hazards.

NOTE Servicing personnel are expected to have the necessary knowledge and skill to use reasonable care in dealing with hazards associated with the operation, repair and maintenance of this equipment. Based upon this premise, this standard provides only limited requirements (for example markings or guarding) intended to protect service personnel from hazards that may not be apparent even to trained personnel. 1.2.2 Aspects excluded from scope

Aspects not covered by this standard include, but are not limited to, the following:

• functional reliability, performance or other properties of the equipment not related to safety;
• effectiveness of transport packaging;
• EMC requirements;
• installation requirements, which are covered by local and national installation codes.

NOTE This standard does provide requirements for PCE intended to ensure that the PCE can be installed in a safe manner, including requirements for installation instructions provided with the product.