The introduction of IEC 62368-1 to the European product standards framework means some changes for how audio/visual products and information technology equipment (ITE) can be designed and powered.
Unlike the outgoing incident-based standards—IEC/EN/UL/CSA 60065 (Audio, Video & Similar Electronic Apparatus) and IEC/EN/UL/CSA 60950-1 (Information Technology Equipment)—IEC 62368-1 is a hazard-based standard. This means 62368-1 does not prescribe how the product should be designed or manufactured to avoid specific unsafe incidents. Instead, the standard defines hazardous energy sources upfront, requires manufacturers to address these hazards with safeguards, and sets requirements for testing the effectiveness of these safeguards to demonstrate compliance.
With this in mind, manufacturers of
audio/video equipment and information technology equipment have more
flexibility in the design of their product under 62368-1 compared to prior
product standards—as long as they can demonstrate that the risks are
well-addressed by the design of the product and its safeguards.
Risks to Power Source Circuitry
To be compliant with IEC 62368-1, there are two key hazards originating on AC power lines that power sources and circuitry must be equipped to handle:
●
Overcurrent, also referred to as “excess
current,” refers to when the electric current present in a conductor exceeds
the normal intended load. This can generate excessive heat, risking fire or
damage to the equipment. Overcurrents may be caused by a short circuit, ground
fault, arc fault, or overloading the circuit.
●
Transient overvoltage, sometimes called a
“surge,” is a brief, high-magnitude peak of voltage. Transient overvoltage can
result in disruption to connected equipment, degraded or damaged equipment, and
downtime. These are typically caused by lightning strikes or switching
operations.
There are multiple ways to mitigate these hazards, some of which are discussed below. But with the new hazard-based approach offered by IEC 62368-1, manufacturers can choose the safeguards that make the most sense for their specific product and its power source.
Safety Features and Technologies to Address Power Source Hazards
There are multiple ways to protect a product
against these risks, especially within the context of a hazard-based standard
like IEC 62368-1. However, there are several technologies and components that
may be involved:
●
Fuse - protects against overcurrent, i.e.
short circuit and overload conditions, by breaking the circuit if too much
current is flowing, protecting the wiring and the connected device(s) from
damage
●
Metal oxide varistor (MOV) - a zinc oxide
grain structure that protects against overvoltage conditions, e.g. surges, by
shunting the current from the excessive voltage away from sensitive areas that
could be damaged in the surge
●
Transient-voltage-suppression (TVS) diode - a
clamping diode structure that protects from overvoltage by “clamping” the
voltage spikes; the TVS often works faster than varistors or gas discharge
tubes (GDT)
●
Silicon Diodes for Alternating Current (SIDACs) - a semiconductor device with controllable silicon architecture that
protects sensitive components from overvoltage;
● Gas discharge tubes (GDT) - a crowbar-type device that protects against overvoltage by conducting excess electrical current into a glass-contained gas mixture, which becomes ionized when the voltage spikes; it conducts quite a bit of current for its size, but it does take longer than other devices to trigger and has a limited lifespan
An expert compliance partner like G&M Compliance can help you navigate the complex product design, testing, and certification process. There are a number of questions to answer, starting with whether or not your product needs 62368-1 certification in the first place; whether your product needs to meet requirements for 62368-1 and IEC/EN 62368-3; and whether you should pursue a CB scheme or another route for compliance.
Contact G&M Compliance to discuss your product and target markets today, and get started on the fastest path to market!