New Industry Products

20A TÜV-Certified Power Supply Achieves SIL 3 Safety

March 21, 2019 by Scott McMahan

Phoenix Contact's premium QUINT Power line now includes a single-device solution that meets functional safety applications up to Safety Integrity Level (SIL) 3. The new QUINT 20+ power supply (see image above) has an integrated decoupling MOSFET and double overvoltage protection circuitry to meet rigorous SIL 3 safety regulations without the need for external redundancy.

The new power supply offers a selectable output characteristic curve and features (selective fuse breaking) SFB technology.

Safety Integrity Level (SIL) is a measure of safety system performance in terms of the probability of failure on demand. The SIL rating of a device represents the degree of reliability in which the product has to fail safely. As the SIL increases, the safety level of the product increases. Therefore, the probability that the system will fail to perform decreases.

Often used in the processing industry, SIL offers complex safety regulations to ensure the avoidance of catastrophic accidents and errors that can be damaging to the most stringent operations.

QUINT 20+ power supply introduces a single device with a protective lacquer coating that features ATEX, IECEx and Class I, Division 2 approvals, which allows the power supply to be mounted within potentially explosive areas (Zone 2).

The plus version integrates a decoupling MOSFET for 1+1- and n+1-. In this variant, built-in redundancy provides symmetrical load distribution and increases system availability.

The functional safety approval allows the QUINT 20+ power supply to be used in applications up to SIL 3, according to IEC 61508. The safety function is to limit the output voltage to 30Vdc, and if higher, to switch off within 20 milliseconds. The safe state is no output voltage. Phoenix Contact designed the power supply with double over-voltage circuitry, it also has a Hardware Fault Tolerance (HFT) of 1.

Advantages of QUINT Power Supplies

  • SFB Technology selectively trips standard miniature circuit breakers; consumers connected in parallel continue working
  • Preventive function monitoring indicates critical operating states before errors occur
  • Easy system extension, thanks to static boost; starting of difficult loads, thanks to dynamic boost
  • High noise immunity, thanks to integrated gas-filled surge arrester and more than 20 ms mains failure buffer time
  • Space savings in the control box, thanks to a narrow, slim-line design
  • Power supplies with maximum functionality are part of the COMPLETE line system