High-voltage DC input power supplies meet new UL and IEC Regs

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DIN-rail power supply manufacturer PULS UK is launching two QS10 models designed to meet tough new UL and IEC regulations which will affect the input fusing of DC input circuitry.

Until now, many have used AC products in high-voltage DC circuits, particularly with 110V DC battery systems. The new regulations require fusing on both the positive and the negative input (AC power supplies generally have fusing on the live only) and that these are DC, not AC fuses. This does not affect higher voltages (220V DC) but some manufacturers’ data sheets still specify power supplies for lower input DC applications without explaining that this cancels the UL and IEC approval. Under the new legislation, with 110V DC systems, all input fuses will have to be approved for DC applications.

Both the new QS10 units have high-quality UL and IEC-approved DC input fuses included as standard, making the approval of systems, including those using multiple units, straightforward.

PULS UK’s Managing Director Harry Moore says: “Safety is a high priority at PULS and that’s the reason why we’ve taken a proactive approach by updating our QS 10 units ahead of time. Engineers designing control systems today that use high-voltage DC can now incorporate our products knowing they will be safe and comply with next year’s legislation.”

The QS10.241 – D1 delivers an AC input of 100–240V or DC 110–300V and an output of 24V, 10A while the QS10.481-D1 gives an AC input of 100–240V or DC 110–300V and an output of 48V, 5A.

For further information about the new QS10 models from PULS UK, visit the website at

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