PULS YR40.242 12-28V 40A MOSFET Dual Redundancy Module

A low-loss MOSFET module for 1+1 and N+1 24 V redundancy

The PULS YR40.242 is a dual-input redundancy module that replaces the usual decoupling diodes with MOSFETs. According to the datasheet this reduces heat and voltage drop: 72 mV at 2 x 10 A, 140 mV at 2 x 20 A, and only 1.7 W loss at 20 A or 5.9 W at 40 A output. That is why the module is only 36 mm wide with a rugged metal housing. It is intended for N+1 and 1+1 redundant systems and is suitable for all DIMENSION power supplies except the QT20 and QTD20 series.

The datasheet also mentions the YR40.241, which has an additional circuit that generates a supply voltage for the internal MOSFETs even when the output is in short circuit, making it suitable for any power supply. The YR40.242 does not need an auxiliary voltage.

Technical specification

MOSFET versus diode redundancy

A diode module loses about 0.6 to 0.9 V at rated current, which is 3 to 4 % of a 24 V rail and turns into heat; at 40 A that would be about 24 W or more (derived). The YR40.242 drops 140 mV at 2 x 20 A and 5.9 W at 40 A, so the 36 mm housing runs much cooler. The saving matters in panels where space is tight and ambient temperature is high. Compared with the MLY10.241 on this site, the YR40.242 handles four times the input current per channel (20 A against 5 A) but is limited to 12-28 V systems.

Sizing and installation notes

• Each input is rated 20 A continuous, so a strict 1+1 design carries up to 20 A of load on one supply; with two 20 A supplies sharing a 40 A load the module forms an N+1 group.
• Typical partners: QS20.241 (see this site), CP20 and other DIMENSION units with up to 20 A output.
• Use two supplies of one type, adjusted to the same output voltage.
• Output has no over-current protection; add fuses or circuit breakers downstream.
• Brackets in the order list: ZM2.WALL for wall or panel mounting and ZM11.SIDE for side mounting.

GCC use cases

Redundant 24 V supplies are specified for compressor control, burner management, water utility SCADA cabinets and telecom shelters, where a failing supply must not trip the process. The -40 to +70 C range and low heat loss make the YR40.242 a good match for sun-heated enclosures. See the Power Modules category.

Selection and installation notes

A redundancy or buffer module is selected from the load current, the output voltage and the way the supplies are arranged. Size each supply so one can carry the whole load, keep the wiring from each supply equal in length and cross-section, check the polarity and the module rating against the maximum load and test the changeover by switching one supply off. Allow the heat dissipation and the clearances on the data sheet.

Information needed for a quotation

Send the full model code, the quantity, the delivery location in Oman or the GCC, the intended use and any accessories needed, so that the complete package can be quoted together.

Documents and supply information

The manufacturer data sheet is attached to this page and should be read together with the project specification and the site risk assessment before a purchase is confirmed. Ratings, standards and dimensions are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.

Related PULS products: PULS MLY10.241 12-48V 10A Dual Diode Redundancy Module, PULS UF20.241 24V 20A Capacitor Buffer Module 200 ms, PULS QT40.241 24V 40A 960W Three-Phase DIN Rail Power Supply, PULS CS10.241 24V 10A 240W Auto-Select DIN Rail Power Supply, PULS CP10.241 24V 10A 240W Single-Phase DIN Rail Power Supply and PULS QS20.241 24V 20A 480W Single-Phase DIN Rail Power Supply.