Solution to Circumvent Voltage Drop in DC Power Cables

Power Engineers designing DC power systems for critical loads will include various backup power sources for best uptime reliability, generally incorporating lead-acid and lithium batteries. When the primary power source fails (AC mains, solar, generator), the batteries will discharge to support the DC loads. As the batteries release their stored capacity, the DC voltage is dropping, and an inverse increase in electrical current occurs. Electrical Engineers, in turn, specify large cables to suit the worst-case (highest) electrical currents. There is no argument this has been the correct system design method, as it follows mandated electrical safety standards, but the cost of sourcing and deploying large DC cabling weighs heavily.

Sites with long cable runs to devices across the facility, and/or where cabling extends up towers to equipment such as Remote Radio Units (RRU), have a snowball effect of the voltage drop problem. Effectively the longer a cable run is, the higher the voltage drop and the larger the cable needs to be to deliver a suitable voltage to the equipment. Cable sizes typically are not a contested topic and when you asked an Electrical Engineer for a better solution in the past, you could expect to be told ‘it is what it is’.

Eaton’s Solution

The MCU-ES Energy Saver DC-DC Converter is a cutting-edge DC to DC converter designed for voltage regulation, to improve electrical isolation and surge protection of critical telecommunications, electrical utility, and industrial site equipment.

Industry Leading Power Density

The Eaton MCU-ES delivers 2kW of power in a high-density power module. Its compact size and short depth make it ideal for limited-space applications such as macro base station buildings and outdoor cabinets. The MCU-ES is a hot swappable plug-and-go module that can be utilised with a range of Eaton power chassis to match the application, supported by the Eaton SC300 system controller.

Efficiency Matters

Operating at peak efficiency of over 96% over a wide range (30–100% load), the MCU-ES minimizes waste energy. Whether powering 5G/LTE RRUs or providing a specific voltage during battery discharge to electrically sensitive equipment, this converter delivers. Being fully compatible with existing current generation Eaton DC power systems makes integration seamless.

Robust Performance

An operating temperature rating up to 70°C, a wide DC input voltage range, and a fully user-settable output voltage ensure high reliability even in challenging conditions. The variable-speed fan keeps cooling efficient and quiet.

The Eaton MCU-ES Energy Saver DC-DC Converter finds applications in various critical DC power systems where efficient voltage conversion and regulation are critical, such as:

Communications base stations, where the MCU-ES efficiently powers the RRUs with specific voltage even during battery discharge/recharge, reducing cable size/weight on the power, as well as providing galvanic isolation to communications equipment in the outdoor cabinet or Macro Base Station building.

Data Centres, where a centralised DC power system requires long DC cable runs to DC distribution/equipment, in which cable sizes can be significantly reduced due to the ability of facility engineers to control output voltage to the loads.

Industrial Automation and Power Utility plants, where equipment often requires precise voltage regulation. The MCU-ES can power sensors, actuators, and control systems. The robust performance in harsh environments delivers high reliability where it is required the most.

For further information please contact your local Eaton sales office, Eaton partner or refer to www.eaton.com/au/dc

Written by Chris Barson, Product Manager Power Quality/DC Power Solutions

Top image credit: iStock.com/Rawf8