Emerson UPS Promises Continuous Power for Critical Loads

Emerson has released the D series extension to its SolaHD family of industrial rack-mount, on-line uninterruptible power supplies. The S4K2UD series replaces the current C series and offers an upgraded user interface (UI) and other key design improvements to enhance reliability and power availability.  

The SolaHD S4K2UD is an on-line UPS offering zero switching time between external and internal battery power sources to ensure power continuity to critical loads during loss or disruption to utility power.

The model is available in 120 V and 240 V variants and can support power levels up to 3000 VA. The rack or tower mountable supplies are housed in an industry-standard, low-profile 2U enclosure.  

SolaHD S4K2UD on-line UPS. Images used courtesy of  Canva and Emerson

On-Line Uninterruptible Power Supply

The SolaHD S4K2UD is a UPS designed to ensure power continuity to critical loads, such as servers, networking, and telecommunication hardware, during a disruption or loss of external utility power due to blackouts, brownouts, sags, surges, or noise interference. 

An on-line design means the supply receives and delivers utility power during normal operation, as opposed to standby systems, which are connected only during a power loss event. An on-line UPS can transfer power from the main (utility) to a backup power source (batteries) with essentially no delay, minimizing impacts to critical and potentially sensitive downstream loads.    

Under normal operation, the S4K2UD receives input line power at 120 VAC or 230 VAC (S4K2U30005-D variant), 50/60 Hz and outputs a single-phase, user-configurable 100, 110, 115, 120 or 125 VAC regulated to ±3% (200, 220, 230 or 240 VAC for the S4K2U30005-D). 

When utility line power is interrupted, integrated valve-regulated, non-spillable lead-acid batteries supply the output through a pulse-width modulated inverter to reduce output voltage distortion. The battery has a 9.0 Ah rating that can deliver a full rated load (3,000 VA) for 4 minutes or a 50% rated load for 12 minutes. 

After a full discharge and when reconnected to line power, the internal batteries can recharge to 90% capacity in three hours while the UPS still delivers its full-rated output. The onboard batteries are hot-swappable and can be replaced while the UPS operates. 

Compared with the prior Series C models, the new S4K2UD has a higher output power factor of 1.0 to improve availability and allow for the connection of more loads. The 3,000 VA-rated variant of the 2U low profile (3.5”) module is contained in a 21.3” x 16.9” x 3.5” full metal enclosure and can be rack or stand-alone tower mounted.

Upgraded User Interface  

The S4K2UD is designed to provide status and diagnostic updates, such as battery health status and replacement date predictions. It uses a full-color graphic LCD display, so an external laptop is unnecessary.

S4K2UD user interface with LCD display. Image used courtesy of Emerson

According to Kyle McLeod, Product Marketing Manager UPS for SolaHD at Emerson Discrete Automation, the user interface and advanced diagnostics will significantly improve the customer experience and positively impact maintenance schedules and overall operations.