Better Power in Smaller Packages: Building Space Reduction into Control Panel Design
January 2019 | By Brian Schmalberger
Brian Schmalberger is an OEM segment market leader for ABB.
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With all the many advances in control system design – from smart components to advanced power protection and new levels of energy efficiency – the ongoing challenge of putting more power control in less space remains at the top of every control panel engineer and designer’s priority list.
Minimizing the physical dimensions of control and electrical panels gives designers the flexibility to accommodate complete systems in tight or restricted areas. Additionally, equipment manufacturers serving markets from HVAC to pumps and industrial automation look to deploy compact power control panel to reduce costs and free up valuable real estate for expanded system features and functions.
Small is a Big Thing in Power Control Panel Design
Reducing the overall footprint of control panels and protection devices starts with a re-evaluation of every component of a power system, from circuit breakers to contactors and starters, to pushbuttons and e-stops.
A new generation of globally-rated, compact AC/DC contactors, for example, use a permanent magnet design achieve a full 10 percent reduction in depth, as well as a 22 percent width reduction. Add the capability to supply either top or bottom-feed power, and control panel designers can reduce the vertical dimensions of a panel by as much as 10 percent.
In another trend, the use of miniature circuit breakers (MCB) in control panel designs reduces the size of the protection devices required. For example, our ElfaPlus* MCB can replace larger, more expensive molded case circuit breakers up to 40A (at 480/277Vac). This increased amp rating can be used in motor applications up to 25hP. Additionally, many MCBs are also designed to be mounted on smaller, 35 mm DIN rails to further reduce overall size requirements while eliminating the need for bolted wire space and specialized tools.
Sometimes space reduction is a byproduct of other design requirements. One goal for the design of MCBs is to withstand extreme temperatures that arise in many industrial settings. By using high-performance materials and alloys, new MCBs generate less heat, which is ideal for harsh settings and can reduce the size of panel enclosures by up to 25 percent.
The move toward modular, more configurable power panels, including our EntellEon*, is also contributing to a reduction in panel size and increased capacity. New power panel interiors can accommodate mixed size and mixed rated circuit breakers in the same row, eliminating wasted space and increasing overall current density.
Consolidating Function to Reduce Size and Increase Real Estate
In the drive to reduce the size of electrical and control panels, many new control and power devices are consolidating into single units multiple functions and capabilities previously performed by separate components.
For example, recent advances in modular contactor design, such as our Efficor line, allows contactors to be combined with motor starters and auxiliary components, such as relays and timers in one module. This eliminates the need for a second DIN rail. These advances in integration reduce overall space requirements, while also greatly simplifying the need for additional installation parts, wiring and labor.
Newer soft starter components, including our family of ASTAT soft starters, now have integrated by-pass technology, eliminating the cost and size of a dedicated contactor, along with the added benefit of generating less heat. Advanced circuit trip units can also incorporate current sensing capabilities, eliminating the space and cost of separate current transformers in the system.
Building new functionality into existing platforms, such as incorporating arc flash protection capabilities into low voltage molded case circuit breakers (MCCB), also reduces the size of power components while boosting the value and function of these units. Our new line of GuardEon* MCCB’s, for example, employ selective coordination and arc flash protection technologies as core functions of electronic trips units. The trip units can also be adjusted on the unit, eliminating the need for ratings plugs altogether. This reduces the numbers of standardized stocking units (SKUs) to keep on hand and makes adjustments in the field much simpler and faster.
Lifecycle “Size” Reduction – Ordering and Inventory
We often think of space reduction in terms of the overall number of components in the design or size of the enclosure. Yet a lifecycle view of space reduction also includes initial ordering and inventory. Many companies now provide more standardized product platforms, reducing the large number of parts, or SKUs, that a panel builder needs to specify and stock. Take, for example, the use of a single standardized trip unit for multiple MCCBs at different ratings. Instead of stocking four SKUs (two MCCBs per rating plus two trip units) they can stock just three (two MCCBs with a single standardized trip unit). Eliminating that one SKU on an average inventory of 200 units per year at an average unit cost of $425, adds up to a cost savings of $19,250 a year.
When designing control panels for any industrial or commercial setting, space is always a premium – either to reduce the size or footprint of a device, to recapture design real estate to increase function or capacity, or to reduce inventory costs. Looking at power control and protection components and platforms that give back valuable space is now a key part of the tool kit for designers and manufacturers.