You have many electrical requirements to meet when specifying panel boards, but is addressing the cost-effectiveness issue ever one of them? In facilities having indoor or outdoor areas with hazardous locations, there is a need for very substantial equipment, namely explosion-proof panel boards. While all industrial facilities require some means to safely provide incoming power to its electrical loads, accounting for all the costs of a panel board is key. Simply providing a distribution means to meet the immediate electrical needs is not enough; there must also be the forethought of installation, access and maintenance costs to maximize the cost effectiveness of the purchase. Installing a cost-effective panel board in a hazardous location begins with the specification of the equipment to meet all these needs.
There can be many hidden costs in the installation process of a panel board. Look for panels to be factory-sealed for the given area. If they are not, there could be the added cost of pouring explosion-proof seals at the site. A fully wired terminal housing including ground bar and solid neutral is a must. This feature makes for easy installation because the circuit breaker housing need not be opened for field wiring, thereby saving time and extra material costs. By design, panels can accommodate a large supply of conductors for ease of installation, again saving time and material costs. This excess wiring prevents one from having to pull additional wires to account for the ever-changing electrical requirements. The panel should also allow for the easy addition or change of breakers and operators. Also, make sure the location of the conduit is known for the incoming power to enter the terminal enclosure. A good panel board design will accommodate both the top and bottom sides for incoming power. Lastly, the panel chosen should include a lifting bracket as standard equipment.
When accessing a panel, you need to account for the time necessary to obtain the required approvals (e.g., safety engineers, electricians, maintenance personnel, etc.) and to physically open the panel. Cover bolts that are quick release, spring loaded and captive provide labor-saving, fast access to the enclosures and fast indication of bolt release from body threads. They also prevent the loss of bolts when accessing the panel respectively. Saving labor throughout the panel board’s life, a self-aligning circuit breaker operator eliminates reopening of the enclosure to align operator mechanisms with breaker toggle handles.
For decreased maintenance costs, there are many features to consider in addition to self-aligning branch circuit operators, factory-sealing and cleverly designed cover bolts. For instance, designing with the proper materials is a must. For enclosures, copper-free aluminum is essential as a standard material against corrosion. Similarly, stainless-steel hardware and O-rings answer corrosion concerns for harsh environments. In areas with high humidity and/or temperature cycles, breathers and drains provide a superior defense. A NEMA 4-rated neoprene gasket design ensures water tightness and reduces replacement costs and equipment downtime by providing hose-down integrity. Other standard features to look for are removable mounting feet and hinges.
The proper design will account for possible damage to these features that could render a panel useless if maintenance cannot be performed on repairing these design features. Lighting panels with either Ground Fault Interruption for personnel protection or Electrical Protection Devices for heat tracing applications must have an easy push-to-test system that will promote the recommended monthly testing schedule. A routine maintenance program will ensure the reliability of the protective device performance. Looking to cover the future needs, a panel board should have future entries drilled, tapped and plugged, be wired for a maximum number of circuits and amperage and adaptable to adding or removing breakers and operators.
In summary, installing panel boards cost-effectively in hazardous locations begins with the specification of the equipment. The proper panel board choice will account for installation, access and maintenance costs to maximize the cost effectiveness of the purchase. The catalog numbering and wiring systems should be easy to specify, order and price, thereby eliminating possible errors. Look for a Group B (Hydrogen, Methyl Tertiary Butyl Ether (MTBE), etc.) rating, which will allow flexibility in case an area is reclassified in the future. Lastly, make sure that third-party certifications are available to meet or exceed the inspection authority requirements for your project. When addressing these issues in the specifying phase of any panel board project for a hazardous location, make sure to consider the above-mentioned items to maximize your purchasing power. EC
O’NEILL is product line manager at Crouse-Hinds Co. He can be reached at mike.o’firstname.lastname@example.org.