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Q.I am planning to install new lighting in a warehouse. Are there any advantages, either in installation costs or in operating costs, to installing 240-volt lighting fixtures instead of 120-volt?

A.Master electrician Sean Kenney responds: Since you can install twice as many lights on a 20-amp 240-volt circuit as on a 20-amp 120-volt circuit, installation costs for 240-volt lighting should be lower. If your building is large, the savings in labor and materials could be substantial. Another benefit to 240-volt lighting is that the load is automatically balanced; there is no need to balance each 120-volt leg, as there is with 120-volt lighting.

One drawback to using 240-volt equipment is the limited availability of replacement ballasts. If you plan to use HID (high-intensity discharge) lighting, this is not a concern, since most HID lights have multi-tap ballasts. But 240-volt fluorescent ballasts are not widely available and would have to be obtained at an electrical supply house.