Hoist Panel and Wiring for Hazardous Area
Picture shows two explosion proof crane panels designed, manufactured and wired on the overhead crane for Class II area. These panels are capable of operating the hoist & trolley motors in forward & reverse direction. The trolley & hoist motors are also equipped with a 230V brakes which are powered up from the control panel.
Panel has a manual and auto selector switch. In manual panel is operable from a hard-wired pendant and in auto panel is operable with wireless radio. Wireless radio is factory approved for hazardous area but the pendent, over weight limit-switch, lower & upper limit switches are rated for general purpose area only. To save cost on devices and to avoid inconvenience of sourcing & wiring explosion proof devices we designed the circuit in such a way that we were able to use all the general purpose rated devices on the crane by wiring them through intrinsically safe barriers. We were able to use non classified, lighter, less bulky and cheaper devices on the crane, saving customer money and extra hassle.
The original specification was asking for an explosion proof pendant but with our intrinsically barrier design we used a general purpose pendent. Customer really liked the non-classified pendent for this crane and it was only possible by feeding through IS barriers.