Many facilities have rooftop exhaust fans that require service, sometimes at the most inconvenient time. Before service work can be initiated, the NFPA 70E Standard for Electrical Safety in the Workplace requires the establishment of an electrically safe work condition at the fan, including properly interrupting the load current, visually verifying that all blades of the disconnecting device are open, and correctly applying lockout/tagout devices. This may require an arc flash-trained electrician to perform the electrical deenergization work, as well as voltage testing. Since voltage testing potentially exposes workers to live parts, NFPA 70E requires workers to wear appropriate PPE.
Scientific Protein Laboratories (SPL), a global supplier of high quality active pharmaceutical ingredients, took a different approach. SPL recently installed Meltric Decontactor™ Series switch rated plugs and receptacles on rooftop exhaust fans. Decontactors eliminate the need for costly, hard to locate disconnect switches. They also simplify NFPA 70E code compliance for the laboratory because Decontactors help maintain a NFPA 70E defined hazard risk category of zero during the equipment changeout process.
Decontactors can be used to connect power to the exhaust fan. With the Decontactors installed, a technician can safely disconnect, repair or replace, and then reconnect exhaust fan motors with plug-and-play simplicity. There is no need to climb up and down ladders to turn off remote disconnect switches nor is there a need to wear cumbersome PPE when verifying deenergization with a voltmeter because the disconnected plug and receptacle give visual proof.
Decontactors are a combination plug, receptacle, and UL-approved disconnect switch in the same device. An integral switching mechanism ensures the safe make or break of live connections and makes certain that the contacts are dead before the plug can be removed. Once the plug is withdrawn, users are protected from unintentional access to live parts by the receptacle''s safety shutter. Safety is also maintained when reinserting the plug into the receptacle because the male contacts do not engage the live female contacts until after they are fully enclosed inside the device''s arc chambers, thus preventing outside exposure to arc flash -- even in overload conditions.
"With the Meltric connector installed there is no need to physically mount a disconnect within sight for smaller motors on the roof so this is a good solution for us," said Monique Newell, a maintenance specialist at SPL.