MULTIPLE FAN MOTORS ON ONE CONTACTOR
MULTIPLE FAN MOTORS ON ONE CONTACTOR
(OP)
I HAVE A WAREHOUSE PROJECT WITH 20-5HP, 480V VENT FANS. SHORT OF BUYING 20 STARTERS, CAN I USE ONE STARTER FOR 5 FANS AND ROUTE A COMMON FEEDER TO A POWER DISTRIBUTION BOX WITH FUSE BLOCKS/TIME DELAY FUSES FOR EACH MOTOR ? COST IS A FACTOR FOR THIS INSTALLATION. LOOKING FOR IDEAS.





RE: MULTIPLE FAN MOTORS ON ONE CONTACTOR
I certainly wouldn't recommend it.
RE: MULTIPLE FAN MOTORS ON ONE CONTACTOR
Five 5 HP. fans started together will usually have a greater starting current then one 25 HP. motor.
You may want to size the feeders at 125% of the total load rather than the sum of the currents plus 25% of the largest motor.
Does anyone know the NEC requirement for feeders for simultaneously starting motors?
respectfully
RE: MULTIPLE FAN MOTORS ON ONE CONTACTOR
RE: MULTIPLE FAN MOTORS ON ONE CONTACTOR
RE: MULTIPLE FAN MOTORS ON ONE CONTACTOR
A better method is to use devices that are very common in IEC countries called Motor Protective Switches (or any one of a dozen similar names). The are often sold in the US as Manual Motor Starters but they provide more functionality than a typical NEMA MMS. All of the big IEC suppliers offer them, and most are now UL listed for what is called "Group Fusing" applications. Each device would be on one motor circuit and provide the Short Circuit Protective Device (SCPD, replacing the fuses), Overload (OL) and Disconnect for each individual motor. They are much easier to mount and wire than all those fuse blocks and OL relays and provide you with a simple way to isolate motors that are down for maintenance while still running the others on that group.
http:/www.jraef.com
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