NEMA resistor classes and application table Post Glover

NEMA Resistor Classes and Application Table

The following table is for selecting the NEMA Class for an application in relation to starting torque and duty cycle.

NEMA Classification of Resistors

Approximate percent of full-load current on first point starting at "Rest".	Class numbers applying to duty cycles
	30 sec. on Out of each 15 min.	5 sec. on Out of each 80 sec.	10 sec. on Out of each 80 sec.	15 sec. on Out of each 90 sec.	15 sec. on Out of each 60 sec.	15 sec. on Out of each 45 sec.	15 sec. on Out of each 30 sec.	Continuous Duty
25 50 70 100 150 200 or over	101 102 103 104 105 106	111 112 113 114 115 116	131 132 133 134 135 136	141 142 143 144 145 146	151 152 153 154 155 156	161 162 163 164 165 166	171 172 173 174 175 176	91 92 93 94 95 96

When an armature shunt resistor is added, the class number shall include the suffix "-AS". Example: Class 155-AS is a resistor which includes an armature shunt and which will allow an initial inrush of 150 percent with the armature shunt open. When a dynamic braking resistor is added, the class number shall include the suffix "-DB".

NEMA Resistor Application Standards
APPLICATION	NEMA CLASS				APPLICATION	NEMA CLASS				APPLICATION	NEMA CLASS
Blowers Centrifugal ............................ 133-93 Constant Pressure ................. 135-95 Brick Plants Augers, Conveyors, ..................... 135 Dry Plans, Pug Mills By-product Coke Plants Door Machine, Leveler Ram ........ 153 Pusher Bar, Valve Reversing Machines Cement Mills Conveyors ................................... 135 Crushers ..................................... 145 Elevators ................................... 135 Rotary Dryers ........................ 145-95 Grinders and Pulverizers ........... 135 Kilns ...................................... 135-95 Coal and Ore Bridges Bridge ........................................ 153 Closing, Holding ....................... 162 Trolley ............................ 162 or 163 Coal Mines Car Hauls .................................. 162 Conveyors ..................... 135 or 155 Cutters ..................................... 135 Crushers ................................... 145 Fans ................................ 134 or 95 Hoists - Slope ..................................... 172 - Vertical ................................. 162 Jigs, Picking Tables ................. 135 Rotary Car Dumpers ............... 153 Shaker Screens ....................... 135 Compressors Constant Speed ...................... 135 Varying Speed - Centrifugal ............................. 93 - Plunger Type .......................... 95 Concrete Mixers ................. 135 Cranes-General Purpose Hoist ................................ 153-163 Bridge or Trolley with - Sleeve Bearings ............. 153-163 - Roller Bearings .............. 152-162 Flour Mills Line Shafting ........................... 135					Food Plants Butter Churns, Dough Mixer ............. 135 Hoists Winch ............................................... 153 Mine Slope ...................................... 172 Mine Vertical .................................... 162 Contractor’s Hoists .......................... 152 Larry Cars ...................................... 153 Lift Bridges .................................... 152 Machine Tools Bending Rolls ....................... 163 or 164 Boring Mills ...................................... 135 Bulldozers ....................................... 135 Drills, Gear Cutters .......................... 115 Grinders ........................................... 135 Hobbing Machines, Lathes .............. 115 Milling Machines Presses, Punches ............................. 135 Saws, Shapers ................................. 115 Metal Mining Ball, Rod and Tube Mills .................. 135 Car Dumpers-Rotary ....................... 153 Converters-Copper ......................... 154 Crushers .......................................... 145 Conveyors ........................................ 135 Tilting Furnace ................................. 153 Paper Mills Beaters ............................................. 135 Calenders .................................... 154-92 Chippers .......................................... 145 Pipeworking Cutting and Threading .................... 135 Expanding and Flanging ............ 135-95 Power Plants Clinker Grinders ............................. 135 Coal Crushers ................................. 135 Conveyors - Belt, Screw ................................... 135 Pulverized Fuel Feeders ................. 135 Pulverizers - Ball Type ...................................... 135 - Centrifugal ................................... 134 Stokers ....................................... 135-93 Pumps Centrifugal ................................. 134-93 Plunger ....................................... 135-95					Rubber Mills Banbury, Crackers .......................... 135 Calenders ...................................... 155 Mixing Mills, Washers .................... 135 Steel Mills Accumulators ................................. 153 Casting Machines-Pig, .................. 153 Charging Machines - Bridge .............................. 153 or 163 - Peel ................................. 153 or 163 - Trolley ............................. 153 or 163 Coiling Machines .......................... 135 Converters-Metal .......................... 154 Conveyors .............................. 135-155 Crushers ....................................... 145 Furnace Door, Gas Valves, ........... 155 Gas Washers Hot Metal Mixers ........................... 163 Ingot Buggy, Kickoff, .................... 153 Levelers Manipulator Fingers .......... 153 or 163 Pickling Machine, .......................... 153 Pilars-Slab, Racks Reelers ......................................... 135 Saws-Hot or Cold .......................... 155 Screw Downs ..................... 153 or 163 Shears, Shuffle Bars ..................... 155 Side Guards ....................... 153 or 163 Sizing Rolls, Slab Buggy, .............. 155 Soaking Pit Covers Straighteners ................................ 153 Tables - Approach .................................... 153 - Lift ................................... 153 or 163 - Main Roll ......................... 153 or 163 - Roll ............................................. 153 - Shear Approach .............. 153 or 163 - Transfer...................................... 153 Tilting Furnace ............................. 153 Wire Stranding Machine ............... 153 Woodworking Plants Boring Machines, Lathe, ............... 115 Mortiser, Moulder, Planers, Power Trimmer and Mitre, Sanders, Saws, Shapers, Shingle Machine

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