Resistor Technical Information and Quote Specifications

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Resistor Technical Information and Quotation Specifications

Following are typical industrial resistor applications and additional information needed by Avtron to quote. (Contact us or use the Price Quotation Request Form.)

Once answers are received an Avtron Sales Engineer can determine the resistor assembly most suitable for your application.

Industrial Resistor Applications	^ Back to Top
A. NEUTRAL GROUNDING RESISTORS Resistor inserted between neutral and ground of a transformer or generator serves to limit fault current to a safe predetermined level.
*Information needed to quote:* System Voltage Line-to-Neutral Voltage Current Rating Maximum Time On Open or Enclosed Current Transformer Ratio (if applicable) Grounding Transformer KVA Rating (if applicable) Special Options	Options include: Current Transformers Potential Transformers Disconnect Switches (oil or air insulated) Overcurrent Relays Aluminum or Stainless Steel Enclosures Special Paint Seismic Qualified Units High Altitude Ratings (above 6000 feet) Hazardous Location Ratings (Class 1, Group D, Division II)
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B. MOTOR CONTROL RESISTORS B.1. Dynamic Braking Resistor for AC or DC Drive. (Electrical ratings are usually specified by drive manufacturer.)	*Information needed to quote:* Ohms Watts Enclosed? If yes, indoor or outdoor?
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B.2. AC Wound Rotor Induction Motor (also referred to as a slip ring motor). Resistor is wired into the motor secondary slip rings and provides a soft start as resistance is removed in steps.	*Information needed to quote:* Application (ex: hoist, bridge, trolley, pump, conveyor, etc.) Motor H.P. Secondary volts and amps (from motor nameplate) Starting torque (if known) Number of speed points (ex: 4 steps of resistance = 5 speeds). NEMA duty class (if known) Enclosed? If yes, indoor or outdoor?
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B.3. AC Squirrel Cage Motor. Resistor is used as a ballast for soft starting (also called a reduced voltage starter).	*Information needed to quote:* Application (ex: hoist, bridge, trolley, pump, conveyor, etc.) Motor H.P. Normal line voltage Full Load Amps (F.L.A. from motor nameplate) Indoor enclosure is standard.
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B.4. DC Series Wound Motor. Current limiting resistor is wired to the field to control motor current (torque) for starting or stopping.	*Information needed to quote:* Application (ex: hoist, bridge, trolley, pump, conveyor, etc.) Motor H.P. Normal line voltage Full Load Amps (F.L.A. from motor nameplate) Starting torque (if known) Number of speed points (ex: 3 steps of resistance = 4 speeds). For Dynamic Lowering (typically a hoist) - need the name of the control manufacturer. Enclosed? If yes, indoor or outdoor?