Baldor BC142 Installation And Operation Manual

Also see for BC141: Installation & operating manual

Baldor BC142 Installation And Operation Manual Manual pdf 8 page image

3 INTRODUCTIONThank you for purchasing the BC141, BC142, or BC142-6 full-wave variable speed DC motor control, now withSMT construction. The control offers the user the ultimate in reliability and performance at an affordable price. Thecontrols contain a unique patented super-fast Direct-Fed™ current limit circuit that protects the SCR powerbridge against direct shorts1. The reliability of the control is further enhanced with the use of high-surge, 25 AmpSCRs, and AC line and armature fusing2, 3. The control is designed with exclusive Plug-In HorsepowerResistor® 3, which eliminates the need for recalibrating IR Comp and Current Limit when the control is used onvarious horsepower motors. In addition, the rating of the control can be extended to 1.5 HP for controls with 90Volt DC output and 3 HP for controls with 180 Volt DC output, by the use of an Auxiliary Heat Sink4. Catalog Nos.BC142 and BC142-6 also allow operation of 90 Volt DC motors when used on 208/230 Volt AC line input 5.The versatility of the control is confirmed by its extensive list of standard features, such as: selectable armatureand tach feedback and adjustment trimpots for minimum speed, maximum speed, IR compensation, and linearacceleration and deceleration. The control includes Auto-Inhibit®, which eliminates surging during rapid AC lineswitching; pulse transformer triggering, which provides cogless operation at low speed; and superior noise rejec-tion circuitry, which eliminates false starts and blown SCRs. Enable (normally closed) and Inhibit (normally open)functions provide electronic switching of control output.The output voltage of the control is a linear function of the Main Speed Potentiometer rotation. In addition, thecontrol can be used in a voltage following mode by supplying an isolated analog input signal to Terminals “P2” (+)and “P1” (-). The control is compact in size (only 4.30” X 3.64” X 1.25”) and easily replaces all competitive speedcontrols. The control is supplied with a factory installed 25 Amp AC line fuse and a 5 k Ω Main SpeedPotentiometer and QD terminals. All models are UL Listed (USA and Canada) and CE Approved.Notes: 1. Short circuit protected at motor only. 2. Baldor Limited Warranty applies. See page 32. 3. Plug-InHorsepower Resistor® and Armature Fuse Kit supplied separately. See Sections 8 and 9, on pages20 - 22. 4. Catalog No. BC143. See Section 14.1, on page 30. 5. Step-Down operation.7