Reliance SSCC Operation11/13/2017The Reliance SSCC card part number 0-51874-2 is the static sequencing and control card. Inputs to the sequencing portion of the SSCC consist of a 110V AC control power reference, start, stop, and jog push buttons, and an aux contact closure from the motor armature loop contactor. Outputs include logic signals which enable the proper major loop reference, sequential logic signals to control the major and minor loop standby switches, and relay contacts to control the M contactor. The SSCC card interfaces directly with logic signals from the OLVC card to provide overload, IET field loss, line loss, incorrect phase sequence, power up sequencing, and controlled stop sequence.With the exception of run relay, the SSCC uses static logic to perform all sequencing functions. The run relay provides a nonelectric means of stopping the drive in the event of a failure in any of the electronic circuits. An M control relay is provided to switch power to the M contactor coil.Push button control signals in the SSCC operate from 110 volt AC power and photo-isolators are used to couple their outputs to the low level logic elements within the card.Pressing the start pushbutton energizes a photocoupler that activates a logic converter. Through the action of this logic converter with the mode and reference selector the SSCC enables the run reference switch on the CRCF card. This will cause the drive to follow the speed setting determined by the operator’s speed control device. Simultaneously, power is obtained through the start button and diode D1 to charge the run relay capacitor. When this capacitor is charged, the run relay closes, provided the run relay switch is a normally closed FET switch which acts to open the run relay under internally generated drive stop commands.The M aux contacts complete the circuit to the appropriate photocoupler and energizes the minor loop and major loop on the CLDK and CRCF cards.Jog sequence operation is the same as described in the start sequence except that the run relay capacitor is charged by a different diode and is activated by a signal from the jog button. In the jog mode the jog reference is used for speed control through the action of the mode in reference selector and the FET jog enable switch on the CRCF card. When the jog button is released the jog reference is opened on the CRCF, the speed reference to the major loop is zero and the run relay switch is opened and initiates the stop sequence. Back To Blog
Reliance SSCC Operation11/13/2017The Reliance SSCC card part number 0-51874-2 is the static sequencing and control card. Inputs to the sequencing portion of the SSCC consist of a 110V AC control power reference, start, stop, and jog push buttons, and an aux contact closure from the motor armature loop contactor. Outputs include logic signals which enable the proper major loop reference, sequential logic signals to control the major and minor loop standby switches, and relay contacts to control the M contactor. The SSCC card interfaces directly with logic signals from the OLVC card to provide overload, IET field loss, line loss, incorrect phase sequence, power up sequencing, and controlled stop sequence.With the exception of run relay, the SSCC uses static logic to perform all sequencing functions. The run relay provides a nonelectric means of stopping the drive in the event of a failure in any of the electronic circuits. An M control relay is provided to switch power to the M contactor coil.Push button control signals in the SSCC operate from 110 volt AC power and photo-isolators are used to couple their outputs to the low level logic elements within the card.Pressing the start pushbutton energizes a photocoupler that activates a logic converter. Through the action of this logic converter with the mode and reference selector the SSCC enables the run reference switch on the CRCF card. This will cause the drive to follow the speed setting determined by the operator’s speed control device. Simultaneously, power is obtained through the start button and diode D1 to charge the run relay capacitor. When this capacitor is charged, the run relay closes, provided the run relay switch is a normally closed FET switch which acts to open the run relay under internally generated drive stop commands.The M aux contacts complete the circuit to the appropriate photocoupler and energizes the minor loop and major loop on the CLDK and CRCF cards.Jog sequence operation is the same as described in the start sequence except that the run relay capacitor is charged by a different diode and is activated by a signal from the jog button. In the jog mode the jog reference is used for speed control through the action of the mode in reference selector and the FET jog enable switch on the CRCF card. When the jog button is released the jog reference is opened on the CRCF, the speed reference to the major loop is zero and the run relay switch is opened and initiates the stop sequence.