Variable Frequency Drive Design Guidelines

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1 Variable Frequency Drive Design Guidelines The Variable Frequency Drive Design Standard provides design criteria and specifications used in the procurement and application of variable frequency drives (VFDs). Table of Contents 1. Summary 2. Contacts 3. Selection & Design 4. Installation 5. Documentation and Parameter Backup 6. Safety 7. Calibration & Testing 8. Identification 9. Revision Tracking 1. Summary Consider all guidance in this document mandatory unless otherwise identified as optional or preferred. Any variance from GMI requirements or preferences requires prior GMI Engineering approval. Obtain approval from the engineer that issued this document or has been designated as responsible for project deliverables. GMI will provide and document specific project requirements and approvals. 2. Contacts Daniel Migliori Senior Controls Engineer (763) (Owner) Mark Chatterton Sr. Principal Engineer (763) (Backup) 1

2 3. Selection & Design 3.1 General Use the following Allen-Bradley PowerFlex Drives. Drive Control Configuration Horsepower Range Notes PowerFlex 525 Non-network solutions only 1 20 Hp Required: Line Reactors Safe-Torque-Off PowerFlex 525 EtherNet/IP 1 20 Hp Required: Line Reactors Safe-Torque-Off PowerFlex 753 Ethernet/IP Hp Safe-Torque-Off PowerFlex 755 EtherNet/IP 350+ Hp Safe-Torque-Off For normal duty, design for operating frequencies between 30Hz and 90Hz. Verify and validate that the reducer/reduction gear sizes comply with the designed operating frequencies. For normal duty, design the VFD voltage level at 480 Volt, 3 Phase, 60 Hertz. (In Canada, 600 Volt, 3 Phase, 60 Hertz.) Use only UL listed VFDs (CSA in Canada). Install VFDs inside an enclosure unless they have been specifically designed by the manufacturer for field mounting. Enclosure-mounted VFDs can be selected with IP20 or NEMA Type 1 housing ratings. Match the drive size to the motor size for normal duty, with the minimum VFD sized for a 1 HP motor. For heavy or severe duty, size the drive to one size larger than the motor to allow for constant torque and higher peak amp requirements. Use similar sized drives throughout a system, if possible. Each drive must have a full-featured keypad and display (HIM Module). 2

3 GMI discourages the use of DC motors. GMI discourages the uses of mechanical variable speed drives. Refer to CIS_301_Electric_Motor_Design_Guidelines. 3.2 Communications and Controls Make sure the VFD is capable of one of the communication protocols listed below. The controls engineer determines the protocol choice based on the infrastructure at the VFD s location. Make sure that communications to and from the drive include all start and stop commands, speed control and setpoints, and diagnostics. EtherNet IP Limit the number of nodes to 40 for each segment. Use the manufacturer s EtherNet/IP Performance and Application Guidelines. ControlNet Use for legacy systems only. Limit the number of nodes to 20 for each segment. Use Quad Shield coax (Belden 3092A) cable for ControlNet applications. DeviceNet Use for legacy systems only. Limit the number of nodes to 35. Refer to the manufacturer s recommendations to determine the proper configuration. AB-RIO Use for legacy systems only. Plan for integration of VFD controls with the human machine interface (HMI) including operations status displays on the HMI, fault handling routines, and troubleshooting features. GMI will provide HMI templates with diagnostics, alarms, and status indications during process design. 4. Installation Follow all manufacturer recommendations and requirements for mounting and installing VFDs. Additional requirements and guidelines include: Install VFDs in an enclosure unless they have been specifically designed by the manufacturer for field mounting. Do not install more than three motor power feeds in the same conduit. Ground the VFDs according to manufacturer s recommendations. 3

4 Use shielded cable (Belden 295XX where XX is related to wire gauge from the VFD to the load). Keep cable lengths shorter than 100 feet. If the application includes a distance greater than 100 feet, follow the manufacturer s recommendations. Power line reactors shall be installed on the line side of the PowerFlex 525 drive and all other drives which do not have built-in reactors or DC input chokes. Supply VFDs with an Allen-Bradley 140M Self-Protecting Motor Starter (per manufacturer s recommendations and sizing tables) or Bussmann Optima (OPM- 1038RSWC) fused primary protection (short circuit protection). GMI prefers the Allen-Bradley 140M Self-Protecting Motor Starters. Do NOT use a contactor on the line side of the VFD. Use load-side contactors for safety (if the A-B Safe-Off-Module is not available). Refer to the VFD manufacturer s documentation for additional safety recommendations. (See Figure 1.) Install a local motor disconnect switch on all motors. Make each local motor disconnect switch lockable and suitable as a safety device in compliance with GMI s lockout tagout (LOTO) program. Furnish the local disconnect with an auxiliary contact wired to a PLC input. The preferred disconnect switch is either a Hubbell HBLDS#AC (where # is 3 [30A], 6 [60A], or 10 [100A]) or an Allen- Bradley 194E-CAxxE-P11 (where xx is related to the load size). 4

5 Figure 1, Drawing Template for PowerFlex 525 w/ Safe-Off-Module 5

6 5. Documentation and Parameter Backup GMI requires that all VFDs have Electrical Schematics (Figure 1, Drawing Template for PowerFlex 525 With Safe-Off-Module) which contain a parameter table that lists the motor specifications as well as all parameter changes from the factory default settings (Figure 2, VFD Parameter Table). AutoCAD drawing templates are available from GMI engineering. GMI requires that all VFDs have an electronic backup of the drives parameters. Back up parameters with Connected Component Workbench or directly in RSStudio 5000 project. Drive backup files are to be stored in one of the following locations: AutoSave (MASS) using Universal Plug-in (preferred location) On the MASS server (xxxmass1\d:\autosave\drives) Another server share The following table is an example of a parameter table with changes from default (not all inclusive). Parameter # Name Value Default Units 31 MOTOR NP VOLTS X VAC 32 MOTOR NP HERTZ X 60 HZ 33 MOTOR OL CURRENT X AMP 34 MOTOR NP FLA X 0.0 AMP 35 MOTOR NP POLES 4 4 POLES 36 MOTOR NP RPM RPM 37 MOTOR NP POWER X KW 41 ACCEL TIME 1 X SECS 42 DECEL TIME 1 X SECS 43 MININUM FREQ X 0 HZ 44 MAXIMUM FREQ 60 0 HZ 6

7 45 STOP MODE 5 0 RAMP 46 START SOURCE KEYPAD 47 SPEED REFFERENCE DRIVE POT 53 RESET TO DEFAULTS DIGITAL INPUT 2 NOT USED 48 2 WIRE FWD 63 DIGITAL INPUT 3 NOT USED 50-2 WIRE REV 65 DIGITAL INPUT 5 NOT USED 7-PRESET FREQ 66 DIGITAL INPUT 6 NOT USED 7-PRESET FREQ 67 DIGITAL INPUT 7 NOT USED 5- SPD + STRT2 68 DIGITAL INPUT 8 NOT USED 9- JOG FWD Figure 2, VFD Parameter Table (PowerFlex 525) 6. Safety Refer to GMI templates and typical examples of the safety circuits to meet the requirements of a NFPA 79 Category 0 Stop (immediate removal of power to the motor) or Category 1 stop (controlled stop, then removal of power to the motor). Remove power by electromechanical components (NFPA-79). The PowerFlex Safe-Off Module, when used with suitable safety components, provides protection according to ISO PL-d for safe off and protection against restart. The PowerFlex Safe-Off- Module is just one safety control system. All components in the system must be chosen and applied correctly, to achieve the desired level of operator safeguarding. Resetting of any safety circuit must not permit the automatic restart of any machine. A second action separate from the safety system is required to start the machine. Refer to the VFD manufacturer s documentation for additional safety considerations. The drawing (Figure 3) provides an example of a typical safety circuit installation suitable to be used in a PL d safety circuit with a NFPA 79 Stop category 0 or 1. 7

8 Figure 3, VFD Safety w/ Contactors or Safe-Off-Module 7. Calibration & Testing Demonstrate full range of speed (such as 30 90Hz) to validate proper reducer sizing. 8. Identification Label all motors at a permanent location near, but not on, the motor or gear reducer. Make sure the label contains the motor tag number (refer to the equipment tagging guidelines), the common name (such as PRODUCT PUMP 3), and starter location. Label cabinets or enclosures that house contactors, starters, or other control devices on the outside with the source of the electrical power used. This might be the number of a specific MCC or a breaker number from a lighting distribution panel or general utility power panel. Label all major components (such as VFD, motor starters or local disconnects) as identified on the schematic diagrams. Identify all wires at each termination. Use wire markers to identify a unique number that corresponds to the schematic diagram. When the wires are part of a PLC system, label them with the same number as the input or output points of the PLC. 8

9 9. Revision Tracking Revision Number Revision Date Revision Owner Revision Summary (Brief description of major changes) 0 5/11/2005 Daniel Migliori Original development 1 3/1/2018 Daniel Migliori Reformatted and renumbered the document (was CIS_302). Updated drawing templates. Added drive documentation and Backup procedures. 9

For normal duty, design the VFD voltage level at 480 Volt, 3 Phase, 60 Hertz. (In Canada, 600 Volt, 3 Phase, 60 Hertz.)

For normal duty, design the VFD voltage level at 480 Volt, 3 Phase, 60 Hertz. (In Canada, 600 Volt, 3 Phase, 60 Hertz.) Introduction The Variable Frequency Drive Design Guidelines provides design criteria and specifications used in the procurement and application of variable frequency drives (VFDs). Table of Contents 1.