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. Introduction 2. Design 3. Installation 4. Documentation and Deliverables 5. Products or Material 6. Safety 7. Calibrations and Testing 8. Identification 9. Summaries 1. Introduction Consider all standards described 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. Design Use the following general design guidelines. For normal duty, design for operating frequencies between 30Hz and 90Hz. Verify and validate that the reducer/reduction gear sizes complies 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 a control cabinet, and rate them for IP20, NEMA Type 1 panel mounting. CIS_302_Variable_Frequency_Design_Guidelines_WHQ.doc, 0, October 2005 1
Design 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 overload protection. If possible, use similar sized drives throughout a system. GMI discourages the use of DC motors. GMI discourages the uses of mechanical variable speed drives. Refer to 301_Electric_Motor_Design_Guidelines. 2.1 Communications and Controls Make sure the VFD is capable of the following communication protocols. 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. ControlNet Limit the number of nodes to 20 for each segment. Use Quad Shield coax (Belden 3092A) cable for ControlNet applications. DeviceNet Limit the number of nodes to 35. Refer to the manufacturer s recommendations to determine the proper configuration. EtherNet IP Limit the number of nodes to 20 for each segment. Use the manufacturer s EtherNet/IP Performance and Application Guidelines. 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 trouble shooting features. GMI will provide HMI templates with diagnostics, alarms, and status indications during process design. Fit each VFD with a full-featured keypad if one is offered as an option. CIS_302_Variable_Frequency_Design_Guidelines_WHQ.doc, 0, October 2005 2
Installation 3. Installation Follow all manufacturer recommendations and requirements for mounting and installing VFDs. Additional requirements include: Always mount the VFD in an enclosure. Do not install more than three motor power feeds sharing the same conduit. Ground the VFDs according to manufacturer recommendations. 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. GMI does not require RFI Filters. 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. (See drawings in Safety on page 6 for typical installation.) Do NOT use a contactor on the line side of the VFD. Use load-side contactors for safety (if the A-B safe-off option is not available). Refer to the VFD manufacturer s documentation for additional safety recommendations. (See drawings in Safety on page 6 for typical installation.) 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). CIS_302_Variable_Frequency_Design_Guidelines_WHQ.doc, 0, October 2005 3
Documentation and Deliverables 4. Documentation and Deliverables Refer to GMI s drawing templates for preferred documentation format and expected content. GMI will provide HMI templates with diagnostics, alarms, and status indications during process design. For each VFD furnished with a system, include the final configured parameters, as changed from the default, within the installation wiring drawings. These parameters will be used to re-configure a VFD when required. The following table is an example of parameter table with changes from default (not all inclusive). Parameter # Name Value Default Units 41 MOTOR NP VOLTS 460 460 VAC 42 MOTOR NP FLA 8 8 AMPS 44 MOTOR NP RPM 1750 1750 RPM 45 MOTOR NP POWER 0 0 47 MOTOR OL HERTZ 0 0 HZ 54 MAXIMUM VOLTAGE 460 460 VAC 140 ACCEL TIME 1 10 10 SEC 142 DECEL TIME 1 10 10 SEC 148 CURRENT LMT VAL 12 12 AMPS 158 DC BRAKE LEVEL 0 0 AMPS 201 LANGUAGE ENGLISH NOT SELECTED 276 LOGIC MASK 000010 101111 361 DIGITAL IN1 SEL NOT USED STOP-CF 362 DIGITAL IN2 SEL NOT USED START 363 DIGITAL IN3 SEL ENABLE AUTO/MAN 364 DIGITAL IN4 SEL NOT USED SPEED SEL 1 365 DIGITAL IN5 SEL NOT USED SPEED SEL 2 366 DIGITAL IN6 SEL NOT USED SPEED SEL 3 CIS_302_Variable_Frequency_Design_Guidelines_WHQ.doc, 0, October 2005 4
Products or Material 5. Products or Material Use the following Allen-Bradley PowerFlex Drives. Drive Control Configuration Horsepower Range Notes PowerFlex 4 PowerFlex 40 PowerFlex 70 PowerFlex 700 Non-network solutions only EtherNet/IP DeviceNet ControlNet EtherNet/IP DeviceNet ControlNet EtherNet/IP DeviceNet ControlNet 1 5 Hp 1 15 Hp An additional load side contactor is required for safety 1 50 Hp GMI preferred (safe-off option) 1 200 Hp Typical on Mixer applications (I/O vector options C or D) CIS_302_Variable_Frequency_Design_Guidelines_WHQ.doc, 0, October 2005 5
Safety 6. Safety Refer to GMI templates and typical examples of the safety circuits to meet the requirements of a NFPA Category 0 Stop (immediate removal of power to the motor) or Category 1 stop (controlled stop, then removal of power to the motor). In addition, design E-stops to meet the requirements of EN 954-1:1997; Risk Category 3. Remove power by electromechanical components (NFPA-79). The PowerFlex Safe-Off board, when used with suitable safety components, provides protection according to EN 954-1:1997; Risk Category 3 for safe off and protection against restart. The PowerFlex safe off option 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. Make sure that resetting of any safety circuit device does not initiate any hazardous conditions. Avoid automatic equipment restart when an e-stop button is pulled out or a safety gate is closed. Refer to the VFD manufacturer s documentation for additional safety considerations. The drawings on the following pages provide an example of a typical safety circuit installation. CIS_302_Variable_Frequency_Design_Guidelines_WHQ.doc, 0, October 2005 6
Safety CIS_302_Variable_Frequency_Design_Guidelines_WHQ.doc, 0, October 2005 7
Calibrations and Testing 7. Calibrations and 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 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. CIS_302_Variable_Frequency_Design_Guidelines_WHQ.doc, 0, October 2005 8
Summaries 9. Summaries Enter information in these tables to track revisions to the master document. NOTE: In the Entry column, enter your information between the dashes. The entries automatically update matching document properties. Document Property Entry Master Owner Master Number -0- -Daniel Migliori- Increment revision numbers by one. Master Date -5/11/05- Number Date Owner Summary (Brief description of major changes) 0 5/11/2005 Daniel Migliori Original development CIS_302_Variable_Frequency_Design_Guidelines_WHQ.doc, 0, October 2005 9
Summaries 9.1 Plant Customization Tracking Enter information in these tables to track revisions to plant customized documents. NOTE: In the Entry column, enter your information between the dashes. The entries automatically update document properties. Document Property Entry Plant Code -XXX- Plant Owner -Enter Name- Plant Number -0.0- Plant Date -3/29/05- Use the following format for the Plant Number: <Master Number>.<Plant Number> Number Date Owner Summary (Brief description of major changes) 0 CIS_302_Variable_Frequency_Design_Guidelines_WHQ.doc, 0, October 2005 10