Danfoss 102 Operating Instructions Manual

Also see for VLT HVAC Drive FC 102: Service guide Programming guide Installation guide Installation guide Operating guide

Contents

• Do not ground one frequency converter toanother in a “daisy chain” fashion• Keep the ground wire connections as short aspossible• Using high-strand wire to reduce electrical noiseis recommended• Follow motor manufacturer wiring requirements2.4.2.1 Leakage Current (>3.5 mA)Follow national and local codes regarding protectiveearthing of equipment with a leakage current > 3.5 mA.Frequency converter technology implies high frequencyswitching at high power. This will generate a leakagecurrent in the earth connection. A fault current in thefrequency converter at the output power terminals mightcontain a DC component which can charge the filtercapacitors and cause a transient earth current. The earthleakage current depends on various system configurationsincluding RFI filtering, screened motor cables, andfrequency converter power.EN/IEC61800-5-1 (Power Drive System Product Standard)requires special care if the leakage current exceeds 3.5 mA.Earth grounding must be reinforced in one of thefollowing ways:• Earth ground wire of at least 10 mm2• Two separate earth ground wires both complyingwith the dimensioning rulesSee EN 60364-5-54 § 543.7 for further information.Using RCDsWhere residual current devices (RCDs), also known as earthleakage circuit breakers (ELCBs), are used, comply with thefollowing:Use RCDs of type B only which are capable ofdetecting AC and DC currentsUse RCDs with an inrush delay to prevent faultsdue to transient earth currentsDimension RCDs according to the system configu-ration and environmental considerations2.4.2.2 Grounding Using Shielded CableEarthing (grounding) clamps are provided for motor wiring(see Illustration 2.7).130BA266.10+DC BR- BM A I N SL1 L292RELAY 1 Y 299- LC -V WMOTORIllustration 2.7 Grounding with Shielded Cable2.4.3 Motor ConnectionWARNINGINDUCED VOLTAGE!Run output motor cables from multiple frequencyconverters separately. Induced voltage from output motorcables run together can charge equipment capacitors evenwith the equipment turned off and locked out. Failure torun output motor cables separately could result in deathor serious injury.• For maximum wire sizes see 10.1 Power-dependentSpecifications• Comply with local and national electrical codesfor cable sizes• Motor wiring knockouts or access panels areprovided at the base of IP21 and higher(NEMA1/12) units• Do not install power factor correction capacitorsbetween the frequency converter and the motor• Do not wire a starting or pole-changing devicebetween the frequency converter and the motor• Connect the 3-phase motor wiring to terminals96 (U), 97 (V), and 98 (W)• Ground the cable in accordance with groundinginstructions provided• Torque terminals in accordance with theinformation provided in 10.4 ConnectionTightening TorquesInstallation VLT® HVAC Drive Operating InstructionsMG11AI02 - VLT® is a registered Danfoss trademark 132 2Phone: 800.894.0412 - Fax: 888.723.4773 - Web: www.ctiautomation.net - Email: info@ctiautomation.net