#7 - 20MWp PV Anlage - Fehlersuche - Messung Isolationswiderstand PV Anlage - Erdschluss? R-ISO PV

Today I'm taking you on a troubleshooting mission to a 20 MWp PV system. The operator informed me that a central inverter had failed due to insufficient insulation resistance (on the DC side). So, I had to go on-site to locate the fault. This system is an IT grid, meaning the live conductors are not grounded. To detect faults in the generator's insulation, special, continuously measuring ISOMETERS from BENDER are used. These cyclically measure the total insulation resistance of the affected area (all cables, lines, modules, etc. connected to this central inverter) between (+) / (ground) and (-) / (ground). If the ISO value falls below a certain threshold, the inverter is immediately shut down and disconnected from the AC grid. A minimum insulation resistance of at least 1 MOHM (based on a string at 1 kV) applies to PV systems. For a module, a minimum of 40 MOHM per m² must be maintained, which means for a central inverter with (as in this case) 3,072 modules - (40 MOHM/1.7 m²/3,072 = approx. 8 kOhm - this value is stored as the shutdown threshold in the inverter. In this video, I demonstrate an example approach for locating an insulation fault. First, the fault is roughly narrowed down and finally pinpointed to a specific component (module, cable, etc.). Experience and systematic approach help to achieve the goal relatively quickly - and of course, every fault found is a small joy :-) I expressly point out that work on electrical systems may only be carried out by qualified electricians, as required by law. I assume no liability whatsoever for the technical, legal, or safety-related accuracy of the content in this video. Electrical Installation/PV Measurement Equipment: *Beha Amprobe 2-Pole Voltage Tester: https://amzn.to/3hOZGSp *Fluke 381 Clamp Meter: https://amzn.to/3986xCh *Fluke 325 Clamp Meter (Small): https://amzn.to/3s0j5nT *Fluke 289 Industrial Multimeter: https://amzn.to/3nUsrhQ *Fluke 1507 Insulation Tester: https://amzn.to/3bOBUVv *Fluke IR Thermometer: https://amzn.to/3sKkeR4 *Fluke Padded Case for Measurement Equipment: https://amzn.to/3bOBUVv *Fluke Twist Guard Test Probes: https://amzn.to/39wuYtd *Fluke Master Test Lead Set for Industry: https://amzn.to/3bPxCNF *Fluke Installation Tester 1664 FC: https://amzn.to/2NeFvSC *Fluke Appliance Tester 6500-2: https://amzn.to/2NeFvSC *PV Benning PV Installation Tester PV 1-1: https://amzn.to/38nfpop *PV Benning PV Tester PV 3: https://amzn.to/399wQbo *PV MC4 Test Lead Set: https://amzn.to/2XwBCdL 18 Volt Cordless Tools Bosch Professional: *Cordless Screwdriver 18V GSR 18V-28: https://amzn.to/3szev0i *105-Piece Drill and Bit Set: https://amzn.to/38Rf65I *35-Piece Bit set: https://amzn.to/35QiYSF *GBH 18V-26 hammer drill: https://amzn.to/39A5Kdu *7-piece SDS-Plus drill bit set: https://amzn.to/3nNYsYU *SDS-Plus hammer drill bit: https://amzn.to/3nPSpmt *GDE 18V-16 dust extractor: https://amzn.to/3nPY6kB *GWS 18-125 angle grinder: https://amzn.to/35LpfPp *GKS 18V-57 G circular saw: https://amzn.to/3im37QJ *GOP 18V-28 multi-cutter: https://amzn.to/3szovGP *GDS impact wrench 18V-300: https://amzn.to/3bL0OW5 *GLI 18V-4000 C Construction Spotlight – 4000 Lumens: https://amzn.to/2LY7JjZ *2 ProCORE 18V 8Ah Batteries: https://amzn.to/3p7GvpP Hand Tools: *VDE Super Knips 125mm: https://amzn.to/3nPZKm1 *VDE Heavy-Duty Diagonal Cutters 200mm: https://amzn.to/3ip9EKq *VDE Cable Shears 200mm: https://amzn.to/39GAZ71 *VDE Cable Cutters 280mm: https://amzn.to/3qoWYG6 *VDE Electrician's Scissors 155mm: https://amzn.to/35Ol3hC *VDE Needle-nose pliers 200mm born:https://amzn.to/38YyzS9 *VDE needle nose pliers 200mm straight:https://amzn.to/2XPYswT *VDE Cobra 250mm: https://amzn.to/3bPZ4Lm *VDE pliers wrench 250mm:https://amzn.to/3qsPqlO *VDE Alligator 250mm: https://amzn.to/3oUp9MJ *VDE combination pliers 200mm:https://amzn.to/3ikEW5a *VDE Wiha screwdriver set 12 pieces: https://amzn.to/3nDTihX *ErgoStrip Abmantler:https://amzn.to/39Lpb38 *Wire stripper 16mm²: https://amzn.to/3qsYKGi *Twistor crimping pliers for wire end ferrules up to 16mm²: https://amzn.to/3c22n2b *MultCrimp crimping pliers: https://amzn.to/3sBSiyI *VDE socket wrench set: https://amzn.to/3nUEuf4 *PV crimping pliers from 2.5 to 6mm²: https://amzn.to/3np6uag *PV wire strippers from 1.5 to 6mm²: https://amzn.to/3pQa8f8 *PV metal assembly tools: Please contact me directly! ([email protected]) *PV professional tool case for photovoltaics: https://amzn.to/2XkWRPy *Affiliate links/advertising links. The links marked with an asterisk (*) are Affiliate links. If you click on an affiliate link and purchase through it, I receive a small commission to support this channel. The price will not change for you. Imprint: Thomas Böhm Small Business Hörlitzer Str. 34 01968 Senftenberg [email protected]