GS4 Drive (VFD) - Wiring and Grounding Tips and Tricks from AutomationDirect

RFI Jumper. There is a reason this warning is the very first thing you see in the GS4 user manual. Please read it, and in particular, understand that you are responsible for following any electrical codes that are required for your installation and that drives should be installed by qualified personnel. The manual is really good, and while this video gives you some good pointers, neither replaces your local codes or drive installation experience. Here we go … The Gs4 drive has a built-in RFI filter to help keep noise generated by the drive from getting back out on to the incoming power lines. Depending on your systems wiring, you may need to remove the RFI Jumper BEOFRE applying power. You need to remove the RFI jumper if The drive is connected to single phase power. The drive is using an asymmetric grounding system – that is, if one corner of the triangle is grounded, or if the center of one winding is grounded or if you have a system with no stable ground. You should also remove the RFI jumper if the system is using a floating ground or a high impedance grounding system. The RFI jumper is located in a different place on different sized drives, but they all work the same way. Loosen the jumper release screw – half a turn is all you need. Pull the RFI jumper out. Why do you have to remove the RFI jumper in these cases? Because all of these either have floating grounds or at least one part of the circuit that isn’t grounded the same way as the others. Which means the RFI circuit inside the drive will be used as path to a ground for those large currents, and the RFI filter simply isn’t designed to handle large currents. If you forget and leave the jumper in, you may hear a pop or even smell some smoke from the burned up RFI filter. Don’t freak out, the drive will still function, but you will probably have just lost the RFI Filter for good. Leave the RFI Jumper in if you are using a systemically grounded system where the ground path is always the same for all leads. And of course, don’t remove the RFI jumper when the drive is powered – you should always remove it BEFORE connecting to power – which you would need to do anyway if using one of the odd grounding schemes. Proper Drive Grounding is a key to getting the best possible performance out of your drive. Here are some tips: The GS4 Drive MUST have a grounding cable to meet safety regulations and you want to make sure that ground connection is less than 0.1 ohms. So, keepthose ground wires as short as possible. That ground connection has to be to the dedicated ground terminal inside the drive – Don’t assume your chassis mounts are good enough. When connecting multiple drives, each ground must be independent. That is, always connect Drive grounds in parallel like this: not Daisey chained like this. While you DO want to have a magnetic contactor between the power and the drive, DON’T use it to turn the drive on and off – that will shorten the life of the drive. Always perform on off using the drives controls. Route power and control lines separately so noise doesn’t get coupled from the AC lines onto the control lines. When the wires do cross, try to keep them at 90 degree angles to each other. Again, to minimize coupling of the noise. If you are using a special VFD power cable, use the manufacturer’s instructions for grounding. If you are using conduit, then use it in accordance with your local codes. Otherwise, ground both ends of the shield or conduit of the power lines. If you need a load reactor, then install it on the output terminals and as close to those terminals as you can. Don’t use a Capacitor, an L-C Filter or and R-C filter on the output lines to the motor. When using a GFCI, select one with a current sensitivity 200mA or higher and not less than 0.1 second operation time to avoid nuisance tripping. The GS4 Manual has a table that tells you by drive model number exactly what wire ranges are acceptable and what torque to use for the main circuit wiring. And notice that while crimp terminals are not required for the smaller drives – though highly recommended - they ARE required for the larger drives starting at size D0. I love that the manual has line drawings of the terminal layout for each drive size – that helps me plan things out. And look, it even has a wiring diagram for each frame size so you know what to expect when you wire these up. That should be enough to get you started, but remember – this video just highlighted some of the main points. Everything you need to know about wiring a GS4 Drive can be found in chapter 2 of the user manual, so be sure to read that carefully before connecting your GS4 Drive. Click here to learn more about the GS4 Drives. Click here to learn about AutomationDirect’s free support options, and click here to subscribe to AutomationDirect’s YouTube channel so you will be notified when we publish new videos.