I’d like to hear how some of you are handling Air Conditioner motor contributions in your models. I’m working off a one-line to build the model (while the site is under construction!). I’m wondering if most people model the various motors separately (compressor, fan, other?), or do you leave them modeled as one.
Also, as some of the motors may be buried in the equipment, do you always verify RPM, service factor, FLA, and other motor nameplate data?
I’m not sure some of this data will even be available as these motors may or may not be NEMA standard motors… READ MORE.
I recently came across a previous study that was completed for a facility that assumed a specific type of conduit [non-metallic/magnetic; PVC] vs what was actually installed [Rigid Meal Conduit], in digging into this deeper and looking at some of the short circuit calculations information available to me it appears that in the calculation they type of conduit [magnetic vs non-magnetic] can play a role in the amount of available fault current. When doing some quick simplistic calculations it appears that the conduit material does play a role and in larger systems could make a difference. I did some digging in my software’s reference material and some other material but could not find adequate explanation / technical data.
I was hoping someone could share or point me to some additional resources on how conduit material affects available fault current? It appears there are different constants for conductors based on the type of installation [conduit type for systems of .208-13.2kV] also what if you have conductors installed in tray [3-1/C cables] does the spacing and configuration of how the cables are installed come into play and where could I find some information on this. Thanks in advance. READ MORE.
About Jim Phillips, P.E.: Electrical Power and Arc Flash Training Programs – For over 30 years, Jim Phillips has been helping tens of thousands of people around the world, understand electrical power system design, analysis, arc flash and electrical safety. Jim is Vice Chair of IEEE 1584 and International Chairman of IEC TC78 Live Working. He has developed a reputation for being one of the best trainers in the electric power industry, Learn More.
Click here for upcoming Arc Flash Safety Training
Click here for all scheduled Electrical Safety Training
Click here to request an Onsite Training
Sign-up for my monthly publication “Grey Matter” which contains news about new standards, conferences, technical articles, Electrical Engineering news and more!