440, 460, 480 volts | Information by Electrical Professionals for ...
WEBJan 9, 2008 · This serves two purposes; it allows for voltage drop at the motor terminals and it falls within the NEMA MG-1 tolerance specifications (+- 10%) for the legacy systems that are still out there. For example, 440 +10% is 484, 480 - 10% is 432 so 460 falls smack dab in the middle and everyone is happy.
480 Volt Single Phase - Mike Holt's Forum
WEBJan 31, 2011 · A single 480-volt phase wire and a neutral would give you 277-volts unless it is a corner grounded system, just as on a 120/240 volt system one phase conductor and the neutral give you 120 volts. With a 480 volt single phase you would need two hot conductors (ungrounded conductors) and a grounding conductor - no neutral required.
Run 575 volt motors on 480 - Mike Holt's Forum
WEBDec 4, 2009 · This is exactly what happens in the situation described in this post - you supply 480 volts to 525 volt motor. Another example is 6 wire motor - if you connect it in Delta with 480v, the power is 100% but if you connect it in Star, where the coils receive 277v, the power is 33% (the voltage reduction squared).
Ungrounded Delta 480V/3-Phase/3-Wire System - Mike Holt's …
WEBMar 16, 2017 · I have a project where the existing pad mounted utility transformer is configured as delta-delta. The utility company says it is an un-grounded delta secondary at 480V/3-phase/3-wire system. I asked them to take voltage readings between phase-phase and phase-ground just to make sure it is an...
Voltage range for 480AC | Information by Electrical Professionals …
WEBJun 9, 2004 · Occupation. Professional Electrical Engineer. Jun 9, 2004. #4. Re: Voltage range for 480AC From IEEE 141 (Red Book) citing ANSI C.84.1-1989: Nominal System Voltage: 480V Nominal Utilization Voltage: 460V Maximum Utilization & Service Voltage: 504V (See note) Minimum Service Voltage: 456V Minimum Utilization Voltage: 440V …
480 volt 3 phase testing at panel | Information by Electrical ...
WEBMay 13, 2010 · I was testing a 480 volt 3 phase panel to industrial metal working shop. I was reading 480 volt to ground on 2 legs and less than 30 volt ac on the third leg. I have worked in numerous locations industrial and have not seen. seems to be a grounded leg?? I called electric company whom came out and found nothing wrong so I look stupid on this.
Difference between 460V and 480V regarding... - Eng-Tips
WEBOct 19, 2006 · This is mainly to cater for voltage drop. 480 volts is the system voltage. 460 volts is the rated voltage of your equipment. 460 volt rated equipment is always used on a 480 volt system to account for voltage drop due to …
General Electrical Question - 240 vs' 480 Volt Systems
WEBNov 25, 2006 · A component designed to operate at 480 volts has to have a thicker layer of insulation (or a better type of insulation), to prevent leakage current, that a component designed to operate at 120 volts. That has an impact on the size of …
480v. and 120v. in same conduit | Information by Electrical ...
WEBMar 26, 2005 · However, I would NOT install 480 ungrounded in the same pipe as 120 volts. 480 volts ungrounded systems have been shown to have an AC overvoltage of up to 2,000 volts from capacitance effects. I have installed both 120 volts 2-wire and 480 volts 3-wire off of a 277Y480 volts system with 200 amp class J fuses in the feeder.
Transformer for 480 volts to 380 volts | Information by Electrical ...
WEBJul 2, 2014 · 480 volt three phase down to 380 volt three phase. Transformers of this rating usually have a long lead time. Would there be anything wrong with using a three phase transformer with a 600 volt primary and a 480 volt secondary? With 480 on the primary, the secondary should produce 384 volts. Would the lower excitation