Power Distribution http://ecmweb.com/taxonomy/term/19951/more en Power Supply to TRU Stations http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/power-supply-tru-stations <div class="node-body forum-body"><p>Article 626 discusses Electrified Truck Parking Spaces. Section 626.11 states a minimum load of 11kVA for each space for calculation.&nbsp;I don&#39;t see any such statement for Transport Refrigerated Units (TRUs) in Part&nbsp;IV, Secs. 626.30 to 626.32.&nbsp; Does the 11kVA load apply here also or is there another way of determining what minimum load to use?&nbsp;Does the term &quot;Electrified Truck&quot; include the reefer unit or is that intended to be separate?&nbsp;I see mostly the trailers parked at the plug-in stations.</p> </div> http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/power-supply-tru-stations#comments Power Distribution Sat, 08 Apr 2017 21:24:31 +0000 147041 at http://ecmweb.com Phase Rotation http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/phase-rotation <div class="node-body forum-body"><p>We&#39;re a small utility looking to document the phase rotation&nbsp;on all of the three-phase applications in our system. The idea is that if a storm came through and knocked out multiple three-phase&nbsp;services we would have documentation to reference in order to build the system back&nbsp;efficiently.</p> <p>We&#39;re looking for suggestions concerning best practices in taking on this task.</p> <p>We have both &quot;Y&quot; and Delta banks in our system.</p> </div><p><a href="http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/phase-rotation" target="_blank">read more</a></p> http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/phase-rotation#comments Power Distribution Wed, 22 Mar 2017 16:31:23 +0000 146631 at http://ecmweb.com Help Select Wire or Cable, Please http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/help-select-wire-or-cable-please <div class="node-body forum-body"><p>First, I&#39;m not sure what is going on with the Category selections on this forum today. If the selection has a sub-list an error message appears. Thus, I selected &quot;Contests&quot; which might be appropriate, but I cannot offer any prizes since I&#39;m poor. ;-\</p> </div><p><a href="http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/help-select-wire-or-cable-please" target="_blank">read more</a></p> http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/help-select-wire-or-cable-please#comments Power Distribution Thu, 02 Mar 2017 23:45:09 +0000 145891 at http://ecmweb.com Line Loss Pro - anybody heard of it? http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/line-loss-pro-anybody-heard-it <div class="node-body forum-body"><p>Hello!&nbsp; New here, but long time pro-member of HVACtalk.</p> <p>We have been approached by a company called LineLossPro, who claims that by installing their &quot;device&quot; on our electrical panels, we will realize a 20-35% SAVINGS on our energy usage.&nbsp; Sounds fishy to me.....but I&#39;m wondering if anyone here has ever heard of them.</p> <p>&nbsp;</p> <p>Thanks in advance, and, as a career electrician, look forward to contributing to the forums!</p> </div> http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/line-loss-pro-anybody-heard-it#comments Power Distribution Tue, 31 Jan 2017 22:11:44 +0000 144851 at http://ecmweb.com 112kVA Transformer to Two 200A Panels http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/112kva-transformer-two-200a-panels <div class="node-body forum-body"><p>Hey guys,</p> <p>I&#39;m looking to clarify an install with a 112kVA&nbsp;transformer, 480V&nbsp;primary, 208Y&nbsp;secondary. The transformer is going to be next to dp and secondaries are going to be located next to the transformer&nbsp;so the within 10 ft&nbsp;distance rule will apply.</p> <p>My question is should I&nbsp;put a 400A&nbsp;fused disconnect and feed the two&nbsp;panels from there and go mlo at the panels or put a 200A&nbsp;main in each of the panels?&nbsp;The third option I&nbsp;guess would be feeding one&nbsp;panel and double lugging and feed 2nd panel from there.</p> </div><p><a href="http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/112kva-transformer-two-200a-panels" target="_blank">read more</a></p> http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/112kva-transformer-two-200a-panels#comments Power Distribution Sat, 21 Jan 2017 22:05:44 +0000 144661 at http://ecmweb.com 44kV Overhead Distribution In-line Switch Issue http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/44kv-overhead-distribution-line-switch-issue <div class="node-body forum-body"><p>I work with an electrical power distribution utility in Canada.&nbsp;We are trying to figure out the causes for the issue we experienced with Overhead Distribution Inline Switch in our 44kV network.&nbsp;We would like to know the causes faced by other LDCs and the steps taken by them to minimize the failures of overhead distribution inline switches in their 44kV networks.</p> <p>For example,</p> <p>1) What are the main causes of failures?</p> <p>2) What are the minimum operating standards for these types of switches?</p> </div><p><a href="http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/44kv-overhead-distribution-line-switch-issue" target="_blank">read more</a></p> http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/44kv-overhead-distribution-line-switch-issue#comments Power Distribution Tue, 22 Nov 2016 21:34:02 +0000 142841 at http://ecmweb.com Parallel Transformers http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/parallel-transformers <div class="node-body forum-body"><p>I could use some help please.</p> <p>I am looking at a facility with 3 parallel MV transformers. The electric utility is providing 26.4kV with a fault current of 31.5kA. The building&#39;s 480V&nbsp;switchgear is rated at 100kAIC. When questioned about the available short circuit rating the &quot;utility&quot; will only tell us it is 107kA at the line terminals of the switchgear.</p> </div><p><a href="http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/parallel-transformers" target="_blank">read more</a></p> http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/parallel-transformers#comments Power Distribution Tue, 22 Nov 2016 16:39:29 +0000 142831 at http://ecmweb.com Healthcare Facilities http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/healthcare-facilities <div class="node-body forum-body"><p>I am trying to find a standard on the electrical distribution in healthcare&nbsp;facilities, I have seen a hospital using a 2-phase system to distribute 220V, this is not suitable for class1&nbsp;medical equipment. I know it must be single phase and therefore I need an official document to prove this point.</p> <p>&nbsp;</p> <p>Looking forward to your help in this matter.</p> <p><a href="mailto:nexroom@gmail.com">nexroom@gmail.com</a></p> </div> http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/healthcare-facilities#comments Power Distribution Wed, 31 Aug 2016 07:32:59 +0000 139551 at http://ecmweb.com Chase Opening in the Bottom of a NEMA1 MSB http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/chase-opening-bottom-nema1-msb <div class="node-body forum-body"><p>Is there a NEC requirement to have a metal barrier under a MSB if the MSB is mounted on a wooden floor?</p> </div> http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/chase-opening-bottom-nema1-msb#comments Power Distribution Wed, 13 Jul 2016 18:01:51 +0000 137731 at http://ecmweb.com Cascading Circuit Breaker KAIC Ratings http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/cascading-circuit-breaker-kaic-ratings <div class="node-body forum-body"><p>Many years ago, I was instructed to cascade the KAIC rating of a circuit breaker distribution system so that the main circuit breaker had&nbsp;the largest KAIC&nbsp;rating. Every circuit breaker downstream of it was smaller and&nbsp;cascaded with a smaller KAIC&nbsp;value as it got&nbsp;farther away from the main circuit breaker. The smallest KAIC rating was based on the fault values of the utility company or transformer.</p> </div><p><a href="http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/cascading-circuit-breaker-kaic-ratings" target="_blank">read more</a></p> http://ecmweb.com/forums/electrical-equipment-systems/power-distribution/cascading-circuit-breaker-kaic-ratings#comments Power Distribution Tue, 24 May 2016 13:41:23 +0000 136161 at http://ecmweb.com