My source is 440V. So I need a 440V to 240/120V, 40KVA Transformer. It sound like you are telling me that as long as I keep my neutral and ground seperated I should be OK on a marine vessel?
On this same vessel there is a 690V to 230V, 3 phase, 150KVA Transformer. The vector group indicates...
I was tasked to add a 240/120v single phase transformer and panel on a marine vessel. I have access to 440V 3 phase. I have no marine experience. Is there a special type of transformer I will need? A vendor mentioned to me that nothing should be grounded on a marine vessel. Can someone guide...
Sorry I'm just a designer and he still doesn't get it. So now I explained it to a Chemical Engineer and he understands so he is going to explain it to my boss EE. Man it is hard to try to do the right thing.
I just called the city inspector and he told me as other told me, as others told me, in this forum that the emergency lights with battery back up power must be feed from the same circut as the lights in the vicinty. My boss is going to have a cow!
BJC, The client and my boss want to use fixtures with battery back up in them. With that being said, my boss is telling me that the supply circuit feeding these battery back up fixtures is an “emergency circuit” and must come from a dedicated circuit along with being installed in it own...
Sorry for the re-post! I am just frustrated! I keep tell my boss what was said in the forum and the way I interpret the NEC Code art. 700, and he keeps telling me that we are all wrong. I also think it smarter to tie into the lights in the vicinity so if a breaker trips at night and the...
I have an emergency exit and emergency back up lights that all have battery back up power. My boss is telling me that the circuit that feeds the back up lights and exit sign must be on its own circuit in its own conduit. I’m telling him that the battery is the “emergency circuit” and other...
Correct me if I'm wrong. 700.15 states "No appliance and no lamps, other than those specified as required for emergency use, shall be supplied by emergency lighting circuits.
In my case the battery is the "emergency circuit" so the "normal supply circuit" can feed the emergency lights along...
BJC,
I am only using 3.5VA/sq ft to determine the "Minimum Lighting Load" as shown on table 220.12. I'm actually going to have 1 lighting panel, 2 power panels (one for each floor, 1 equipement panel and 1 computer panel. For the power panels I estimated 180AV per receptical plus the VA for...
I'm designing the electricl lighing and exit signs for a stairway in an office building. I have spec'ed out exit lights and stair lights with battery backup in each fixture. My question is because I have battery backup in each device, do these fixtures have to be feed on their own circuit? or...
I’m trying to figure general Lighting Load on an office building that is 11,400ft2. Using table 220.12 I will multiply 11400ft2*3.5VA/ft2 =39,900VA.
The part I’m confused about is how to calculate the amperage to size the 208Y/120V panel. Would it be calculated as 39,900VA/208*1.73?
I think...
If I understand the code correctly I can put 5KV and 15KV MV Cable in the same cable tray without haveing any barriers or up sizing the 5KV's insulation. Is this correct?
JMatt,
Thanks for the info. on the multiconductor cable and Tray. Does anyone else know where I can find the same infomation for conduit? I was told I can't mix 300v and 600v cables in the same conduit even though the voltage is 24v for all cables.
I have a substation in a Class 1 Div 2 area. Can I bring Tray Cable through the subs bulkhead via a Myers Hub and a CGB fitting? Will this be sufficient for the classification?
I don't do MV cable much and I'm a little confused on an grounding issue. I have 13.2kv coming form a overhead line going underground to Switchgear. I'm pulling single conductors MV Cable in the conduit. Should I ground the shields just at the Overhead pole or at both the pole and the...
I have a situation where I need to run 9 medium voltage cables in an underground duct bank. Looking at the NEC, if I run these in concrete duct bank I need to keep a 7.5” spacing center to center.
I have a client that wants to bore a 24” casing under a road and pull 9-5” pvc conduits in the...
I’m about to order a transformer and was wonder if I need fusing in the transformer to protect the secondary buss?
I have 13.2KV going through a fused (175E fuse) disconnect to a 13.2kv to 480v, 2500kva, Delta-wye, Transformer then feeding a MCC through a 3200a breaker. I do not have any...
I'm doing a project in an old plant where there is a 13.2kv to 480v, 1500kva, delta - delta transformer. The 'B' phase on the secondary is grounded. What advantage or disadvantates of this phase being grouned? Why not just have a floating ground?
