You haven't been told you can't use NM-B to wire a fixed circuit from the breaker panel to a wall outlet. You can. That's why an electrician is able to do so and have the work pass inspection.
You keep getting hung up on "hot" and "neutral". But a circuit has two wires. You can think of them as "out" and "back". Whatever current flows "out" has to flow "back". 20 amps out, 20 amps back. The current in the two conductors is always equal and balanced. That's why you can't add up 20 and 20 to get 40.
You can work out for yourself why two 120 V, 20 A circuits do not add up to a 240 V, 40 A circuit. Think about it. 120 V x 20 A = 2400 W. Therefore 2 x 120 V x 20 A = 4800 W. But 240 V x 40 A = 9600 W. And 4800 W does not equal 9600 W. It doesn't add up.
If your load draws 30 amps then the "out" wire has to carry 30 amps and the "back" wire has to carry 30 amps, and each pole of the breaker has to carry 30 amps.
Thank you for explaining that. I want to apologize for my response last night. There's something really wrong with me and on Friday, the doctor said it was time to go to the ER. But I was waiting until Mothers Day was over with. I haven't gotten much sleep. I'm real worried now. I weighed around 207 lbs maybe 6 months ago and now I'm down in the 150 lbs, but nothing has changed. I just keep dropping it. At first, I was happy, but now, it's got us all concerned. I'm going to be going to the ER later today and might not be back for a bit.
I purchased a 40-amp double pole breaker.
So, is there any danger with going for a larger breaker than what is actually needed? I know I can run 14 gauge wire on a 20-amp breaker. I know I can't run 12 gauge wire on a 15-amp breaker. With this PDU and it's dedicated circuit, hypothetically, if I went for a 100-amp breaker, would that be dangerous? Essentially, would it only trip after it draws more than 100-amp or would it trip as soon as it noticed some sort of short or something? I'm not talking about GFCI breakers or arc-fault breakers. Just the normal D-Square Home-Line ones.
For the NM-B, I thought radar_macgyver said it's for in-wall use only. My receptacle is rated for the 32-amp, the proper mate to this plug. When it says 32-amp, being a European plug, I believe that's 40-amp derated to 80%. I believe that's how they categorize their breakers, at the derated current.
I'll be using 8-gauge wire, but I need clarification on the NM-B. I see NM-B (non-metallic sheathed cable) may be used for both exposed and concealed work in normally dry locations at temperatures not to exceed 90°C (with ampacity limited to that for 60°C conductors) as specified in the National Electrical Code. NM-B cable is primarily used in residential wiring as branch circuits for outlets, switches, and other loads. NM-B cable may be run in air voids of masonry block or tile walls where such walls are not subject to excessive moisture or dampness. Voltage rating for NM-B cable is 600 volts.
For the receptacle, they show no bare copper wires being hooked up, so I was thinking of going for something like 8/3 without ground, but then using the neutral for ground. Would that be best or would it be better to go for 8/2 with ground, and just hook the copper ground to the ground pin? I'm bonding the PDU to the rack, and the rack to the bonding cable that bonds the ethernet, coax, gas-lines, waterlines, etc together. I know I have to mark any non-black wires with red tape or something to show the next person it's hot.
The reason I feel I need to understand this is because some kid (from the previous owners) did some electrical work and didn't do it right at all. I feel the need to be able to identify what's wrong in this house, electrical wise, and fix it. We have a daughter and I don't want the house burning down. A good example is the ground wire running to the gang boxes but not actually being hooked to the receptacles, not even the GFCI receptacles. That's just not safe at all. I went through and wired a pig tail to the switches and receptacles to fix that.