The columns indicate how much amperage is required to raise the temperature of that size conductor to that column's temperature under standardized conditions. So a 2/0 XHHW will reach 75°C at 135A and 90°C at 150A. The wire insulation is good for 90°C, so for sizing the wire, we can use the...
Grounding in NEC has become a cruel joke. It’s like tge stupid 25 ohm maximum rule, OR just use 2 rods. Granted the Earth electrode isn’t as critical as they make it out to be, or they would just stop with saying 25 ohms or less and basically we don’t care how you get there. I’m not a fan though of anything but a single point ground rod ...
For a given column of Table 300.5 ("minimum cover requirements") there is a potential overlap of the various rows. The one that concerns me at present is Column 2 (IMC and RMC conduit). If it's buried in a trench below 2" of concrete or equivalent, but also goes under a parking area in a...
The NEC does not define ranges, ovens or cooktops but based on manufacturers usage a range is a unit that has a cooktop and oven built together in one appliance. An oven is just a single or double appliance for baking , roasting, etc. A cooktop is just the burners without the oven.
NEC 2017 514.8 Underground Wiring. ENHANCED CONTENT Fuel spilled in the vicinity of gasoline dispensers seeps into the ground and could migrate into underground electrical conduits. Therefore, all conduits installed below the hazardous locations of a motor fuel dispensing facility are required to be sealed within 10 feet of the point of emergence from below grade. This boundary seal minimizes ...
NEC 2017 625.54 Ground-Fault Circuit-Interrupter Protection for Personnel. All single-phase receptacles installed for the connection of electric vehicle charging that are rated 150 volts to ground or less, and 50 amperes or less shall have ground-fault circuit-interrupter protection for personnel.
Is there any code against having wires from multiple power sources using the same conduit? I know article 300 says your aloud to use the same conduit for different voltages as long as all wires are rated for highest voltage present, and different voltages would mean different power sources. I...
80% rule applies to continious loads such as motors, lighting or any load expected to be on 3 hours or more. A breaker is rated for 100% of the noncontinious load which may include outlets or other small appliances. There are fully rated breakers / panels that are rated for continious use And will be listed for this application. It is a good practice to load branch circuits to a fraction of ...
Bob Badger said: There is no code to give you, the NEC does not say 'ground screws do not have to be green' the NEC just never requires box grounding screws to be green Yes if it has machine threads, see 250.8 Oh no not another box grounding thread. Maybe this one won't turn into "my way is common sense and just as good" like the last one did.
Good Morning Everyone, I Recently obtained a lead on a service upgrade. My question to the community pertains to working clearance of other utilities. I could not find any references in the 2020 NEC regarding clearances to gas lines. I'm aware of certain electrical equipment being readily...
