Another Derating scenario, plus Boxfill example, too!

A continuation of the

Here's the Derating Discussion!!! Yee-Haww Thread, with a few twists!

BTW, I am just picking example scenarios from “Thin Air”, they are not any textbook exam examples, or from any on-line tests I am aware of.

(AKA “You are not doing my Homework for me” kind of thing…)

1: Which of the following examples is compliant per NEC Chapter 3:

<OL TYPE=A>

[*] Three 3 Phase 3 Wire circuits of #10 THW cu in same raceway, load = 26 Amps per circuit, non LCL, OCPD = 30 Amps,

[*] Six 1 Phase 2 Wire 230 Volt Resistance Heaters – each is 4.5KW rated @ 230 VAC, fed from 1 Phase System with #10 THHN cu in same raceway; non LCL, OCPD = 20 Amps,

[*] Four 1 Phase 3 Wire circuits of #12 THHN cu in same raceway, system is 1 Phase 3 Wire, each Multiwire circuit will be driving Continuous Non-Linear L-N loads, OCPD = 20 Amps,

[*] Four 1 Phase 3 Wire circuits of #12 THHN cu in same raceway, system is 208Y/120 VAC 3Ø 4 Wire, each Multiwire circuit will be driving Continuous Non-Linear L-N loads, OCPD = 20 Amps.

</OL>

BTW, Ambient Temperature is 30° C for all examples.

2: I ran Two 12/3 MC Cables (w/ Grounding Conductor), into a 4s 1-½” deep box. There will be a 125-Volt, 20 Amp Duplex Receptacle mounted on a 5/8” raised 1 Gang Plaster Ring when it’s trim time. The Receptacle will be connected to one of the Two branch circuits via “Pig Tails”.

Am I OK with boxfill here?

Are these examples OK?

Please submit any answers, questions, comments and/or examples you wish.

Scott35

Edited faulty Hyperlink

[This message has been edited by Scott35 (edited 09-27-2004).]