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Code conundrum February 2017 • Ray Yousef

February 14, 2017 | By Ray Yousef

February 14, 2017 – More on ampacity, combustible gas detection and pendant lampholders below!

The maximum ampacity for #6AWG T90 nylon run in a conduit containing 6 #6AWG T90 nylon, 12 #14AWG TWU75 and 7 #12AWG TW75 is:

a) 65A
b) 55A
c) 39A
d) 33A

Electrical equipment suitable for non-hazardous locations may be installed in a ventilated Zone 2 area when it is continuously monitored by a combustible gas detection system that automatically de-energizes the equipment when gas concentration reaches ___ of the lower explosive limit.


a) 10%
b) 20%
c) 30%
d) 40%

Pendant lampholders in Category 1 locations must be weatherproof, unlike Category 2, where corrosive liquids exist.

a) True
b) False

Answers to these questions next month. Meantime, here are the answers to the January 2016 Code Conundrum:

Question 1
Where non-metallic sheathed cable is exposed, switch, outlet and tap devices of insulating material can be used without boxes.

a) True. Rule 12-522(1).

Question 2
The minimum headroom around an elevator’s controller and disconnecting means shall be:

b) 2 m. Rule 38-005.

Question 3
Class 1 circuit conductors of #16AWG copper do not extend beyond the equipment enclosure and do not require overcurrent protection.
a) True. Rule 16-104(1).


• 3/3 = Master Electrician
• 2/3 = Journeyman
• 1/3 = Apprentice
• 0/3 = Plumber?!?

The Code Conundrum is compiled by Ray Yousef of Ontario’s Electrical Safety Authority.

N.B. Always consult your AHJ for more specific interpretations.

* This article also appears in the February 2017 edition of Electrical Business Magazine. Check out our ARCHIVE page for back issues.

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