Code Q&A
Jul 17, 2008, By Mike Holt
Q. Is the required working space for a panel measured from the panel guts inside the panel or from the panel cover?...
Code Q&A
Jul 3, 2008, By Mike Holt
Q. What are the requirements when installing a 120V switch in the same box with a 277V switch?...
Code Q&A
Jun 19, 2008, By Mike Holt
Q. Can I use 14 AWG conductor pigtails from a 12 AWG, 20A circuit so that I can backstab the wires to the receptacle?...
Code Q&A
Jun 5, 2008, By Mike Holt
Q. I have a building that has two services from the utility. Do I have to use the same grounding system for both?...
Code Quandaries
Jun 1, 2008, By Mike Holt, NEC Consultant
Q. Can I connect the neutral conductor to the equipment-grounding terminal at both the transformer and the first disconnect?...
Code Q&A
May 16, 2008, By Mike Holt
Q. Can the lights in a dwelling unit bathroom be on the same circuit as the bathroom receptacles?...
Code Q&A
May 1, 2008, By Mike Holt
Q. Can a 2-pole snap switch be used to switch a 277V and 120V circuit?...
Code Quandaries
May 1, 2008, By Mike Holt, NEC Consultant
What are the requirements for installing isolated ground receptacles?...
Code Q&A
Apr 17, 2008, By Mike Holt
Q. I was told that a back-fed breaker needs to be bolted into the panel. Is this correct?...
Code Q&A
Apr 3, 2008, By Mike Holt
Q. Does the NEC require a connection of a parking lot lighting pole to a ground rod?...
Code Quandaries
Apr 1, 2008, By Mike Holt, NEC Consultant
Q. What size THHN conductor is required for a 320A 3-phase feeder load for commercial office buildings?...
Code Q&A
Mar 20, 2008, By Mike Holt
Q. Is GFCI protection required for drinking water fountains in office buildings?...
Code Q&A
Mar 6, 2008, By Mike Holt
Q. A 400A service is made up of two 200A main breaker panelboards that are nippled together. Can the service conductors pass through one of the cabinets to supply the other panelboard?...
Code Quandaries
Mar 1, 2008, Mike Holt ,, NEC Consultant
Q. When a single generator is used to provide standby power for emergency and nonemergency loads, can one transfer switch be used?...
Code Q&A
Feb 21, 2008, By Mike Holt
Q. What are the NEC requirements for the installation of smoke detectors in dwelling units?...
Code Q&A
Feb 7, 2008, By Mike Holt
Q. What are the Code requirements for bonding bushings on 277V or 480V branch and feeder and circuits?...
Stumped by the Code?
Feb 1, 2008, By Mike Holt, NEC Consultant
Q. What are the rules on spacing receptacles in a dwelling unit?...
Code Q&A
Jan 24, 2008, By Mike Holt
Q. When PVC conduit is used, does the Code require an equipment grounding conductor between the meter enclosure and the service disconnect?...
Code Q&A
Jan 10, 2008, By Mike Holt
Q. Section 110.14(C) requires the use of the 60°C column for 100A or less and the 75°C column for above 100A for conductor sizing. What is the value of THHN rated 90°C if the ampacity cannot be used for conductor sizing?...
Code Q&A
Dec 27, 2007, By Mike Holt
Q. Is there any allowance in the NEC to locate receptacles in dwelling units where it is convenient for furniture layout or the designer’s wishes, if the required number of receptacles is installed?...
Code Q&A
Dec 13, 2007, By Mike Holt
Q. Is it permissible to run heating/air-conditioning duct 4 feet above a panelboard if the ductwork services the room where the panelboard is located?...
Code Quandaries
Dec 1, 2007, By Mike Holt, NEC Consultant
Q. If structural steel is used as a grounding electrode for the electrical service, is it also necessary to supplement the steel electrode with an additional electrode such as a ground rod?...
Code Q&A
Nov 27, 2007, By Mike Holt
Q. A single main breaker is installed, then taps supply individual meters with disconnecting means for individual tenants. Should a main bonding jumper be installed at the single main breaker or at each separate disconnect?...
Code Q&A
Nov 13, 2007, By Mike Holt
Q. When a conduit leaves a Class I, Division 1 classified paint spray room and goes under the concrete floor into a cabinet in the motor control room that is non-classified, is one sealing fitting in the paint mix room sufficient, or is an additional sealing fitting required in the non-classified area as well?...
Code Quandaries
Nov 1, 2007, By Mike Holt, NEC Consultant
Q. What is the minimum depth for placing Schedule 40 PVC conduit below a concrete slab?...
