Question 1. The state of California is under the 1996 NEC. In the county of San Mateo, we encounter many contractors who perform work in neighboring jurisdictions. In the installation of a Gas FAU (78 percent to high-efficiency), we see that the workmen install the unit with a flexible cord for attachment. They claim that other jurisdictions allow this connection and that it has become a standard of care. Certain inspectors in this department also accept such a connection. Their rationale is that the appliance (with a cord- and plug-connection) can be moved for service, replacement, and maintenance. Does this rationale hold up?

The purpose of this request is to get an answer as to what is acceptable and required in such an installation.
1. Is a cord- and plug-connection allowed?
2. If not, what is the minimum acceptable (or expected) installation?
3. Is a snap switch required?
4. Is a fused snap switch required?

Once this issue came up at an inspectors meeting, we decided that it was time for clarification on this matter so that we can develop some consistency in inspections in this county, regardless of what is happening in other counties. — K.C.

Answer 1. Is a cord- and plug-connection allowed? In the 1990 NEC, 422-8(c)(2) was revised to be consistent with the proposal that CMP-10 submitted to CMP-6, for inclusion in 400-7(a), that would prohibit the cord- and plug-connection of appliances that are fastened in place, unless the fastening means and mechanical connections are specifically designed to permit ready removal for maintenance or repair, and the appliances are identified for flexible cord connection.

The 1990, 1993, and 1996 NEC are the same for this section. In the 1999 NEC, the section was changed to 422-16 and in the 2002 NEC, the dash between the article number and the section number was changed to a dot. 

First, let’s set the stage. You have a gas-forced air unit (FAU) for heating a dwelling. The gas FAU is secured to the structure by mounting the unit in the attic, placing the unit in a garage or in a mechanical room, and connecting it to a base unit connected to gas fuel piping, made up of combustion air duct, exhaust vent pipe, air supply and return air ducts. None of these connections are specifically designed to permit ready removal. 

The ducts are connected to the gas FAU. The duct does not support the gas FAU; it is mounted first, then the ducts are connected to the unit

Therefore, the answer to the first question, is no. 

If not, what is the minimum acceptable (or expected) installation? 
The 2002 NEC states, “422.16 Flexible Cords. (A) General. Flexible cord shall be permitted (1) for the connection of appliances to facilitate their frequent interchange or to prevent the transmission of noise or vibration or (2) to facilitate the removal or disconnection of appliances that are fastened in place, where the fastening means and mechanical connections are specifically designed to permit ready removal for maintenance or repair and the appliance is intended or identified for flexible cord connection.”

It should be understood that a cord-connected appliance is required to be specifically designed, mechanically and electrically, to be readily removable for maintenance and repair.

Section 400.7 gives the uses that are permitted: “(A) Uses. Flexible cords and cables shall be used only for the following: … (8) Appliances where the fastening means and mechanical connections are specifically designed to permit ready removal for maintenance and repair, and the appliance is intended or identified for flexible cord connection.” 

This is not a dishwasher, compactor, or disposal that needs frequent removal for maintenance or repair and is permitted by the National Electrical Code to use flexible cords. 

This is commonly referred to as a valley practice, which is a way of saying, “We don’t know where it came from, but we have been doing it this way since 1947" and then show you their most current code book, which is a 1947 National Electrical Code.

Cord- and plug-connected appliances have a cord connected to them at the factory and are listed that way. The National Electrical Code has a few exceptions for cord use for specific appliances that come from the factory without cords and can be listed with and without cords. They are as follows: (a) disposal, (b) dishwasher, (c) compactor,  (d) range,  (e) cook top. 

Therefore, the answer to the second question is no.

Is a snap switch required?
The answer to the third question is yes, and you may use a snap switch for the disconnecting means. 

The 2002 NEC section describing disconnecting means is as follows: 

“422.30 General. A means shall be provided to dis