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Is the flange that sticks down through the ceiling that the trim mounts through considered part of the points of support?

Posted By Underwriters Laboratories, Monday, September 01, 2003
Updated: Thursday, February 14, 2013

Question: Incandescent fixtures

Type non-IC, recessed incandescent fixtures are required to be spaced a minimum of 1/2 in. from combustible materials except at points of support. Is the flange that sticks down through the ceiling that the trim mounts through considered part of the points of support?

Answer

Type Non-IC recessed incandescent fixtures are Listed under the product category Incandescent Recessed Luminaires (IEZX), the UL Guide Information is located on page 45 in the 2003 White Book and includes important explanations of installation markings.

Here is an excerpt for TYPE NON-IC LUMINAIRES — "Recessed luminaires, except those identified as Type IC or for use in concrete only, are intended to be installed in an uninsulated or insulated ceiling (or wall), with all insulation kept a minimum distance of 3 inches from the sides of the luminaire and not placed over the luminaire such that it would entrap the heat produced by the luminaire. Other combustible materials are spaced, except at the points of support, at least 1/2 inch from the luminaire.

"For proper heat dissipation, Type Non-IC luminaires are intended to be installed in a cavity as follows: If not marked with any spacing information, the luminaire is intended to be installed not closer than 1/2 inch from any surface forming the cavity behind the recessed portion of the luminaire and not closer than 1 inch from adjacent luminaires.”

The plaster frame of the luminaire that is located at the bottom of the luminaire and is in contact with the backside of the finished ceiling is considered as a point of support. The flange that protrudes down from the luminaire through the ceiling that the trim mounts through is part of the plaster frame and is also considered as part of the points of support. Therefore, unless marked otherwise to identify that the luminaire is not suitable for installation in combustible construction, the flange does not need to maintain a 1/2 in. spacing to combustibles and may be in contact with combustibles.


 Question: Hydromassage bathtub

Are hydromassage bathtubs Listed for use in hospitals?

Answer

Hydromassage bathtubs are Listed under the category Hydromassage Bathtubs, (NCHX). The UL Guide Information for this category is located on page 234 in the 2003 General Information for Electrical Equipment Directory (White Book). This category covers indoor hydromassage bathtubs (also known as whirlpool baths) rated 250 V or less, for residential and commercial use, for permanent connection to the building plumbing, and intended for installation and use in accordance with Article 680 of the National Electrical Code. They are not evaluated or Listed for patient care use in healthcare facilities.

Hydrotherapy tubs evaluated for use in healthcare facilities are Listed under the product category Medical and Dental Equipment (KFBQ) or Medical Equipment (PIDF) located on pages 215 and 237 respectively of the 2003 White Book.

 


  Question: Terminals on receptacles

Some receptacles have both side and rear wiring terminals. Can I use both the side and rear terminals on a receptacle to tap off more than one circuit from the receptacle?

Answer

Receptacles are Listed under the product category Receptacles for Attachment Plugs and Plugs, (RTRT) located on page 102 in the 2003 General Information for Electrical Equipment Directory (White Book). The UL Guide Information states that:

"Single and duplex receptacles rated 15 A and 20 A that are provided with more than one set of terminals for the connection of line and neutral conductors may be used to feed a
single set of branch circuit conductors connected to other receptacles on a multi-outlet branch circuit. These devices have not been tested for tapping off more than one circuit from the receptacle by utilizing both the side-wiring and back-wiring terminals on an outlet.”

To further clarify this information, the RTRT Guide Information is being revised as indicated below. To properly address this question, we need to distinguish between back
wire (screw and clamp type) and push-in (screwless) terminals, since the usages differ.

"Single and duplex receptacles rated 15- and 20-amp that are provided with more than one set of terminals connecting line and neutral conductors may be used to feed branch circuit conductors connected to other wiring devices on a multioutlet branch circuit, as follows:

  • Back wire (screw and clamp type) terminations with multiple wire access holes may be used concurrently to terminate more than one conductor.
  • Side wire (binding screws) terminals may be utilized concurrently with their respective push-in (screwless) terminations to terminate more than one conductor. These devices have not been investigated to feed branch circuit conductors connected to other wiring devices on a multi-outlet branch
    circuit, as follows:
  • Side wire (binding screw) terminal with its associated back wire (screw and clamp type) terminal.
  • Multiple conductors under a single binding screw
  • Multiple conductors in a single back wire hole.”


Tags:  September-October 2003  UL Question Corner 

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