Cut Sheet

Technical Article
Leviton Mfg. Co., Inc. Lighting & Energy Solutions
20497 SW Teton Avenue, Tualatin, OR 97062 1-800-736-6682 Tech Line: 1-800-959-6004 Fax: [phone] www.leviton.com/les
© 2012 Leviton Manufacturing Co., Inc. All rights reserved. Subject to change without notice.
PL-PD-F007 Rev. 2 04/06/2009
3/4" space (use chase nipple)
3-1/2" deep
back box is
required
Four-gang wallbox Single-gang wallbox
Do my dimmers have to be installed in a specific order?
Yes, please reference the “Dimmer Sequence, Back-Box Size, and Fin Removal Chart” within
this document. It stipulates the sequence of dimmer installation. A specific sequence is
required to ensure that device mounting holes line up with your back-box device mounting
ears. The installation sequence is expressed by indicating where wide and/or narrow dimmers
should be installed. For example, if you have an installation with (3) wide dimmers and (1)
narrow dimmer, the indicated sequence is: “W+W+N+W” indicating that the installation or order
is WIDE-WIDE-NARROW-WIDE.
Will my dimmers have fins broken or not?
For most configurations including narrow and wide dimmers, there are two installation options,
one with fins removed where possible and ones with all fins intact. The fins removed
configuration allows you to keep the width to an absolute minimum while still getting the
maximum performance out of the dimmer. Although there are dimmer rating implications when
fins are broken, the decision to break them off or not is purely subjective. When in doubt, do
not break fins off.
When the decision has been made to remove fins, not all fins should be removed. Please
reference the “Dimmer Sequence, Back-Box Size, and Fin Removal Chart” within this
document. It stipulates which fins should be removed and which ones should be left intact. The
* indicates which fins are to be removed. For example, the string W*+*W+N+W indicates that
when you have (3) wide dimmers and (1) narrow dimmer and you intend to remove fins, the
fins should only be removed between the two adjacent Wide dimmers.
Since I have a multi-gang application, do I need to de-rate my dimmers?
Most multi-gang installations require some sort of de-rating to ensure that the dimmers do not
surpass their maximum internal temperature ratings. The amount of required de-rating is
determined by the dimmer model and whether 0, 1, or 2 fins have been removed. Reference
the charts below showing the rating of your dimmer determined by the number of broken fins.
What size back box do I need?
Once you’ve determined the number of narrow and/or wide dimmers and whether or not you
will be removing fins, the required back-box size can be simply determined by reviewing the
“Dimmer Sequence, Back-Box Size, and Fin Removal Chart.” Find the number of narrow
dimmers in the rows and the number of wide dimmers in
the columns. The intersection of the row/column plus
information about whether or not fins are removed
will lead you to the cell showing the
required back-box size. When you find
the syntax 4+1 in the chart, it means that
in order to accommodate this installation a
1-gang wall box should be installed adjacent to a
4-gang wall box. The two are joined with a ¾” chase
nipple.
What face plate do I need?
Like back-box size, the required face plate is determined by first establishing the number of
narrow and/or wide dimmers and secondly, whether or not fins will broken. The “Dimmer
Sequence, Back-Box Size, and Fin Removal Chart” also indicates which face plate is required
for each installation. Required face plates for common configurations are in stock at all times.
However, other configurations have a 4-6 week lead time for the face plate. Please make sure
to account for this lead time in your project schedule.