Selection Procedure for NQ Merchandised Panelboards

Online Refer to NQ Panelboards

Selection Procedure for NQ Merchandised Panelboards

  1. Review maximum electrical system voltage, ampacity, and available fault current, and determine the type of panelboard that is desired (see tables NQ Series Connected Circuit Breaker Ratings (RMS Symmetrical)Fuse/I-Line Circuit Breaker Series Connected Ratings).

  2. Identify type (plug-on or bolt-on) and total quantity of branch circuit breaker poles and panel spaces required (see Digest sections 7 and 9 for catalog numbers).

  3. Select proper main lug interior (from Main Circuit Breaker Interiors—Will accept plug-on and bolt-on circuit breakers or NQ 14-inch-wide Main Lug Interiors) or:

  4. Select ground bars from tables NQ Accessories or any non-standard neutral assemblies
    (i.e., 200% neutral for non-linear loads) from NQ Merchandised Neutrals.

    • Please note that an aluminum ground bar kit is included with NQ Panelboard Interiors.

  5. Select any required sub-feed circuit breakers, sub-feed lugs (SFL), or feed-through lugs (FTL) kits:

  6. Determine the total enclosure height required by adding requirements from interior, main circuit breaker, neutrals and ground bars, SFL, FTL, or sub-feed circuit breaker.

  7. Select enclosure from the tables NQ Main Lug InteriorsNQ Accessories, NQ Merchandised NeutralsNQ Optional Lugs, Sub-feed Circuit Breaker Cabinet Data, Sub-feed Lug Cabinet Data, and Feed-through Lug Cabinet Data.

    NEMA Type 1—select box and front (cover) catalog number corresponding to interior catalog number.
    NEMA Type 3R, 5, 12—select enclosure. Cover for Type 3R, 5, 12 is included with the enclosure.

  8. Select the branch circuit breakers to be installed in the panel.

    For NQ panelboards use QO (VH) or QH circuit breakers from Section 7 of the Digest, QOB(VH), or QHB circuit breakers from Section 9 of the Digest.

  9. Select options and accessories from tables NQ 14-inch-wide Main Lug InteriorsNQ Accessories.


    Additional NF and NQ options may be found in the Supplemental and Obsolescence Digest, Section 4.

NQ Merchandised Selection Example
208Y/120 Vac, 3Ø4W, 10 kA SCCR, 225 A, MLO, NEMA Type-1, surface-mount, bolt-on, branch circuit breakers, main sub-feed lugs


Table No.

Catalog Number


(20) 20/1

Standard Interrupting QOB 10,000 AIR Circuit Breakers

(20) QOB120 20
two 40/2

Standard Interrupting QOB 10,000 AIR Circuit Breakers

two QOB240 4
two 30/3

Standard Interrupting QOB 10,000 AIR Circuit Breakers

two QOB330 6
      Total 30 spaces


Table No.

Catalog Number

Min. Box Height

225 A MLO Interior Main Lug Interiors NQ430L2 32 inches
Enclosure (Box) Main Lug Interiors MH38
Front (Cover) Main Lug Interiors NC382S
Sub-feed Lugs

NQ Merchandised Sub-feed Lugs and Box Selection Table

NQSFL2 6 inches
      Total 38 inches

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