Circuit Breaker Mounting


Mounting refers to the way in which a circuit breaker is physically attached to a panel or mounting plane. It does not refer to any type of electrical connection.

Carling Technologies' circuit breakers can be of the "front mount" or "back mount" type. Front mount circuit breakers are attached to a panel; back mount breakers are attached to a back mounting plane, which may or may not be part of a panel enclosure. For both front and back mount styles, there are a variety of attachment options:

Snap-in Mount

The snap-in mount is a front panel mounting option where the circuit breaker is inserted through the panel cut out and snapped into place. The breaker is held in place by the pressure created between flexible, expanding barbs and a sturdy front lip (bezel overhang) which are molded-in features of the breaker shell. Snap-in mount circuit breakers require no external mounting hardware and therefore offer a quick, cost effective, and aesthetically pleasing mounting style.

Carling Technologies' A-Series Handle, B-Series, M-Series, and Q-Series circuit breakers offer this front snap-in mount style. To further address mounting and aesthetic options, the A Series & B Series circuit breakers offer a choice of bezel overhang widths of .75 inches per pole, .96 inch for single pole, or .105 inch for multi-pole breakers.

Screw Mount

The screw mount option can be of the front or back mount type. For front mounting, Carling Technologies' circuit breakers provide two threaded inserts per pole located on the front of the breaker. Carling's A-Series, B-Series, C-Series, circuit breakers offer both American Standard and Metric threaded inserts: 6-32 x 0.195 inches deep or ISO M3 x 5mm deep. The E-Series breaker offers threaded inserts of 6-32 x .220 inches deep or M3 x 5.59mm deep. And the Carling F-Series breakers offer threaded inserts of #10-32 x .300 inches deep or M5 x 7.62mm deep.

For back mounting, the Carling E-Series circuit breakers offer a short (.125 inches) or long (.485 inches) mounting foot that can accommodate #10-32 or M5 sized screws. The F-Series circuit breaker provides a clearance hole for a #10-32 screw that runs front to back through the circuit breaker.

External mounting hardware is not included with Carling's screw mount circuit breakers.

DIN Rail Mount

Designed to European DIN standards, DIN rail is a symmetrically bent, metal rail-mounting strip which is attached to a back-mounting plane. DIN rail mount circuit breakers are designed to attach to this DIN rail strip. Carling Technologies' D-Series and SmartGuard (PD-Series) circuit breakers offer snap-on-back mounting for either 35mm x 7.4mm or 35mm x 15mm symmetrical DIN rail. This snap-on-back feature requires no external mounting hardware, thereby allowing for quick and simple mounting and removal of the breaker.

Bushing Mount

Carling Technologies' M-Series paddle, baton, and pushbutton circuit breakers are front mounted bushing breakers. The M-Series threaded bushing is .500 inches in diameter and .470 inches long and fits a .500 inch diameter mounting hole. These bushings accommodate a variety of panel hardware options to offer the maximum of aesthetic choices. Such hardware options include knurled nut or panel dress nut with a bright nickel finish, black knurled nut or black panel dress nut. All panel hardware can include locking rings. Legend plates are also available. Incorporated within the Carling catalog-ordering scheme, external panel hardware is included among the circuit breaker options.

Form & Fit, Cut-out Dimensions Available

On-line PDF files of form-and-fit drawings, along with panel cut out dimensions, and catalog-ordering schemes are available for each Carling Technologies circuit breaker product series. Simply go to the product page of a specific series on this web site and click on the PDF icon.