How to Identify Zinsco Circuit Breakers with Pictures

We would like to help you to Identify your Residential Zinsco Circuit Breakers with Pictures

Zinsco History

Zinsco was originally the West Coast division of the Frank Adam Electric Company, whose main facility was in St Louis, Missouri, the company became independent as the Zinsmeyer Company following the onset of the Great Depression. The younger Zinsmeyer took over the company from his father in 1943 and renamed it Zinsco.[1] The company was sold in 1973 to GTE-Sylvania, who continued to manufacture breakers and panels to the original Zinsco design for some years; this product line is now discontinued.


The original Zinsco, Magna-trip Circuit Breakers came in Full Size Only. they we 3/4 Inch per Pole. They are called T-Type or

Feed Through because they would be installed, not by plugging them in but connecting them to a claw shaped piece of

copper that held more than one breaker

Below original Zinsco Feed Through with feed through mounting.


Please notice the copper red bracket in the Picture. Originals were mounted  like this.

Zinsco Circuit Breakers have been color coded to make it easier to identify, especially when the amperage on the handle is worn off.

Colors are as described below


15 Amp

red or Orange

20 Amp


  30 Amp


40 Amp


50 Amp


60 Amp

These, if used as Feed Through are Not no longer available unless it is used

Replacements are being made if used as a plug-in


Then the same were made for Plug-In with a clip on the rear that can be reversed to choose what phase

you wish to use. These can be used for feed through or Plug in (remove clip if used as feed through)

   t-front t-reart

The picture on the right shows the clip that is reversable to choose what phase.

It can also be removed to use as feed through

These may have Black handles for all amperages or the colored handles

For the plug in style there is a replacement being made


Now here is the Half Size. They are sometimes called piggy-back or Cheeters.

The R-38 is two 1 pole circuits that Work Independently of each other

The RC-38 is a Two Pole with the handles connected

Half Sizes are made so you can add more circuit to the panel by replacing full size with this half size.

Half size Zinsco R-38 RC-38 came with and without handel ties, and the wire was connected by a screw

or push pins or push pins

r38s                   r38152        r38202

Half size R38-30 Poles Each Independent         Half size 2 Pole see the                 Half Size 1 Poles Each

The grey one in the center is the new                  handles are connected              Independent not connected

Replacement Circuit Breaker

Buy 2 pole and Piggyback NOW For $48.00


Here is the Full Size  Zinsco Plug-ins

These are 3/4 inch wide per pole. Avoid the ones with the colored handles. The New Replacements meet today’s standards.


                                                                               One poles are Type Q                                                   

                                           Buy Now for $24.00


                                                                       Two Poles are Type QC

                                      Buy Now for $48.00



Zinsco Replacement Buss Bar Kits

There is a replacement Buss Bar Kit that is available if yous are Pitted. It is an economical solution if

replacing the panel is not an option

rbk  Buy Now for $79.00



All Zinsco Replacements Are Available at  JRL Electric Supply Inc.   Since 1985