Safety Notice: working with electrical equipment can involve fire, and fatal shock hazards. Electrical repairs must be performed by a qualified, licensed professional electrician. Good workmanship, following manufacturer's instructions, and local and other appropriate code compliance are also essential for a safe and successful outcome.

This is information for building inspectors, home buyers, home owners, and electricians regarding steps to reduce the hazards associated with Zinsco and Zinsco-type GTE Sylvania Zinsco circuit breakers and electrical panels. Safety warning: as with any electrical installation or repair, these steps must be performed by a licensed and qualified electrician and must comply with appropriate building codes and regulations.

Good workmanship and an accurate assessment of the condition of the electrical panel enclosure which is to be re-used are important for Zinsco Electric Panel.

We do not recommend mere replacement of Zinsco circuit breakers themselves.

Option1 - replace the Zinsco Sylvania panel interior bus assembly using a retrofit kit: The first section of this document OPTION #1 RETROFIT KIT describes how to replace Zinsco or Zinsco-type Sylvania Electric Panels in buildings using a retrofit kit provided by Eaton Corp., Cutler Hammer Products (E-CH): Option 1 - replacement of the panel bus assembly or "load center" while leaving the original electrical panel enclosure or "box" and its attached wires intact, by using the Eaton Corp., Cutler Hammer Products (E-CH) "Adjustable Retrofit Kit".

Option 2 - replace the entire Zinsco Sylvania electrical panel: In a second document section OPTION #2 REPLACEMENT we discuss Option 2 - conventional complete removal and replacement of the entire electrical panel.

Comparison of Options 1 & 2 for Zinsco electrical panel repair or replacement: In a third document section OPTION #1 vs OPTION #2 we express an opinion which compares these two methods.

Where the original panel enclosure is in good condition, Option 1 should cost less and be a faster job than Option 2 because less labor and less disruption is involved. We do not recommend mere replacement of Zinsco circuit breakers themselves, as discussed at the REPLACEMENT BREAKERS link at below-left. This is information for building inspectors, home buyers, home owners, and electricians regarding steps to reduce the hazards associated with Zinsco Electric circuit breakers and service panels.

Safety warning: as with any electrical installation or repair, these steps must be performed by a licensed and qualified electrician and must comply with appropriate building codes and regulations. Good workmanship and an accurate assessment of the condition of the electrical panel enclosure which is to be re-used are important for Zinsco Electric Panel

OPTION #1 RETROFIT KIT - Zinsco/Sylvania Panel Replacement - Option #1 Using the Eaton Corp., Cutler Hammer (E-CH) Products Adjustable Retrofit Kit

Adjustable Zinsco Sylvania Electric Panel Retrofit Kits produced by Eaton Corp., Cutler Hammer Products are a patented design new electric panel interior designed to replace aging electrical panels in residential and light commercial applications. The unique features are that the existing box and wiring can be re-used for convenience, if still in good working condition. Also, a custom trim to fit the existing box is available.

Using the retrofit kit involves disconnecting the electrical circuits from the existing load center "bus assembly" circuit breakers. The old bus assembly and other internal parts (neutral bus, ground bus, etc) in the existing panel are removed. The panel box or "enclosure" itself is left in place, and the electric circuit wires which entered that box are left undisturbed.

After inspection by the installer to confirm the soundness of the panel box, any openings in the box body are closed, a new load center (panel bus and circuit breaker set, ground and neutral bus bars) is mounted in the existing electric panel box, and the existing circuits are connected to the new circuit breakers.

The "field adjustable electric panel interior assembly" consists of an adjustable riser, the required interior bus assembly, and the appropriate neutral assembly and ground bar assembly. Additional kit components permit a new panel face to correctly fit the new bus assembly which has now been mounted in the old panel box.

On completion, all of the electrical parts inside the original electric panel have been replaced. Only the steel panel enclosure or "box" has been retained. The new parts and installation are made using UR and UL approved components. Wiring to comply with the electrical code, workmanship, and final code approval are the responsibility of the installing electrician, assured by an inspection by the local electrical inspector.

Not all Electrical Panels can be Upgraded using the Retrofit Kit - Size Matters

Field reports and comments from the manufacturer have pointed out that not every electrical panel is a candidate for upgrading using the retrofit kit discussed here. If the original electrical panel enclosure is itself too small to meet the size and space requirements of current electrical codes the entire panel will need to be replaced.

The following text provides an example of a case where, unfortunately, the old electrical panel was just too small to upgrade:

From email between a reader and the product manufacturer

While researching the service panel in a home I purchased this summer, I came across your retrofit kit for FPE service panels at http://InspectAPedia.com/fpe/fpereplace.htm I have a Stab-Lock C1410-14-125NI panel, 125amp, 120/240, 1 phase 3 wire. It currently has one 30a (dryer), one 40a (range) and one 50a (all other circuits) controlling 6 15a and 4 20a. I would like to upgrade to 150amp with a few more breaker spaces, if possible. The box measures 4 inches deep, 10 inches wide, 22-3/4 inches high inside measurements. The load center w/breakers is approximately 6-1/2inches wide by 15 inches high. The range wire is aluminum. I'm not sure if the incoming service wires are aluminum as well. The home was built in 1960. The existing panel is in excellent condition, no rust, all holes intact or in use. The existing wiring is in excellent shape. One local electrician told me that your product violates code.

Here is a clear and concise reply from the manufacturer:

Our retrofit kits are designed to be installed into enclosures where there is sufficient space to wire according to the National Electric Code. As the local electrician pointed out, the enclosure that you have is not large enough to allow for our kits to work. Being from 1960, the existing electrical panel was constructed prior to two NEC revisions that expanded the necessary wire bending space requirements. In addition, to increase the ampacity of the panel would require slightly more space. Unfortunately, for the application described, a new service will need to be installed.

WHY IT WORKS - Key Features of the Eaton Corp., Cutler Hammer Products (E-CH) Adjustable Retrofit Kit

Key in making this retrofit approach possible in the replacement of Zinsco or other problematic electrical panels is E-CH's development of:

Load Centers: a series of replacement load centers of varying capacity in amperage and number of circuit breakers, and varying also in overall dimensions

The Adjustable Retrofit Kit: which offers a set of parts which permit the new load center, mounted in the old electric panel enclosure, to be framed-in or enclosed properly regardless of the dimensions of the enclosure itself. The electrician simply measures the existing enclosure and orders the appropriate load center and adapter kit parts. The Adjustable Retrofit Kit parts may include:

A "picture frame" which adapts the existing enclosure to allow a new "trim/cover" assembly to be mounted as seen in the figure on page 2 of the E-CH product PDF file available here (450KB to download). The "picture frame" is .073 powder coat painted galvanized steel which not only adapts the trim to the existing enclosure, it extends past the enclosure edge several inches to provide a professional looking finish when the old plaster or drywall is damaged.

An adjustable "riser" combined with the adjustment feature in the dead front solves the depth issues and helps greatly when the old enclosure was not installed plumb/square.

The "trim/cover assembly" is the standard replacement loadcenter/panelboard trims that offered by CH as replacement items and as such carry the standard UL cabinet front label.

One of the biggest hurdles the manufacturer faced was the panel enclosure depth issue. To solve this, CH offers the adjustable depth feature. This allows the "riser" to be adjusted to accommodate enclosures from 4" to 6" in depth. When this is combined with the "picture frame" and "trim" the final product is a very safe, solid, and professional looking final assembly. To date (June 2006) CH engineers have not had any reports of any brand or model specific enclosure that these have not worked in. Due to the adjustability of the CH kit, it is unlikely there would be an electric panel model that these kits wouldn't fit.

Very shallow panel enclosures:

Eaton Corp., Cutler Hammer Products have just finished the design & patent work on phase 2 of this program. This will consist of an adjustable "extension collar" which will attach to the enclosure and extend it out from the wall for those installations that are very shallow. This will extend them out and then the standard "Retrofit Kit" can be used. This will accommodate enclosures clear down to 3" or less in depth.

More Reading:

Eaton Corp., Cutler Hammer Products Adjustable Retrofit Kit Ordering Instructions PDF file 450KB to download.

RETROFIT COST - Cost of Replacing an Zinsco Panel with the Eaton Corp., Cutler Hammer Products Adjustable Retrofit Kit

CH was unable to inform me of "typical" costs are hard to cite as there really isn't a typical application for this product - it is used in a wider variety of circumstances than just replacement of Zinsco electric panels or Zinsco-type Sylvania electrical panels. These vary from the smallest single phase, main lug, 125amp units to the largest three phase, main breaker, 42-circuit. 225-AMP kits.

In addition, custom size adapter collars can add to the costs as well. Materials costs typically run from $225 to $500 per kit plus installation cost. From the feedback CH has received from the field, when you figure in labor, the installed kit is less than half the cost of Option #2 - complete removal and replacement of the electrical panel. That is exactly in line with my own (DJF's) guess based on the labor and building disruption savings. If there is much cosmetic work with the Remove-and-Replace process, the savings are even greater.

Quotes from electrical contractors on Zinsco electrical panel replacement using the retrofit kit or using a complete new replacement electrical panel can be expected to vary by area of the country, hardware needed, replacement panel size in ampacity and number of circuits, accessibility to perform the work, and other factors that affect labor or materials.

That said, we've heard Zinsco Sylvania electrical panel replacement costs using the Cutler Hammer retrofit panel ranging from about $900. all the way up to $4000. If you are surprised by the quotation you receive from your electrician, ask for a bid from a competitor and compare labor, materials, and other costs.

See

REPLACEMENT PANEL COSTS for the latest data we have on typical electrical panel replacement costs.

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RETROFIT INSTALLATION - Eaton Corp., Cutler Hammer Products Hammer Adjustable Retrofit Kit Installation Tips

See the E-CH PDF file (450KB) which explains how this replacement program works. Obtain and follow the installation instructions that come with the equipment. Here are some additional comments:

Distinctive about this approach is that it is not necessary to cut the existing building wall for wire access, and not necessary to disconnect the existing circuits from the original metal panel enclosure "box". Avoiding these steps significantly reduces the labor and installation time.

The Adjustable Retrofit Kit installation procedure is roughly this:

Choose electrical load center size: select the proper sized load-center that will fit in the existing panel enclosure - measure the existing panel interior dimensions, including depth carefully.

Buy other electrical panel parts needed: if necessary, purchase additional panel enclosure parts such as a frame extension (if the panel Enclosure is too shallow) and a new panel cover front and door may be needed.

Disconnect the old electrical panel "bus assembly": remove the existing load center (power has been cut off of course). If I were doing it I'd Unscrew each circuit so as to have plenty of length to work with, but most will probably just Cut individual circuit wires close to the old breaker.

Remove the old Zinsco-Sylvania bus assembly: remove the old load center from the electrical panel

Cover the remaining electrical panel enclosure openings: cover with metal any improper openings such as knockouts (to assure that the existing enclosure is properly fire resistant

Install the new electrical panel bus assembly in the old panel enclosure: mount the new load center

Connect existing circuits to new load center: connect the existing circuits to breakers in the new load center

Install any "fit" parts needed: mount any panel enclosure box extensions (the "picture frame") and electric panel cover

Assure the Existing Panel Enclosure is Sound: before ordering the CH Replacement Load Center and Electrical Panel Enclosure Adapter parts, the electrical contractor should take a careful, honest, look at the existing enclosure. If it is not structurally sound don't use the retrofit kit. Some of those older enclosures are 50+ years old, rusted, bent up etc. In that case pull it out and start over. These kits are designed and intended to be used in good, safe, sound enclosures. [See More Reading below.'

Cover Openings in the existing panel enclosure (which is to be re-used). Any existing unused holes should be covered. On the smaller holes, this can usually be accomplished by inserting a pan head sheet metal screw of appropriate size to cover the hole. Any unused open knockouts in an enclosure should always be appropriately plugged whether it's a retrofit, repair, new installation etc.

Measure carefully: before ordering the particular retrofit enclosure parts, including the depth of the existing panel enclosure, so that the correct retrofit can be supplied.

Existing studs or other protrusions: if in the (to be re-used) panel enclosure there are existing studs in the old enclosure that are in the way these will have to be cut off and removed.

Flush Mount vs. Surface Mount: These are intended as a "flush mount" application. While they could be used as a "surface mount" the "picture frame" which acts as the adapter collar will extend past the edges of the existing enclosure and may not give a "finished" appearance. This may or may not be of consequence to the owner.

COMPONENT SELECTION - Selecting the Proper Retrofit Kit Components

By following the Zinsco Sylvania electrical panel "Retro Size Grid" on page 5 of the PDF file (450KB), in combination with the selection charts on the following pages, it can be determined just what exactly can be installed in which size enclosure and meet NEC requirements, wire bend etc.