Donald Hester
Washington State Licensed Home Inspector #647
WSDA#80050
InterNachi Member #NACHI10022401
509-670-9572
Contact Us
Washington State Licensed Home Inspector #647
WSDA#80050
InterNachi Member #NACHI10022401
509-670-9572
Contact Us
DonHester's blog
A walk in time with Walker Electric Load Centers and more
Submitted by DonHester on Sat, 05/09/2015 - 10:02.
A walk in time with Walker Electric Load Centers and more. Wenatchee Home Inspection
In the world of home inspections we see some older load centers(panels). On a recent home inspection I ran into a Walker Electrical panel.
The Walker Electrical Co. Inc. was a division of I.T.E. Circuit Breaker Company, of Atlanta, Georgia. ITE also is known for their famous Bulldog Pushmatic load centers. Walker Electric Co started back in 1939, with Ralph Walker as president. This is why you can find Walker Electric load centers with Bulldog Pushmatic breakers due to the association of these companies.
Walker Split Bus Load Center
Here above we have an old Walker Split-bus load center. You can see here in this photo the bolt on bus system used in these panels, much like its Bulldog counterpart. The only difference is this is not the push button breaker (pushmatic). Like many older panels the main issue is age. You will not be able to upgrade this panel to meet some of the new requirements for AFCI's.
Walker Load Center with Pushmatic Breakers
Legend from the Walker Load Center
This is the legend showing Walker Electric at top and at the bottom stating “USE ONLY BULLDOG PUSHMATIC CIRCUIT BREAKERS IN BRANCHES”
Old promotional from ITE
There is another item to think about, many of these older breakers may have a lower interrupt rating also such as 5,000a vs 10,000a we typically see in more modern breakers. This is important in how the breaker will handle a short circuit.
From Bussmann-
"A protective device must be able to withstand the destructive energy of short circuit currents. If a fault current exceeds a level beyond the capability of the protective device, the device may actually rupture, causing additional damage.
Thus, it is important when applying a fuse or circuit breaker to use one which can sustain the largest potential short-circuit currents. The rating which defines the capacity of a protective device to maintain its integrity when reacting to fault currents is termed its “interrupting rating”. The interrupting rating of most branch-circuit, molded case, circuit breakers typically used in residential service entrance panels is 10,000A. (Please note that a molded case circuit breaker's interrupting capacity will typically be lower than its interrupting rating.) Larger, more expensive circuit breakers may have interrupting rating of 14,000A or higher."
From the 2014 NEC 110.9- Interrupting Rating
Equipment intended to interrupt current at fault levels shall have an interrupting rating at nominal circuit voltage sufficient for the current that is available at the line terminals of the equipment.
Equipment intended to interrupt current at other than fault levels shall have an interrupting rating at nominal circuit voltage sufficient for the current that must be interrupted.
In addition to the interrupt rating they might be more prone to failure than a new breaker.
Now back to the Walker Electrical, Bull Dog Electric Products and ITE History.
Walker Electrical was a division under ITE Circuit Breaker Company was owned by Cutter Electrical and MFG Co.. ITE became famous because of their innovative circuit breaker. The ITE Circuit Breaker Company was named after their innovative oil-dashpot “Inverse Time Element” (ITE) on its electro-mechanical circuit breaker trip devices, ITE was founded in the 1890’s in Philadelphia.
In 1928 because of ITE’s recognition in the electronics industry for their breaker design Cutter Electrical and MFG Co changed their name officially to ITE to take advantage of this name recognition.
Enter the BullDog. Bull Dog Electric Products was out of Detroit, Bull Dog Electric Products was bought by ITE somewhere around the 1950’s, these companies worked together and had relations as far back as the 1930’s. The Pushmatic breaker by Bull Dog dates back to 1934. I am unable to find the exact date when Bull Dog was purchased by ITE but the 1950’s seems to be appropriate. This is how Walker, Bulldog and ITE all become associated and why you will find these three names on equipment by them.
In 1968 ITE and Imperial-Eastman began a merger to form ITE-Imperial. From there in the 1970’s ITE-Imperial was bought by Gould which later was bought by Siemens and that gets us to where we stand today.
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NCW Home Inspections, LLC is a Licensed Washington State Home Inspection service located in Wenatchee Washington serving Chelan County, Douglas County, Kittitas County, Okanogan County and Grant County Washington and the cities of Wenatchee, Leavenworth, Cashmere, Oroville, Cle Elum, East Wenatchee, Quincy and many more…
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