What is the replacement breaker for an NA1B Panel?
Circuit Breakers, NA1B Panelboards
Electrical Distribution Equipment
New or replacement breakers required
There have been two series of NA1B panelboards. There was a series built between 1934 and 1946 that used Type L branch breakers, which are obsolete and no longer available. There was a series built between 1960 and 1975 that used A1B branch breakers, which are also obsolete and no longer available.
The NA1B panelboard should be replaced by an NQ panelboard for 240VAC applications or DC applications up to 48VDC. In rare DC applications up to 250VDC replace with an I-Line panelboard.