Part of the legacy EF series, the Siemens REF3B070 delivers 70A of thermal-magnetic protection for commercial and industrial facilities. It secures aging infrastructure against overcurrents and short circuits. This 3-pole breaker bolts securely into older Siemens or I-T-E panelboards and switchboards. When upgrading, the ED63B070 serves as the modern replacement. It handles up to 14 kAIC at 480VAC and accepts 14-1/0 AWG copper wiring.
Is the Siemens EF3B070 a current production model?
The EF3B070 is a legacy E-frame circuit breaker originally produced by ITE and Siemens. When replacing this unit, the newer ED-frame series, such as the ED63B070, is commonly used as a modern equivalent for 600V applications.
What panels accept the EF3B070 circuit breaker?
This breaker is compatible with legacy Siemens and ITE panelboards and switchboards designed to accept E-frame bolt-on breakers. It is not compatible with standard plug-on load centers.
Does this breaker mount to a standard DIN rail?
No, the EF3B070 is a bolt-on molded case circuit breaker. It must be bolted directly to the busbars inside a compatible industrial panelboard or switchboard.
Can the EF3B070 be utilized in DC electrical systems?
Yes, the thermal-magnetic trip unit is rated for direct current applications up to 250VDC, allowing it to be used in industrial DC control panels or battery systems.
Do I need to purchase separate lugs for the load side?
No, the breaker includes factory-installed load-side mechanical lugs. These terminals are dual-rated for both copper and aluminum conductors.
Can the trip settings on the EF3B070 be adjusted in the field?
No, this breaker features a fixed thermal and fixed magnetic trip unit. The long-time and instantaneous trip functions are factory calibrated and cannot be modified by the user.
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