Code Change Summary: Code language expanded regarding restricted access circuit breakers.
Many circuit breakers have adjustable trip settings to alter the circuit breaker trip curves to selectively coordinate with other devices. These settings should not be modified other than by qualified persons who are familiar with the system design.
In the past, adjustable circuit breaker settings required restricted access by measures such as removable and sealable covers over the adjusting means, or bolted equipment enclosure doors, or installation behind locked doors accessible only to qualified personnel.
In the 2020 NEC®, password protection, with a password accessible only to qualified personnel was added. Circuit breakers with newer electronic trip units provide the ability to require a password to keep unauthorized users from changing the settings.
Below is a preview of the NEC®. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2020 NEC® edition of NFPA 70.
2017 Code Language:
240.6(C) Restricted Access Adjustable-Trip Circuit Breakers. A circuit breaker(s) that has restricted access to the adjusting means shall be permitted to have an ampere rating(s) that is equal to the adjusted current setting (long-time pickup setting). Restricted access shall be defined as located behind one of the following:
(1) Removable and sealable covers over the adjusting means
(2) Bolted equipment enclosure doors
(3) Locked doors accessible only to qualified personnel.
2020 Code Language:
240.6(C) Restricted Access Adjustable-Trip Circuit Breakers. A circuit breaker(s) that has restricted access to the adjusting means shall be permitted to have an ampere rating(s) that is equal to the adjusted current setting (long-time pickup setting). Restricted access shall be achieved by one of the following methods:
(1) Located behind removable and sealable covers over the adjusting means
(2) Located behind bolted equipment enclosure doors
(3) Located behind locked doors accessible only to qualified personnel
(4) Password protected, with password accessible only to qualified personnel.
For adjustable trip circuit breakers, which of the following is true?
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