We are installing a Fire Protection System (Diesel engine) and the pressure maintenance (jockey) motor is electric motor, as covered in 695.4 (B) (2) (a). Will the JOCKEY motor overcurrent device carry the locked rotor current ?
Please reference code/documentation that can be used to support any answers.
THANK YOU for your help !!!
Jonh
Hello Ron
"The 2014 NEC has made some clarifications in part (B) as to what is not covered in the article. The installation of pressure-maintenance (jockey) pumps (as distinguished from how their existence may need to be factored into the fire-pump electrical installation should they be present) is not covered in Art. 695."
Thank You
In addition, in section 695.4 (B) (2) (a) (1) it mentions the selection of the type of protection for these pumps, as a criterion of continuity of electrical power and dimensioning an overcurrent device to transport indefinitely the current of locked rotor and even system controllers.
John.
695.1(B)(1) excludes the installation of pressure maintenance pumps from the scope of Article 695. The branch-circuit short-circuit and ground-fault protective device(s) for this equipment must be sized in accordance with Part IV of Article 430. For an inverse time circuit breaker protecting a three-phase motor, the maximum rating is 250% of the value obtained from Table 430.250 based on the voltage and horsepower rating of the motor.