Thiết bị & Hệ thốngCâu 261 / 521
If a motor-compressor (rated-load 18 A) will not start on the 175% device, NEC 440.22(A) permits increasing the protection to a maximum of what value?
a.225% = 40.5 A
b.200% = 36 A
c.250% = 45 A
d.300% = 54 A
Giải thích
NEC 440.22(A) allows an increase up to 225% of the rated-load current where the 175% device will not carry starting current: 18 x 2.25 = 40.5 A. 200%, 250%, and 300% are not the permitted ceilings for hermetic-compressor branch-circuit protection.
Trích dẫn luật: 2023 NEC §440.22Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
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