1. Regulations
  2. title 46
  3. chapter I-i3
  4. part 111
  5. subpart 111.20
  6. § 111.20-5

View all text of Subpart 111.20 [§ 111.20-1 - § 111.20-15]

§ 111.20-5 - Temperature rise.

(a) The temperature rise, based on an ambient temperature of 40 degrees C, must not exceed the following:

(1) For Class A insulation, 55 degrees C.

(2) For Class B insulation, 80 degrees C.

(3) For Class F insulation, 115 degrees C.

(4) For Class H insulation, 150 degrees C.

(b) If the ambient temperature is higher than 40 degrees C, the transformer must be derated so that the total temperature stated in this section is not exceeded. The temperature must be taken by the resistance method.

AUTHORITY: 46 U.S.C. 3306, 3703; DHS Delegation No. 00170.1, Revision No. 01.2. Section 111.05-20 and Subpart 111.106 also issued under sec. 617, Pub. L. 111-281, 124 Stat. 2905.

SOURCE: CGD 74-125A, 47 FR 15236, Apr. 8, 1982, unless otherwise noted.

CITE AS: 46 CFR 111.20-5