Issue:
Fuse Sizing
Resolution:
Fuses, disconnects and circuit breakers installed at the factory are sized between the range of 150-225% RLA. The smallest fuse that falls in this range is installed. The maximum fuse size allowed is the largest available without going over the maximum overcurrent protection (225% RLA).
The smallest fuse that will not trip during normal operation provides the most protection, however this may allow an intermittent trip due to high ambient temperatures or extreme operating conditions. Fuse sizing is a compromise at best and the maximum fuse isn't always the right answer.
Notes:
Maximum fuse size is the maximum that is allowed by the National Electric Code. Do not install a fuse size any bigger. Recommended fuse size allows selection of a smaller, less expensive fuse than maximum size and still allows for adequate protection.
Changes:
Other Question/Problem/Cause Statements:
- Fuse Sizing
Facts:
- RTAA 70-125 Ton (Pueblo)
- RTAC
- RTHD
- RTUA
- RTWA
- Air-Cooled Chiller (Pueblo) (RTAA 70-125 Ton)
- Air-Cooled Chiller (Pueblo) (RTAC)
- Compressor Chiller (Pueblo) (RTUA)
- Water-Cooled Chiller (Pueblo) (RTHD)
- Water-Cooled Chiller (Pueblo) (RTWA)
- Air-Cooled Chiller (Charmes) (RTAD)
- Air-Cooled Chiller (Pueblo) (CGAM 20-130 Ton)
- Air-Cooled Chiller (Pueblo) (RTAE)
- Compressor Chiller (Pueblo) (RTUD 70-200 Ton)
- Water-Cooled Chiller (Pueblo) (RTWD)
Document Identifier: DOC-76103
Document Identifier: 76103
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.