Primary Fuse Sizing Chart - Refer to NEC Requirements Only (When Primary and Secondary Protection is used.) Maximum Ampere Rating for Current Limiting Class CC Fuses based on Transformer Primary Voltage. ATTENTION: To prevent electrical shock, disconnect from power source before installing or servicing.

fuses for the protection of the motor control circuits in accordance within the National Electrical Code®. Apply fuses per Table 1 for control circuit without a control transformer (see Circuit Diagrams 1 and 2). Apply fuses per Table 2 for a control circuit with a control transformer (see Circuit Diagrams 3 and 4). Motor Control Circuit ...

To assist in the selection of fuses, the following chart recommends the maximum primary fuse rating in amperes. The first number shown is the maximum overcurrent protection when the primary current is less than 2 amps and the overcurrent

Consult fixture manufacturer for size and type. Protected by Time-Delay Fuses. 250% to 300% of Full Load Current. Non-Time-Delay Fuses. Protection recommended as shown, but not required. Overcurrent Device. Size at 125% or next size larger but in no case larger than 60 amps for each subdivided load.

2008年6月24日 · Use TransCalc to easily and quickly size the fuses as well as the CPTs themselves. Read the guideline below for manually sizing fuses. If the rated primary current of the transformer is less than 2 amps, the maximum rating of …

Control circuit transformers (CCTs) are used to provide a reduced voltage for control circuits in motor control center (MCC) units. CCTs require primary protection per the National Electrical Code (Article 430-72[c]) and UL Safety Standard 845.

Bulletin 1497 Global Control Circuit Transformers are designed to reduce supply voltages to control circuits. The complete line of transformers is available with optional factory-installed or panel-mount primary and secondary fuse block.

To assist in the selection of fuses, the following chart recommends the maximum primary fuse rating, in amperes. The first number shown is the maximum overcurrent protection when the primary current is less than 2 amps and the overcurrent protection device is rated for 300%.

To select the proper fuses for your control power transformer, apply the following steps to the primary and secondary fuse sizing tables below: Determine if your application is a power circuit or a motor circuit, and refer to the corresponding primary fuse sizing table

You should use Class CC fuses on the primary, and midget fuses on the transformer secondary. This applies to the 1497, the 1497A, and the 1497B transformers. See the Control Circuit Transformers Selection and Technical Data Guide publication …