FUSIBLES ELEMSA

All of ELEMSA’s links provide an effective protection against overcurrent for equipment and electric distribution systems.

They can also be combined with other protection devices to isolate feeder lines that present a malfunction.

A fuse is selected depending of its speed, measured as the relation of currents at 0.1 and 300 seconds, the higher the ratio, the less fusion speed.

FRACTIONAL FUSE (F TYPE)

In order to satisfy the special protection requirements from the new energy distribution schemes, the Fractional Fuse links.

They all have a nominal capacity remarkably close to the nominal continuous current that get the charge from small sized distribution builders, and are designed to protect from overloads and unnecessary operation during short periods.

Preferable nominal currents: 1/3, 1/2, 3/4, 1 1/4, 1 1/2, 2 1/2, 2 3/4 y 3 1/2 amperes.

TRANSFORMERS PROTECTION

 

FACTORS TO BE CONSIDERED

• Electrically isolate the transformer.
• Avoid internal failure that could cause the transformer destruction.
• Protect the transformer from severe overloads.
• Resist short lapse overloads./li>
• Resist cold charge currents and magnetization in the transformer.
• Resist surge damage caused by atmospheric discharge.
• Coordinate with other protective devices against overcurrents.

TRANSFORMER NOMINAL CURRENT SELECTION CRITERIA

• The fuse current must be stronger or equal to the transformer’s nominal current.
• The minimal current-time fusion curve must be at the right side of the transformer’s magnetization curve.
• The minimal current-time fusion curve must be at the right side of the transformer’s cold charge curve.
• The maximum current-time fusion curve must be at the left side of the transformer’s thermal bath.
• Selectively coordinate with other protection devices against overcurrents.

FUSSION SPEED

The fussion speed relationship between all 100 AMPS capacities and less is the relationship in the fussion current of 0.1 seconds and the fussion current of 300 seconds.

Fuse current at 300 seconds.

Minimal current fusion curve is approximately of a 170 range from the nominal current and provides a desirable overload capacity.

FUSSION CURRENT AT 0.1 SECONDS

Has a 3 AMPS range for the 0.33 AMPS fuse: up to 509 AMPS in the 15 AMPS fuse. This results in a high interruption capacity at all ranges.

ELEMSA’s Fractional Fuses is designed for self-impulse charges, recommended as primary transformer fuses for protection against short circuits and overcurrents.

ELEMSA’s CODE

The chart’s code is represented as indicated below:

• KV Nominal Tension = 15,27 and 38 for CFE
• KV Nominal Tension = 6 and 23 for LFC
• (Type) Fussion speed relation = K (fast) T (slow) F (fraction)
• Amperes Nominal Current = range from 0.33 A to 200 A.