In order to protect the installation against electrical and fire hazard, all branch circuits in an installation, switch gear, machines etc., must be short-circuited

and over-current protected according to national/international regulations.

Short-circuit protection:

The frequency converter must be protected against short-circuit to avoid electrical or fire hazard. Danfoss recommends using the fuses mentioned below

to protect service personnel and equipment in case of an internal failure in the drive. The frequency converter provides full short-circuit protection in case

of a short-circuit on the motor output.

Over-current protection

Provide overload protection to avoid fire hazard due to overheating of the cables in the installation. The frequency converter is equipped with an internal

over-current protection that can be used for upstream overload protection (UL-applications excluded). See par. 4-18

circuit breakers can be used to provide the over-current protection in the installation. Over-current protection must always be carried out according to

national regulations.

Non UL compliance

If UL/cUL is not to be complied with, we recommend using the following fuses, which will ensure compliance with EN50178:

P110 - P250

P315 - P450

380-480 V, frame size D

The fuses below are suitable for use on a circuit capable of delivering 100,000 Arms (symmetrical), 240V, or 480V, or 500V, or 600V depending on the

drive voltage rating. With the proper fusing the drive Short Circuit Current Rating (SCCR) is 100,000 Arms.

Bussmann

Size/

E1958

E4273