Illustration 3.20 I7, I8 Enclosure
IP54, 380-480 V, 45-55 kW (60-70 HP)
IP54, 380-480 V, 75-90 kW (100-125 HP)
3.2.4
Fuses and Circuit Breakers
Branch circuit protection
To protect the installation against electrical and fire hazard,
all branch circuits in an installation, switch gear, machines
etc., must be short-circuit and overcurrent protected
according to national and local regulations.
Short circuit protection
Danfoss recommends using the fuses and circuit breakers
listed in Table 3.8 to protect service personnel or other
equipment in case of an internal failure in the unit or
short-circuit on DC-link. The frequency converter provides
full short circuit protection in case of a short-circuit on the
motor.
Overcurrent protection
Provide overload protection to avoid overheating of the
cables in the installation. Overcurrent protection must
always be carried out according to local and national
regulations. Circuit breakers and fuses must be designed
for protection in a circuit capable of supplying a maximum
of 100000 A
rms
(symmetrical), 480 V maximum.
UL/Non UL compliance
Use the circuit breakers or fuses listed in Table 3.8, to
ensure compliance with UL or IEC 61800-5-1.
Circuit breakers must be designed for protection in a
circuit capable of supplying a maximum of 10000 Arms
(symmetrical), 480 V maximum.
NOTICE
In the event of malfunction, failure to follow the
protection recommendation may result in damage to the
frequency converter.
Installation Quick Guide
MG18A602 Danfoss A/S © 08/2014 All rights reserved. 17
3 3