11.4.2 Derating for Altitude
The cooling capability of air is decreased at lower air pressure.
Below 1000 m altitude no derating is necessary but above 1000 m the ambient temperature (T
AMB
) or max. output current
(I
out
) should be derated in accordance with Illustration 11.7.
An alternative is to lower the ambient temperature at high altitudes and thereby ensure 100% output current at high
altitudes. As an example of how to read the graph, the situation at 2,000 m is elaborated. At a temperature of 45 °C (T
AMB,
MAX
- 3.3 K), 91% of the rated output current is available. At a temperature of 41.7 °C, 100% of the rated output current is
available.
80
0 500
100
95
90
85
1000 1500 2000 2500 3000
Altitude (meters above sea level)*
130BB008.10
I
OUT
(%)
Illustration 11.7 Altitude Derating
110
100
90
80
70
60
50
40
30
20
10
0
0 5 10 15 20 25 30 35 40 45 50 55
Tamb (Max) Deg C
Iout (%)
130BD937.10
Illustration 11.8 Input/Output vs. Maximum Ambient
Temperature
11.5 Fuses
Danfoss recommends using fuses and/or circuit breakers on the supply side as protection in case of component break-down
inside the frequency converter (first fault).
NOTICE
Using fuses and/or circuit breakers ensures compliance with IEC 60364 for CE or NEC 2009 for UL.
Branch Circuit Protection
To protect the installation against electrical and fire hazard,
all branch circuits in an installation, switch gear, machines
etc., must be protected against short-circuit and over-
current according to national/international regulations.
NOTICE
The recommendations do not cover branch circuit protection for UL.
Short-circuit protection
Danfoss recommends using the fuses/circuit breakers in chapter 11.5.2 Fuse Tables to protect service personnel and property
in case of component break-down in the frequency converter.
11.5.1 Non UL compliance
Non UL compliance
If UL/cUL is not to be complied with, Danfoss recommends
using the following fuses, which ensures compliance with
EN50178:
P132-P200 380-500 V type gG
P250-P400 380-500 V type gR
Table 11.5 Recommended Fuses for non-UL Applications
Specifications Operating Instructions
MG37A202 Danfoss A/S © Rev. 2014-07-29 All rights reserved. 153
11 11
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