22 VFD66 User Guide
www.johnsoncontrols.com Issue Number: 2
5.2 Altitude de-rating
See Table 5-1 for altitude multipliers. Use the following formula to determine the
adjusted rating:
Table 5-1 Altitude multipliers
Temperature De-Rated
Maximum Output Amperes
X
Altitude
Multiplier
=
De-Rated Maximum
Output Amperes
Altitude Range Altitude Multiplier
0-3300 ft (0-1000 m) 1.0
3300-4300 ft (1000-1305 m) 0.97
4300-5300 ft (1305-1610 m) 0.94
5300-6300 ft (1610-1915 m) 0.91
6300-7300 ft (1915-2220 m) 0.88
7300-8300 ft (2220-2525 m) 0.86
8300-9300 ft (2525-2830 m) 0.83
9300-9842 ft (2830-3000 m) 0.80