Environmental And Application-Specific Factors; Ambient Air Temperature Compensation And Derating - ABB MS116 Manual

4. Environmental and application-specific factors

Manual motor starters are suitable for use in many climates. They are intended for use in enclosed environments in
which no severe operating conditions (such as dust, caustic vapors or hazardous gases) prevail. When installed in
dusty and damp areas, suitable enclosures must be provided.

4.1 Ambient air temperature compensation and derating

Temperature compensation applies to bi-metallic devices which employ a secondary bi-metal to counteract the bi-
metals of the inverse time-delay overcurrent release. The secondary bi-metal is not heated by the motor current, in-
stead it reacts only under the influence of the ambient air temperature. As a result, the effects of the ambient
temperature in regard to manual motor starter tripping is automatically compensated for.
ABB manual motor starters have an allowable ambient temperature range for single mountings between -25°C to
60°C (50°C for MS116). Correction factors for ambient temperatures up to 70°C and for group mounting are shown
below.
Device
MS132-0.16 ... 4.0
MS132-6.3
MS132-10
MS132-12
MS132-16
MS132-20
MS132-25
MS132-32
Table 13: Ambient air temperature compensation and derating. Note: the temperature values between those shown can be linearly interpolated.
APR I L 19
MA N UA L MOTOR START ER G UI D E
Current correction factors for sin-
gle mounting, or group mounting
with spacing ≥ 9 mm
40°C 60°C
1.00 1.00
1.00 1.00
1.00 1.00
1.00 1.00
1.00 1.00
1.00 1.00
1.00 1.00
1.00 1.00
Current correction factors for
group mounting without spacing
1)
70°C 40°C
1.00 1.00
1.00 1.00
0.80 0.91
0.91 1.00
0.81 0.93
0.90 1.00
0.92 1.00
0.90 1.00
60°C 70°C
1.00 1.00
1.00 0.79
0.80 0.70
0.91 0.83
0.87 0.81
0.95 0.85
0.92 0.80
0.93 0.78
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