80459-641-01E Model 6 Motor Control Centers
10/2012 Section 12—Insulation Resistance
© 1999–2012 Schneider Electric All Rights Reserved
105
ENGLISH
Thermal Overload Unit Selection This section identifies the thermal overload units needed for the starters
specified in an order. Tables are based on motor full-load amps and provide
the catalog number for the appropriate thermal units to be used at that
current rating.
Melting Alloy Overload Selection Tables for Combination Starter Units
Size 1 Size 2
Motor
Full-Load
Current (A)
Thermal Unit
Number
Motor
Full-Load
Current (A)
Thermal Unit
Number
Motor
Full-Load
Current (A)
Thermal Unit
Number
Motor
Full-Load
Current (A)
Thermal Unit
Number
0.56–0.63 B 0.81 4.12–4.70 B 6.90 3.94–4.45 B 6.90 14.0–15.8 B 25
0.64–0.68 B 0.92 4.71–5.21 B 7.70 4.46–4.97 B 7.70 15.9–17.9 B 28
0.69–0.77 B 1.03 5.22–5.53 B 8.20 4.98–5.28 B 8.20 18.0–19.9 B 32
0.78–0.85 B 1.16 5.54–6.17 B 9.10 5.29–5.97 B 9.10 20.0–22.8 B 36
0.86–0.97 B 1.30 6.18–7.02 B 10.2 5.98–6.89 B 10.2 22.9–25.4 B 40
0.98–1.09 B 1.45 7.03–7.92 B 11.5 6.90–7.92 B 11.5 25.5–28.9 B 45
1.10–1.21 B 1.67 7.93–8.61 B 12.8 7.93–8.71 B 12.8 29.0–30.8 B 50
1.22–1.33 B 1.88 8.62–9.17 B 14 8.72–9.27 B 14.0 30.9–32.5 B 56
1.34–1.53 B 2.10 9.18–10.0 B 15.5 9.28–10.2 B 15.5 32.6–34.9 B 62
1.54–1.73 B 2.40 10.1–11.0 B 17.5 10.3–11.4 B 17.5 35.0–39.7 B 70
1.74–1.89 B 2.65 11.1–11.8 B 19.5 11.5–12.3 B 19.5 39.8–44.7 B 79
1.90–2.17 B 3.00 11.9–13.5 B 22 12.4–13.9 B 22
2.18–2.53 B 3.30 13.6–15.3 B 25
2.54–2.87 B 3.70 15.4–17.4 B 28
2.88–3.22 B 4.15 17.5–19.4 B 32
3.23–3.49 B 4.85 19.5–22.2 B 36
3.50–3.85 B 5.50 22.3–25.1 B 40
3.86–4.11 B 6.25 25.2–27.0 B 45
Size 3 Size 4
Motor
Full-Load
Current (A)
Thermal Unit
Number
Motor
Full-Load
Current (A)
Thermal Unit
Number
Motor
Full-Load
Current (A)
Thermal Unit
Number
Motor
Full-Load
Current (A)
Thermal Unit
Number
14.0–14.9 CC 20.9 36.9–39.8 CC 59.4 44.0–46.8 CC 64.3 73.0–78.1 CC 112
15.0–16.2 CC 22.8 39.9–42.3 CC 64.3 46.9–50.6 CC 68.5 78.2–83.9 CC 121
16.3–17.2 CC 24.6 42.4–45.7 CC 68.5 50.7–54.5 CC 74.6 84.0–91.1 CC 132
17.3–18.7 CC 26.3 45.8–49.2 CC 74.6 54.6–58.4 CC 81.5 91.2–97.5 CC 143
18.8–20.2 CC 28.8 49.3–52.8 CC 81.5 58.5–62.9 CC 87.7 97.6–104 CC 156
20.3–21.7 CC 31.0 52.9–56.8 CC 87.7 63.0–67.7 CC 94.0 105–113 CC 167
21.8–23.3 CC 33.3 56.9–61.2 CC 94.0 67.8–72.9 CC 103 114–133 CC 180
23.4–25.2 CC 36.4 61.3–66.1 CC 103
25.3–27.1 CC 39.6 66.2–71.2 CC 112
27.2–29.4 CC 42.7 71.3–76.7 CC 121
29.5–31.6 CC 46.6 76.8–82.9 CC 132
31.7–34.0 CC 50.1 83.0–90.0 CC 143
34.1–36.8 CC 54.5