UL Sizing Chart (1 Phase) HP
Volts
1/10 1/8 1/6 1/4 1/3 1/2 3/4 1 1 1/2 2 3 5 7 1/2 10 15
120 230 120 230 120 230 120 230 120 230 120 230 120 230 120 230 120 230 120 230 120 230 120 230 120 230 120 230 120 230
Cerus Motor Overload
Bend Motor Wire Size Radius* Amps (AWG) (Inches)
Contactor
3.0 1.5 3.8 1.9 4.4 2.2 5.8 2.9 7.2 3.6 9.8 4.9 13.8 6.9 16.0 8.0 20.0 10.0 24.0 12.0 34.0 17.0 56.0 28.0 80.0 40.0 100.0 50.0 135.0 68.0
MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-12 MRC-9 MRC-18 MRC-9 MRC-18 MRC-9 MRC-25 MRC-12 MRC-25 MRC-18 MRC-40 MRC-18 MRC-63 MRC-32 MRC-85 MRC-40 CRC-100 MRC-63 CRC-150 CRC-75
12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 10 12 8 12 6 10 4 8 3 8 1/0 4
1.5 2 3 1.5 3 1.5 5 2
Thermal MTK-32/3-4 MTK-32/3-1.6 MTK-32/3-4 MTK-32/3-2.5 MTK-32/3-6 MTK-32/3-2.5 MTK-32/3-8 MTK-32/3-4 MTK-32/3-8 MTK-32/3-4 MTK-32/3-13 MTK-32/3-6 MTK-32/3-18 MTK-32/3-8 MTK-32/3-18 MTK-32/3-9 MTK-32/3-25 MTK-32/3-13 MTK-32/3-25 MTK-32/3-13 MTK-63/3-40 MTK-32/3-22 MTK-63/3-65 MTK-32/3-32 MTK-95/3-85 MTK-63/3-50 CTK-100/3-125A MTK-63/3-65 CTK-150/3-150 CTK-85/3-75
Electronic
Manual Motor Starter
Motor Circuit Protector
CRP22-3P 5A CRP22-3P 5A CRP22-3P 5A CRP22-3P 5A CRP22-3P 5A CRP22-3P 5A CRP22-3S 22A CRP22-3P 5A CRP22-3S 22A CRP22-3P 5A CRP22-3S 22A CRP22-3S 22A CRP22-3S 22A CRP22-3S 22A CRP22-3S 22A CRP22-3S 22A CRP22-3S 22A CRP22-3S 22A CRP40-3S 40A CRP22-3S 22A CRP40-3S 40A CRP22-3S 22A CRP80-3S 80A CRP40-3S 40A CRP80-3S 80A CRP80-3S 80A CRP80-3S-80A
CMS-32HI-4 CMS-32HI-1.6 CMS-32HI-4 CMS-32HI-2.5 CMS-32HI-6 CMS-32HI-2.5 CMS-32HI-8 CMS-32HI-4 CMS-32HI-8 CMS-32HI-4 CMS-32HI-13 CMS-32HI-6 CMS-32HI-17 CMS-32HI-8 CMS-32HI-17 CMS-32HI-10 CMS-32HI-22 CMS-32HI-13 CMS-32HI-26 CMS-32HI-13 CMS-63HI-40 CMS-32HI-22 CMS-63HI-63 CMS-32HI-32 CMS-100HI-90 CMS-63HI-50 CMS-63HI-63 CMS-100H-75
CMS-32HI-4 CMS-32HI-1.6 CMS-32HI-4 CMS-32HI-2.5 CMS-32HI-6 CMS-32HI-2.5 CMS-32HI-6 CMS-32HI-4 CMS-32HI-8 CMS-32HI-4 CMS-32HI-10 CMS-32HI-6 CMS-32HI-17 CMS-32HI-8 CMS-32HI-17 CMS-32HI-8 CMS-32HI-22 CMS-32HI-10 CMS-32HI-26 CMS-32HI-13 CMS-63HI-40 CMS-32HI-17 CMS-63HI-63 CMS-32HI-32 CMS-100HI-90 CMS-63HI-40 CMS-100HI-100 CMS-63HI-50 CMS-100HI-75
Motor Engineering Formulas Legend E = Volts I = Amps W = Watts PF = Power Factor Eff = Efficiency HP = Horsepower 1HP = 746 Watts
AC/DC Formulas Single Phase
Three Phase
Amps when HP is known
To Find
HP x 746 E x Eff
HP x 746 E x Eff x PF
HP x 746 1.73 x E x Eff x PF
Amps when kW is known
kW x 1000 E
kW x 1000 E x PF
kW x 1000 1.73 x E x PF
Amps when kVA is known
-
kVA x 1000 E
kVA x 1000 1.73 x E
ExI
IxE 1000
I x E x PF 1000
I x E x 1.73 x PF 1000
P R
-
IxE 1000
I x E x 1.73 1000
I x E x Eff 746
I x E x Eff x PF 746
I x E x Eff x 1.73 x PF 746
Kilowatts Kilovolt (Amps) Horsepower (Output)
AC Efficiency & Power Factor Formulas To Find Efficiency Power Factor
Single Phase
Three Phase
746 x HP E x I x PF
746 x HP E x I x PF x 1.732
Input Watts VxA
Input Watts E x I x PF x 1.732
www.cerusind.com 1.800.962.3787
Ohm’s Law E2 I2 x R R
P E
IxR
P I
P E I R E R
P I2
PxR
E2 P
E I
Motor Application Formulas Horsepower = Torque (lb-ft) x RPM 5252 Torque (lb-ft) = Horsepower x 5252 RPM
UL Sizing Chart (3 Phase) HP
1/2
3/4
1
1 1/2
2
3
5
7 1/2
10
15
20
25
30
40
50
60
75
100
125
150
Volts 208 230 480 208 230 480 208 230 480 208 230 480 208 230 480 208 230 480 208 230 480 208 230 480 208 230 480 208 230 480 208 230 480 208 230 480 208 230 480 208 230 480 208 230 480 208 230 480 208 230 480 208 230 480 208 230 480 208 230 480
Bend Motor Wire Size Radius Amps (AWG) (Inches) 2.4 2.2 1.1 3.5 3.2 1.6 4.6 4.2 2.1 6.6 6.0 3.0 7.5 6.8 3.4 10.5 9.6 4.8 16.7 15.2 7.6 24.0 22.0 11.0 31.0 28.0 14.0 46.0 42.0 21.0 59.0 54.0 27.0 75.0 68.0 34.0 88.0 80.0 40.0 114.4 104.0 52.0 143.0 130.0 65.0 169.4 154.0 77.0 211.2 192.0 96.0 272.8 248.0 124.0 343.2 312.0 156.0 396.0 360.0 180.0
12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 10 10 12 8 10 12 8 8 10 6 6 10 4 4 8 3 4 8 2 2 6 1/0 1 6 2/0 2/0 4 4/0 3/0 3 2 x 1/0 2 x 1/0 1 2 x 2/0 2 x 2/0 2/0 2 x 3/0 2 x 3/0 3/0
* Field wiring requires two conductors
1.5 1.5 1.5 1.5 2 2 2 2 1.5 2.5 2 1.5 5 3 1.5 7 6 2 7 7 2 10 8 3 12 12 6 14 14 7 8* 7* 7
Cerus Motor Overload Contactor MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-9 MRC-12 MRC-12 MRC-9 MRC-18 MRC-18 MRC-9 MRC-25 MRC-25 MRC-12 MRC-35 MRC-32 MRC-18 MRC-50 MRC-50 MRC-25 MRC-63 MRC-63 MRC-32 MRC-75 MRC-75 MRC-35 MRC-95 MRC-85 MRC-50 CRC-125 CRC-125 MRC-63 CRC-180 CRC-150 MRC-75 CRC-180 CRC-180 MRC-85 CRC-300 CRC-220 CRC-125 CRC-300 CRC-300 CRC-150 CRC-400 CRC-400 CRC-180 CRC-600 CRC-400 CRC-220
Thermal MTK-32/3-2.5 MTK-32/3-2.5 MTK-32/3-1.6 MTK-32/3-4 MTK-32/3-4 MTK-32/3-1.6 MTK-32/3-6 MTK-32/3-6 MTK-32/3-2.5 MTK-32/3-8 MTK-32/3-8 MTK-32/3-4 MTK-32/3-9 MTK-32/3-9 MTK-32/3-4 MTK-32/3-13 MTK-32/3-13 MTK-32/3-6 MTK-32/3-18 MTK-32/3-18 MTK-32/3-9 MTK-32/3-25 MTK-32/3-25 MTK-32/3-13 MTK-63/3-36 MTK-32/3-32 MTK-32/3-18 MTK-63/3-50 MTK-63/3-50 MTK-32/3-25 MTK-63/3-65 MTK-63/3-65 MTK-32/3-32 MTK-95/3-85 MTK-95/3-75 MTK-63/3-40 MTK-95/3-95 MTK-95/3-85 MTK-63/3-50 CTK-100/3-125A CTK-100/3-125A MTK-63/3-65 CTK-220/3-180A CTK-150/3-150A MTK-95/3-75 CTK-220/3-180A CTK-220/3-180A MTK-95/3-85 CTK-400/3-240A CTK-220/3-240A CTK-100/3-125A CTK-400/3-300A CTK-400/3-300A CTK-150/3-150A CTK-400/3-400A CTK-400/3-400A CTK-220/3-180A CTK-600/3-400A CTK-400/3-400A CTK-220/3-240A
Electronic
Manual Motor Starter
Motor Circuit Protector*
CRP22-3P 5A CRP22-3P 5A CRP22-3S 1.5A CRP22-3P 5A CRP22-3P 5A CRP22-3P 5A CRP22-3P 5A CRP22-3P 5A CRP22-3P 5A CRP22-3S 22A CRP22-3S 22A CRP22-3P 5A CRP22-3S 22A CRP22-3S 22A CRP22-3P 5A CRP22-3S 22A CRP22-3S 22A CRP22-3P 5A CRP22-3S 22A CRP22-3S 22A CRP22-3S 22A CRP40-3S 40A CRP40-3S 40A CRP22-3S 22A CRP40-3S 40A CRP40-3S 40A CRP22-3S 22A CRP80-3S 80A CRP80-3S 80A CRP40-3S 40A CRP80-3S 80A CRP80-3S 80A CRP40-3S 40A CRP80-3S 80A CRP80-3S 80A CRP40-3S 40A CRP80-3S 80A CRP80-3S 80A CRP80-3S 80A CRP80-3S 80A -
CMS-32HI-2.5 CMS-32HI-2.5 CMS-32HI-1.6 CMS-32HI-4 CMS-32HI-4 CMS-32HI-1.6 CMS-32HI-6 CMS-32HI-6 CMS-32HI-2.5 CMS-32HI-8 CMS-32HI-8 CMS-32HI-4 CMS-32HI-8 CMS-32HI-8 CMS-32HI-4 CMS-32HI-13 CMS-32HI-13 CMS-32HI-6 CMS-32HI-22 CMS-32HI-17 CMS-32HI-10 CMS-32HI-26 CMS-32HI-26 CMS-32HI-13 CMS-63HI-40 CMS-32HI-32 CMS-63HI-50 CMS-63HI-50 CMS-32HI-26 CMS-63HI-63 CMS-63HI-63 CMS-32HI-32 CMS-100HI-90 CMS-100HI-75 CMS-63HI-40 CMS-100HI-100 CMS-100HI-90 CMS-63HI-50 CMS-63S/H-50 CMS-63HI-63 CMS-100HI-75 CMS-100HI-90 CMS-100HI-100 -
CMS-32HI-2.5 CMS-32HI-2.5 CMS-32HI-1.6 CMS-32HI-4 CMS-32HI-4 CMS-32HI-1.6 CMS-32HI-6 CMS-32HI-6 CMS-32HI-2.5 CMS-32HI-8 CMS-32HI-8 CMS-32HI-4 CMS-32HI-8 CMS-32HI-8 CMS-32HI-4 CMS-32HI-13 CMS-32HI-10 CMS-32HI-6 CMS-32HI-22 CMS-32HI-17 CMS-32HI-8 CMS-32HI-26 CMS-32HI-26 CMS-32HI-13 CMS-63HI-40 CMS-32HI-32 CMS-32HI-17 CMS-63HI-50 CMS-63HI-50 CMS-32HI-26 CMS-63HI-63 CMS-63HI-63 CMS-32HI-32 CMS-100HI-90 CMS-100HI-75 CMS-63HI-40 CMS-100HI-100 CMS-100HI-90 CMS-63HI-50 TS250NU ATU 250 250A TS250NU ATU 250 250A CMS-63HI-63 TS400NU ATU 400 400A TS400NU ATU 400 300A CMS-100HI-75 TS400NU ATU 400 400A TS400NU ATU 400 400A CMS-100HI-90 TS800NU ATU 800 500A TS800NU ATU 800 500A CMS-100HI-100 TS800NU ATU 800 600A TS400NU ATU 400 300A TS800NU ATU 800 800A TS800NU ATU 800 800A TS400NU ATU 400 400A TS400NU ATU 400 400A