Control Circuit Classifications

NEMA and IEC control circuit classifications
AC-Control Circuit Classifications—NEMA
NEMA designates Control Circuit Rating with a
code letter (for current) and a voltage code.
Ratings & Test Values for AC Control Circuit Contacts at 50 or 60Hz
Thermal
Maximum Current, Amperes
Contact
Continuous
240 Volts
Rating
Test Current, 120 Volts
Designation Amperes
Make
Break
Make
A150
A300
A600
B150
B300
B600
C150
C300
C600
D150
D300
E150
10
10
10
5
5
5
2.5
2.5
2.5
1
1
0.5
60
60
60
30
30
30
15
15
15
3.6
3.6
1.8
6
6
6
3
3
3
1.5
1.5
1.5
0.6
0.6
0.3
480 Volts
Break
Make
—
3
3
—
1.5
1.5
—
0.75
0.75
—
0.3
—
—
—
15
—
—
7.5
—
—
3.75
—
—
—
—
30
30
—
15
15
—
7.5
7.5
—
1.8
—
600 Volts
Break
Voltamperes
Make
Break
Make
Break
—
—
12
—
—
6
—
—
3
—
—
—
—
—
1.2
—
—
0.6
—
—
0.3
—
—
—
7200
7200
7200
3600
3600
3600
1800
1800
1800
432
432
216
720
720
720
360
360
360
180
180
180
72
72
36
—
—
1.5
—
—
0.75
—
—
0.375
—
—
—
DC-Control Circuit Classifications—NEMA
Rating codes for DC Control Circuit Contacts
Contact
Rating
Designation1 )
Thermal
Continuous
Test Current,
Amperes
125 Volt
250 Volt
301 to 600 Volt
N150
N300
N600
P150
P300
P600
Q150
Q300
Q600
R150
R300
10
10
10
5
5
5
2.5
2.5
2.5
1
1
2.2
2.2
2.2
1.1
1.1
1.1
0.55
0.55
0.55
0.22
0.22
—
1.1
1.1
—
0.55
0.55
—
0.27
0.27
—
0.11
—
—
0.4
—
—
0.2
—
—
0.1
—
—
Maximum
Make or Break
Voltamperes
at 300 Volts or Less
Maximum Make or Break2 )
Current, Amperes
275
275
275
138
138
138
69
69
69
28
28
Control Circuit Classifications—IEC3 )
IEC 947-5-1 Uses Utilization Categories AC15 to Specify Control Circuit Ranges.
Current at each voltage is specified by the
manufacturer, not by the standard.
AC Control Circuit
Utilization
Categories
per IEC 947-5-1
Make
I/Ie
U/Ue
I/Ie
U/Ue
AC-12
AC-13
AC-14
AC-15
1
2
6
10
1
1
1
1
1
1
1
1
1
1
1
1
Break
DC Control Circuit
Utilization
Categories
per IEC 947-5-1
Make
I/Ie
U/Ue
I/Ie
U/Ue
DC-12
DC-13
DC-14
1
1
10
1
1
1
1
1
1
1
1
1
Break
Example of a Typical IEC Control Circuit Ratings Table4)
DC
AC
Ie /AC-12
(Continuous Amps)
Ue
AC Voltage
Ie /AC-15
Amps
Voltage
Ie /DC-12
Ie /DC-13
10
24V
110V
220/230V
380/440V
6A
6A
6A
4A
24
60
110
230
6A
5A
2.5A
1A
3A
1.5A
0.7A
0.3A
1)The numerical suffix designates the maximum voltage design values, which are to be 600, 300, and
150 volts for suffixes 600, 300, and 150 respectively.
Test voltage shall be 600, 250, or 125 volts. MLLDLL.
2)For maximum ratings at 300 volts or less, the maximum make and break ratings are to be obtained by
dividing the volt-ampere rating by the application
voltage, but the current value is not to exceed the
thermal continuous test current.
3) I e
Rated operational current
U e Rated operational voltage
I
Current to be made or broken
U
Voltage before make
4)Example: A control circuit contact having an AC-15
rating of 6 amps at 230 volts is capable of making 60
amps and breaking 6 amps at 230 volts. KRE.
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