NEMA contact ratings

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NEMA contact ratings are how much current at a rated voltage a relay or other pilot device can switch. The current rating of smaller NEMA contactors or their auxiliaries are defined by NEMA ICS 5: Industrial Control and Systems, Control Circuit and Pilot Devices[1] standard. The nomenclature is a letter followed by a three digit number, the letter designates the current rating of the contacts and the current type (i.e., AC or DC) and the number designates the maximum voltage design values.

AC Contact Ratings[edit]

Contact Rating Designation Thermal Current Voltage
A150 10 150
A300 10 300
A600 10 600
B150 5 150
B300 5 300
B600 5 600
C150 2.5 150
C300 2.5 300
C600 2.5 600
D150 1 150
D300 1 300
E150 0.5 150

DC Contact Ratings[edit]

Contact Rating Designation Thermal Current Voltage Voltamperes
N150 10 150 275
N300 10 300 275
N600 10 600 275
P150 5 150 138
P300 5 300 138
P600 5 600 138
Q150 2.5 150
Q300 2.5 300
Q600 2.5 600
R150 1 150
R300 1 300

See also[edit]

Utilization categories

References[edit]

  1. ^ "NEMA ICS 5-2000 (R2005, R2010)". Retrieved 1 June 2012.