Need help deciphering the side label of a contactor or relay?


Today we are going to help decipher all the information that can be found on the side label on any contactor or relay.  To be hones there is a ton of information on there and most of it are electrical ratings.  We will explain each important section along with providing the common misconceptions as to what this information actual relates to.

1. IEC/EN and VDE - These are electrical category ratings used for Europe, the UK and North America.  They simply denote what type of electrical product it is and are not specific to any manufacturer or individual part.  Every contactor made on the market today with have a IEC/EN code of 60947, no matter if it is manufactured by Schneider, Eaton, Allen Bradley or Siemens.
  **Common misconception - despite being at the top of the label, this is not the part number.  It will not be specific to any part and does not help in determining what contactor is needed

2. Ith=32A - this is the thermal current rating for the contactor and that it can switch loads up to 32 AMPS AC-1.  It is important to note that this is the AC-1 rating, not the more common UL AC-3 rating.  AC-1 ratings are used for resistive loads.
  **Common misconception - This is not necessarily the AMP rating of the contactor.  The label to the left is for a 32 AMP AC-1, 18 AMP AC-3 and in 99% of all applications you will want to go by the AC-3 rating

3. kW and H.P. ratings - This charts shows the different kilowatt and horsepower ratings at different voltages for 3 Phase applications.  For example, this contactor is rated 5.5 H.P. @ 230 volt and 10 H.P. at 440 volt 3 Phase.
  **Common misconception - This is just a table for kW and H.P. ratings and has nothing to do with the coil or control voltage

4.  32A 600V - This rating is for the base mounted auxiliary contact block (usually terminals numbers 13/14 for normally open contacts and 21/22 for normally closed contacts) and has no bearing on the AMP rating or voltage of the contactor.  This is the maximum current that can be passed through this contact
  **Common misconception - This is not the AMP rating or voltage for the contactor, just the auxiliary contact that is on the contactor

5. H.P. ratings - This is the chart for single and three phase horsepower ratings for this contactor.  For example, this contactor is rated for 3 H.P. @ 230 volt single phase and it is also rated for 10 H.P. @ 460 volt three phase. 
  **Common misconception - these are just the H.P. ratings and have nothing to do with the line or control (coil) voltages for this contactor