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Can you operate a Parker 514C without using the AC Supply Contactor?

I have an installation where the AC supply is controlled by a contactor upstream of the 514C.  Is it still necessary to install another contactor like the one in Chapter 2 of the manual "Basic Wiring"?  If so why?  

  • Hello John,

    The 514C doesn't care either way, even about the single contactor.  Those are recommendations for your system, nothing more.  Having a contactor to control the AC supply is a good ideal for safety purposes if nothing else, so you can turn it off if you need to service the drive or make wiring changes or even if someone is just working on the machine and you want to ensure the drive can't get power and thus possible make a move.

    If your upstream contactor is simply being shared by multiple devices, that is fine, unless you have need of having those devices under power while the 514C is not, then a secondary contactor would be useful.  

    The contactor is literally just a good recommendation towards safety.  The drive does not require it.  The fuses or circuit breakers are in this same category.  No required by the drive, but a very strong recommendation for safety.  These help protect from serious issues if the drive fails in some fashion, fusing/circuit breaker helps prevent more severe consequences.  These types of devices will be required if you are pursuing UL certification on your machine or system for sure.  

    The other optional feature regarding a contactor, is having the drive engage this contactor when you go into 'Run' mode and the drive is not in a fault/alarm condition.  This is what the A2/A2 terminal provide.  A way to energize the coil of the contactor when the Run signal is applied (since in that point you only have the AUX AC supply applied on A4/A3).  The Run signal also triggers that AUX output (A2/A1) which then close the main AC contactor which then applies the main AC supply and you are good to start running (but if the drive is in an alarm/fault state it won't trigger that AUX output and prevents the main AC supply from being applied to the drive).  

    All of these external devices like fusing, circuit breakers, AC contactors, etc.  are optional and up to what you need/want in your system.  However, they are highly recommended from a safety perspective.