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Maximum load on relay


#1

I need to connect 6 devices to 6 relays whose load varies from 500 watts to 1500 watts. Can I use 16x Board with Panda II (because on board is given a maximum load of 600 watts)?
Having the need to overcome the 16 relays can be connected to more than one Board 16x Really Panda II?
Thanks


#2

What also matters is, is it AC or DC? Is it a resistive load(like lights) or inductive load(like motors)?


#3

When sizing a relay to a particular job ‘Watts’ is not a very useful metric.

The most important specifications are:

  1. Voltage rating
  2. Current rating (AC and/or DC)
  3. Type of load

The brochure on the 16x board say the relays are rated at 5A, since there is no other specification given we don’t know the voltage rating (I suspect it is 220VAC). Your largest load is 1500W which at 220V is about 7A, or 14A at 110V. So these relays would not switch your load, nor would the traces on the board likely be of sufficient size. I would also caution against trying to use two relays in parallel, this will not work as one set of contacts will always make contact first and bear the brunt of the surge current.

The DC load rating of a relay is usually much lower than AC. Also, highly inductive loads like motors can have a starting current 2-3 times their running current.

You might be able to use the 16x relays to control larger relays or a contactor for your larger loads though.


#4

Yes, are motors AC.


#5

I think it is best to use for each load (motor) its own relay.
Thanks for your cooperation.