Calculating max load for relay

[sairfan1]

Hi,

I'm building some circuits for home automation where I'm using general relay module available at eBay or Aliexpress, there is mentioned 10A 125V AC on it, i want to know how can i calculate safe load for it for example if want to turn on/off 1000/1500W 110V heater from this.
thanks.

 

[Audioguru]

10A at 125V is 1250W. The relay is overloaded with your 1500W heater. The 1500W heater might use 1636W if your voltage is actually 120V. My voltage at home is always 121V.

 

[D.A.(Tony)Stewart]

Songle SRD series specs indicate aging effects of current on switch life.

It will work for a while but 15A rating is needed for reliability.

 

[sairfan1]

thanks, i want to learn such thing so that in future i can calculate myself life and safe load for relay.

so what i understand we can calculate load 125V 10A so 125x10 = 1,250 so total load can be 1,250W
2nd and very important thing is to consider life expectancy,

 

[Kfir Maymon]

power = voltage * current, for the reliability i take 5 or 10 present insurance,
10 amp * 125 volt = 1250 Watt i would use max 1250 * 90%= 1125 Watt.