A homeowner is installing a swimming pool. You have been asked to install a circuit to operate a 600-watt underwater light and a circulating pump. The motor nameplate reveals that the pump has a current draw of 8.5 amperes. The devices are considered continuous duty. Can the power to operate both of these devices be supplied by a single 20-ampere circuit?

The answer is given below

Step-by-step explanation:

The loads in the circuit are continuous duty, so the circuit can only loaded to 80% of its current rating.

Calculate 80% current rating of the circuit breaker.

Icb = [ 80/100] (20 A)

     =  (O.8) (20 A )

     = 16 A

Now we assume that the value of supply voltage is 120 V

Now we will calculate current flows via under water light which will be taken as  Load 1

Ii = 500 W/120 V

  = 4.167 A

Current via the circulating pump which will be taken as Load 2 IS 8.5 A

I = load1 + load 2

   = 4.167 A + 8.5 A

  = 12.67 A

The total current in the circuit obtained which is less than the circuit breaker rating current. Therefore, the power can be operated for both the loads.