A 120/240 Volt service panel has the following loads connected to it: i) 240 V h

Question

A 120/240 Volt service panel has the following loads connected to it: i) 240 V heater that draws 7 amps ii) 120 V lighting circuit between hot line #1 and neutral drawing 2 Amps iii) 120 V lighting circuit between hot line #1 and neutral drawing 3 amps iv) 120 V control circuit between hot line #2 and neutral drawing 1 Amp v) 120 V heater circuit between hot line #2 and neutral drawing 5 Amps. If I was looking for combinations of the above load that would result in no current on the neutral, could I use loads ii) and iii) with v) ? Just load i) alone? Would there be any others?

Explanation / Answer

For the neutral wire to carry no current, all the loads (power) must be balanced. Power=Volts * Amperes So, for load i) : P=240 V * 7 A = 1680 W for load ii) : P=120 V * 2 A = 240 W for load iii) : P=120 V * 3 A = 360 W for load iv) : P=120 V * 1 A = 120 W for load v) : P=120 V * 5 A = 600 W If we choose load ii) and iii) its total power is (240+360=600) same as that of load v). So, the neutral wire here will carry no current as the power is balanced. If we choose just load i) alone, then also the neutral wire will have no current, as its circuit id not in contact with the neutral wire. In others, we can choose load ii) and iv) with load iii). As both the powers are balanced and equal to 360 W

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.