# Saving Money

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#### JohnJ0906

##### Senior Member
brian john said:
So that 4/0 I ran for all my branch circuit wiring was a waste, cost me a fortune just to termination.

No, not a waste, it will just take 64 years to pay for itself....

#### LarryFine

##### Master Electrician Electric Contractor Richmond VA
iwire said:
For the same amount of work produced, all other factors remaining unchanged larger conductors = less energy costs.
I agree 100% with this. Where we diverge is where the "more voltage means less current" discussions have disagreements. Most electrical equipment is not 'constant power'.

If the equipment is altered in some way, either electrically (voltage settings) or in its use (run longer), to adjust or compensate for a voltage difference, then higher voltage = less current, because the power consumed by the load is the same.

However, in the 'real world', when we're talking about a voltage drop, but the equipment is not adjusted for it, the power does not remain constant; more voltage drop means lower current (motors aside), and thus less total power.

Again, I agree that, for a constant power, any loss is power paid for but not used, but for most electrical equipment, the impedance does not change as terminal voltage sags, so the power varies with the current.

#### LarryFine

##### Master Electrician Electric Contractor Richmond VA
iwire said:
For the same amount of work produced, all other factors remaining unchanged larger conductors = less energy costs.
Right, it's just that the same amount of work is not produced as total circuit impedance, thus circuit current, thus terminal voltage varies. The load does not produce the same amount of power as its terminal voltage varies.

If electric heat runs long enough to satisfy the thermostat, then over time, the power produced, and thus the 'BTU's per hour' heat gain is the same, regardless of voltage drop. The KWh consumption, excluding waste, does not vary. The heat loss must be met with heat gain.

However, with a given load impedance, such as incandescent lighting, where the use pattern is not changed to compensate for voltage drop, the story is a bit different. We're not likely to leave a light on 10% longer to compensate for it being 10% dimmer.

#### bbaumer

##### Senior Member
LarryFine said:
You gotta consider the source of the information.

Smart man here.

Gonna have to do some number crunching myself. Seems hard to believe. Especially the #12 to #10 payback being only a matter of months.

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