View Full Version : Line voltage standards

12-17-2007, 11:38 AM
I heard a cranky old talk show host named Bill Wattenberg broadcasting out of SF last night talking about how the line voltage we get is wasteful whe it's more than 115 V, and that 115 is the optimal voltage for most appliances, etc.

He also claimed that we could save 1% of our national energy use if they just backed down the voltage to 115, but that it would mean fewer profits to the utility companies if they did.

I have no idea why I measure up to 127 V at some residential sites and a low as 112 V at others. Is it the distance of the wire or the number of users that causes them to want to boost the voltage?

INTEGRA Bespoke Lighting
12-17-2007, 11:59 AM
I have a bit of experience with this. Here in Ontario, when the summer heat is upon us, our Provincial Electrical Authority will reduce the voltage on the grid from 120-122 to around 115 volts. This is in an effort to save the demand of total megawatts and thus reduce our necessity to import power on those hot humid days.

It plays havoc with the installation of Low Voltage Lighting Systems!! It has become a real pain in the arse, requiring seasonal adjustments to many of the large, multi-tap systems I install. (Another reason moving to LEDs is so opportune... but that is another thread.)

As for your different voltage readings at different sites. This has to do with the electrical infrastructure. Older grids, different wiring, different step down transformers, distance from transformers, etc etc... all come into play here. Our infrastructure is rather old on many of the rural roads, transients, spikes and surges are a constant issue. To help ameliorate these, I have resorted to having a whole home power conditioning system installed in each large lighting system I install. This greatly reduces the number of premature lamp failures and as an added benefit for the client, it protects all of their systems from damage caused by spikes and surges.

Have a great day.