Voltage Drop problem

[brittle]

Here is the situation.

A developer used a low voltage lighting system to illuminate the left and right sides of a subdivision entrance. Power is available on one side of the street only. Low voltage cable is run under the street in a 3" drain pipe. The homeowners have hired me to increase the lighting output of the existing system, or remove it with a substitution. The lights are bright enough on the side close to the transformer, but across the street is just glow. Major VD.

I've tried to pull the wire out of drain pipe but no joy. It won't budge.

Question: Is there a way to boost the voltage in order to get the 12 Volts needed 150' from the transformer?

 

[guschash]

What kind of x-former? Maybe you can change the leads on the primary side, to give you the 12v. Some x-formers have 3 different leads ( black 12v,blue13v,yellow14v) depending on the distance. You want 14v for that distance. You also need #6 wire.

 

[iwire]

I doubt you will be able to make this work decently and with in the NEC rules.

The voltage drop is affected by the amount of load, distance and wire size.

150 feet is way to far with low voltage lighting unless your running really large copper.

Tell us more about this, how many fixtures total, how many fixtures across the road, what is the wattage?

What type and size wire is run under the road?

Keep in mind a 25 watt lamp at 12 volts draws 2 amps, it adds up fast.

 

[hbiss]

Aside from what Bob said, 3" pipe with that little wire in it shouldn't be a problem unless it collapsed or got filled with concrete. Probably filled with soil to some extent. I would expose both ends and shoot some high pressure water through. It is a drain pipe after all.

-Hal

 

[infinity]

I would cut the wire where it enters the pipe and run a new piece back to the transformer and splice it on to the piece entering the pipe. This would split the load up. I would even consider inscreasing the wire size on this new piece of cable. Changing the taps on the transformer won't help because the first few fixtures will still burn brightly and your lamp life will be shortened on those fixtures.