Hi,

I have an outdoor lamp at my house that is/was using a power transformer for the lamp. First question: Why?

The wires on one of the windings has been ripped off the unit and the base of the unit is very rusty. I do not know the manufacturer or the specs of the unit. So, I bought one, taking a guess that this might work -- the Radio Shack 273-1512B.

Second question: How do I connect it? Based on what I read in this forum, I am assuming that I would connect the two black wires from the primary winding to the power source -- the wires coming into the lamp post from the house. I am just a bit unclear however on what I connect to the black and white wires coming from the lamp itself. Is it as simple as connecting the white wire to one of the yellow wires in the secondary winding and connecting the black wire to the other yellow wire? I am assuming also that I would not use the center-tapped secondary black wire.

Thanks,
- Brownie

The low voltage lights are popular for many outdoor applications, there are several kits for lighting landscaping and walkways around homes.

A picture would help me identify what you have.

The transformer by Radio Shack does not look nor stated to be rated for what you want to repair. Do not use it until more research is done to show you this is fact.

The transformer you propose is only for printed circuit boards, and I doubt it will last outdoors.

A picture or a detailed explanation would be great to help determine what you need.

If anything could be used would be what we call a chime transformer, available 120 AC volt primary to 24 volt AC secondary, or which ever the volatage of the lamps, and will include proper grounding wires, and while not necessarily built for true wet locations, with proper protection from water, will last.

Parts or replacement fixtures may be available for your system, many times the fixtures costs less than parts.

tkrussell: thanks. Where can I post pictures here? Also, where can to go to get ratings of various transformers?

Thanks,
- Brownie

In the window that pops up when you answer a question, in the upper bar is a paper clip, here is where you attach various file formats.

Each transformer is rated via a stamp on the unit and/or listed in the manufacturers literature.

tkrussell: Ok. I am not at home now, but tomorrow morning I will take pictures of the old transformer, the light and the power source (the wires into the lamp post)
Unfortunately, there is no literature with the new transformer. There are specs on the back of the packaging however:
Input: 120VAC, 60Hz
Output (load): 25.2VAC C.T.@2A
Output (noload): 27.7VAC
Current (load): 760mA max
Current (no load): 140mA max

If it had a NEMA or IP rating, it would be listed on the unit or in the specs,and state where it is allowed to be located. There should also be a UL listing or label on the unit to be listed as usable connected directly to building wiring..

tkrussell: Ok. I am not at home now, but tomorrow morning I will take pictures of the old transformer, the light and the power source (the wires into the lamp post)
Unfortunately, there is no literature with the new transformer. There are specs on the back of the packaging however:
Input: 120VAC, 60Hz
Output (load): 25.2VAC C.T.@2A
Output (noload): 27.7VAC
Current (load): 760mA max
Current (no load): 140mA maxmost low volt lites use 12 V... they do sell 12 v 60 / 75 w electronic transform that would fit inside the weather proof box

Ok, so we are assuming that the transformer is down-converting and not up-converting?

I would post pictures but I don't know how to make them small enough to be able to post; zipping even one of them generates a zip file that is to big to attach to a posting.

Send a PM to admin, they will help with attaching photos.

We use step-up and step down terminology for transfomers, you need a 120 volt/? Volt step down transformer. What is the voltage of the lamps? That will be the secondary voltage needed.

Most outdoor low voltage lighting systems use 12 volt AC. The transformer must be UL listed, rated to be located outdoors and be able to be installed in an enclosure and must be grounded.

Best to find a replacement part for your brand of fixture.