# Found a Lighting Fixture and have no clue how to wire it.

Joined May 14, 2014
7
My first post on AllAboutCircuits.com is a fairly simple one.

I found this lighting fixture on the side of the road no too long ago, and finally spent some time to disassemble it to get a better look.

It looks like a HPS system used for street lights or maybe some sort of industrial lighting.

There is the light socket itself, a transformer, a MMKT80 Cap with a parallel diode, and two resistors.

The power connections hook to the Transformer, and to each side of the socket ( white wire on one side, black on the other.)

I just don't know a lot about these lighting circuits, and would love to actually hook a light up to eventually utilize outdoors.

I found a Mercury lamp not to long ago as well that fits in the large socket.

It is a HPS 150W bulb. Will this work?

Any help is appreciated.

Thanks!

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#### #12

Joined Nov 30, 2010
18,223
This is how that kind of fixture is made, but nobody can tell from the photos which kind you have or how to sort out the wiring diagram. Can you make a drawing and read some labels for us?

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Joined May 14, 2014
7
This is how that kind of fixture is made, but nobody can tell from the photos which kind you have or how to sort out the wiring diagram. Can you make a drawing and read some labels for us?

Here you go!

The wires are colored to correspond to what I have sitting in front of me.

I see this "ignitor" in your included picture. What exactly is this component?

Thanks,

Andy

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#### #12

Joined Nov 30, 2010
18,223
The igniter fires a high voltage pulse into the bulb to get the arc started. After that, the inductor limits how much current can pass through the bulb and the igniter goes quiet.

What kind of power source do you have that has 3 wires? Why is a black wire going to the socket and nowhere else?
Red looks like, "hot" and gray looks like neutral...so far. Why does the socket have 4 terminals and where do they go? Are some of them dummies? Do they all attach to the bulb in some way?

#### williamj

Joined Sep 3, 2009
180
That looks like a sodium or metal halide bulb, it's 3ph at 228, 240 or 480 volts (US). It's used for industrial and/or commercial lighting. 10/15 years ago those bulbs cost $80.00(US) apiece. I don't know about the rest of the circuitry but that transformer is wired incorrectly, input voltage goes to the low side and output voltages come out the high side. Been away from it all for far too long tell you much more about it, sorry. Last edited: #### shortbus Joined Sep 30, 2009 9,322 My first post on AllAboutCircuits.com is a fairly simple one. I found this lighting fixture on the side of the road no too long ago, and finally spent some time to disassemble it to get a better look. It looks like a HPS system used for street lights or maybe some sort of industrial lighting. There is the light socket itself, a transformer, a MMKT80 Cap with a parallel diode, and two resistors. The power connections hook to the Transformer, and to each side of the socket ( white wire on one side, black on the other.) I just don't know a lot about these lighting circuits, and would love to actually hook a light up to eventually utilize outdoors. I found a Mercury lamp not to long ago as well that fits in the large socket. It is a HPS 150W bulb. Will this work? Any help is appreciated. Thanks! Also be aware that your mercury lamp and the HPS take different type ballast's. The output voltages from each type of ballast are different. Thread Starter #### asbradford852 Joined May 14, 2014 7 That looks like a sodium or metal halide bulb, it's 3ph at 228, 240 or 480 volts (US). It's used for industrial and/or commercial lighting. 10/15 years ago those bulbs cost$80.00(US) apiece.

I don't know about the rest of the circuitry but that transformer is wired incorrectly, input voltage goes to the low side and output voltages come out the high side. Been away from it all for far too long tell you much more about it, sorry.
I thought it had to be 3ph. the transformer only has one side with two terminals, the other end has only one that two blue wires go off of into the circuit.

It's got me buffaloed!

Joined May 14, 2014
7
The igniter fires a high voltage pulse into the bulb to get the arc started. After that, the inductor limits how much current can pass through the bulb and the igniter goes quiet.

What kind of power source do you have that has 3 wires? Why is a black wire going to the socket and nowhere else?
Red looks like, "hot" and gray looks like neutral...so far. Why does the socket have 4 terminals and where do they go? Are some of them dummies? Do they all attach to the bulb in some way?
I'm just giving it to you like it is!

The gray is actually a white wire.

The actual socket has a blue and white wire sticking out of the bottom. The white wire goes to the terminal block on one side of the socket. The blue wire goes to the transformer and the cap. The black Power wire comes up to other terminal block for the socket, but thats it, it stops cold.

Something could be missing.

#### williamj

Joined Sep 3, 2009
180
My mistake, the transformer isn't a transformer it's a "reactor". These look like your lamp.

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Joined May 14, 2014
7
So I believe I am missing a starter.

well.....

Does the reactor introduce some impedance into the circuit?

What is it's main function?

#### inwo

Joined Nov 7, 2013
2,419
Is the part labeled "power source" a female twistlock plug?

Joined May 14, 2014
7
Why yes it is.

#### inwo

Joined Nov 7, 2013
2,419
Then that isn't the power connection. It's the photo cell/relay module connector.
In, out, and common.

So power connects to lamp socket.
Unterminated black. Which feeds photo/relay.
White/grey = common.

Jumper red and black to power circuit.

Looks complete. But what lamp and wattage?

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