Installing a 5 ft post light in my yard. Want mercury vapor but most fixtures are ugly. So I took a incadesent fixture and a hubbell mercury vapor. Switched out ceramic lamp holder in light. Now need to add the transformer. Will it be any problem if I install this in the base of the post? So like adding 5 ft #12 wire between transformer and bulb. The type of post flares out at the bottom so there is plenty room. And do I need to ground the transformer? Post comes in two parts was just going to hang the transformer down into the base with a small piece of cable.
Thanks for any input

Certain fixtures are designed to be used with certain bulbs only.

In the ones I've seen, there are usually stickers inside the lamp that say "Warning, to avoid risk of fire, use only with Type "X" bulb at Y wattage."

Sometimes there are warnings on the package too.

Let me see if I am reading this right:

You are using the Mercury Vapor Lamp + Lamp Holder in the Non-Ugly Incandescent Fixture, plus are mounting the Ballast remotely?

If so, that's OK as long as the Luminaire will be able to both house the Lamp, plus deal with the Lamp's heat (the Merc. Lamp will run very hot, as compared to an Incandescent Lamp).
Also, use the Mogul Base Lamp holder (if Mogul??) which was in the original HID Luminaire (fixture).

You may remotely connect the Lamp / Ballast using #12 THHN cu for the lead-in wiring.
Be sure to keep the original Conductors on the HID Lamp Socket (the High Temp jacketed wires), and connect the THHN wires to them at least 8" away from the Lamp.

You may be able to use smaller than #12 THHN cu for the lead-in wires (from the Ballast to the Lamp), depends on the distance plus the wattage.

If this HID is in reality a Pulse-Start Metal Halide lamp, then the maximum remote range is wayyyyyy shorter! Also, the use of a Long-Range Ignitor comes into effect.

Scott35

BWHAHAHAHA

incidently just came from a job where the
'lady of the house' had borrowed fixtures from a lighting shop, had me holding them up like Vanna White while she himmed & hawwed....

'ugly ?'

'yeah..ugly !'

'next please...'

'hmmmm.....'

Hey Ray,
Drop this baby in....
Mercury Vapor Lamp Ballast
Catalog Number 74P3303
For 175W H39
60 Hz HX-NPF
POSTLINE BALLASTS
For high intensity discharge lighting applications
Utilizing HID lamps in post mounted applications
Exclusive spring clip and chain (factory pre-assembled on all ballasts 100 watts and greater) maximizes ballast life by providing a path for heat dissipation. Experience has shown that without adequate heat transfer, ballast life will be shortened. The spring clip holds the ballast against the interior pole wall, thus allowing the ballast to transfer its heat to the pole. The 18" long chain permits the ballast to be lowered into the pole, eliminating heat buildup around the ballast. The results are increased ballast life and elimination of ballast cycling.Simply attach chain to a convenient tie point at pole top, connect leads and push ballast down pole.
http://www.advancetransformer.com/products/postline.asp

Thanks
Using a 100 watt mercury vapor. Will have to see if the original fixture holds up to the heat. Is metal but has plastic glass in it. I did something like this with a 70w HPS exterior light on a brick wall. Light had a large base so just a double deep 2 gang box in the wall to hold ballast. Has been working fine for about 5 years now. Wanted a whiter light and to keep bugs away from front door so this is why the new post light.
Thanks

Rayh78:
Not to burst your bubbles, but what you are doing sounds like it not in compliance with the NEC. If you are worrying about the "plastic glass" melting, then you should seriously re-think your "light".

By modifying fixtures (luminaires) you void the UL listing.

You also mention a 2 gang double deep box to put the ballast in???

BTW, YES, the ballast MUST be grounded.

John

The double deep box was for a different out door wall fixture. Was for a 70 watt HPS and the ballast would not quite fit in a single box.
On this post fixture with a 100 watt mercury vapor it has 4 plastic lense panels I guess like what they call a coach light. But the 100 watt mercury vapor lights I see at home depot and lowes also have a plastic lense.
thanks

"incidently just came from a job where the
'lady of the house' had borrowed fixtures from a lighting shop, had me holding them up like Vanna White while she himmed & hawwed....

'ugly ?'

'yeah..ugly !'

'next please...'

'hmmmm.....'"
Almost blew milk out my nose picturing that How much did the job go up after that

Walrus;

I DID blow Milk (actually Squirt which really hurt) out my Nose, while imagining Steve modeling the Fixtures!
LOL!!!

Scott35