[E-Z]

First off, I want to thank all the experienced DIYers, and especially the pros who post to this board. I've spent quite a bit of time here already, searching topics and following threads. I'm impressed by the consistently clear and thorough answers, and the patience shown by everyone giving them.

My first question is simple (I think.)

The PO of my home installed a high pressure sodium security light on the detached garage. It lights things up well enough, but isn't my idea of "garden lighting." (IMO, these lights are more suited to barnyards and truck stops.. but that's just MO.)
I'd like to replace it with a photocell-controlled, dual floodlight fixture with PAR 38 CFLs. (Still not mood lighting... but a little less harsh and a bit more energy efficient.)

The current HPS light is mounted to the stucco wall, under the eaves, and is fed via an MC cable that passes through an appx 1/2" hole in the stucco, behind the light.
I usually like to do the cleanest install possible, but the stucco on the garage is 3/4" to 1" thick, and the inside is not accessible, so I'd like to avoid cutting a hole in the stucco and trying to install an internal JB.

The quicker (and a little dirtier) solution I see is to install an external "bell box" on the stucco wall, and attach the fixture to that.
I'd like to re-use the existing MC, if I can. Since the hole behind behind the box won't be big enough for cable + clamp, I'd like to attach the cable to the box by threading a clamp to the inside of the box. I'd then apply a ring of caulk to the wall, around the hole the cable passes through, before mounting the box.

From what I can find in the NEC (2008) this seems OK as long as I allow the equivalent of one conductor for box fill (for the internal clamp), and as long as everything is protected from the entry of moisture.
Since the box is under the eaves and is fully sealed except for where the MC enters, and I plan to seal that with caulk, it would appear to me that I've satisfied the requirements for such an installation in a damp location.
(NEC doesn't seem to be too specific on exactly how moisture should be excluded, unless I've missed something.)

Does anybody see anything wrong with any of this?

Thanks again!

 

[InPhase277]

Does anybody see anything wrong with any of this?

Yes, you won't be able to insert the MC into the end of the connector if you put it inside the box. The connector has a stop in the throat so the end of the cable rests against it.

Why can't you gently chisel some of the stucco away to get the connector to fit? It ain't got to be pretty, the box is taking care of that.

 

[E-Z]

Yes, you won't be able to insert the MC into the end of the connector if you put it inside the box. The connector has a stop in the throat so the end of the cable rests against it.

Why can't you gently chisel some of the stucco away to get the connector to fit? It ain't got to be pretty, the box is taking care of that.

Thanks for the reply. Makes sense. I didn't have an MC connector in hand to look at, so I didn't think about the stop. (Guy in the big box electrical dept. gave me a pack of NM connectors and assured me that was what I needed for MC.)

Went back to get the right connector today and found a thread-in connector that will fit my MC. That seems like it might be a better solution, since there doesn't need to be a clamp inside the box, and I don't need to clear room for one inside the stucco.
It's still not moisture-tight, but again I'd apply a ring of caulk between the box and the stucco, around the cable's point of entry to hopefully take care of that.

Again, I'd appreciate any input on whether this ought to satisfy code.
...And again, thanks in advance!

 

[220/221]

If it is truely MC, with a ground wire, I wouldn't be concerned about a clamp (not code compliant)

Where's the wire gonna go? The building is finished.

You want to fight with putting a clamp inside the box, knock yourself out. There are ways to accomplish this. To me it seems like another metal edge to keep the conductors away from.

If the cable doesn't have a ground I'd figure out a way to get one on there. Chipping out a little stucco isn't that dificult. Hell, chipping a 4" round circle to accept a pan box isn't that hard. We do it all th time with an old screwdriver and a hammer or pair of sidecutters.

 

[E-Z]

Thanks.

That gives me a couple of options.

The Wire's already installed for the existing light. The garage isn't finished, but there are cabinets hung against the inside of the wall the light is. I could always take them down... and may do so, if I get tired of the Bell box on the exterior, but at this point I'd like to get a reasonably neat solution done, and make it code compliant while I'm at it.

Does MC not have to be attached at the box?

Whichever way I go, is caulk between the box and wall sufficient as a moisture barrier, if the rest of the box is watertight?

Thanks again!

 

[220/221]

Does MC not have to be attached at the box?

Code says yes

You should be able to get your connector on and push it back flush with the wall. Caulk around the hole just before you anchor the box.

is caulk between the box and wall sufficient as a moisture barrier, is the rest of the box is watertight?

Depends on how much exposure it has to rain :laughing:

There is no such thing as watertight. We can only shoot for water resistant.

 

[frenchelectrican]

If you don't like High pressure sodium luminaire why not go with metal halide luminarie that will replace HPS for watt to watt both are simauir to light level but the colour it will be much better useage for your taste { it will be more whiteish simair to cool white flourscent bulbs }

I know the Metal Halides cost little more than HPS luminiares are but they are pretty common now beside they do have pretty large CFL verison as well so those two option they can dish out pretty serious amount of light all it depending on the mounting height once I know the mounting height I can able tell you what the correct wattage you can use.

Merci,Marc

 

[E-Z]

Thank you both.

Chipped out enough stucco to make a recess for the clamp on the back of the box, put a nice big ring of caulk around the hole, and mounted it up.

It's nice to be rid of that buzzing, flickering high-pressure-sodium monster.

If I knew how easy chipping the stucco was going to be, I probably would have just made a big enough hole for a recessed box, and mounted the fixture flush.

Is some sort of "old work" box allowable for this kind of application, or does the box have to be attached from the inside?

Thanks again!

 

[E-Z]

If you don't like High pressure sodium luminaire why not go with metal halide luminarie that will replace HPS for watt to watt both are simauir to light level but the colour it will be much better useage for your taste { it will be more whiteish simair to cool white flourscent bulbs }

I know the Metal Halides cost little more than HPS luminiares are but they are pretty common now beside they do have pretty large CFL verison as well so those two option they can dish out pretty serious amount of light all it depending on the mounting height once I know the mounting height I can able tell you what the correct wattage you can use.

Merci,Marc

Thanks for the recommendation.
Sorry I didn't see your reply sooner. I must have been responding to the other replies at the same time you sent yours, so I missed it.

One of the problems I had with the high pressure sodium was that it was too much light, and the wrong kind of light for the area. I replaced it with a simple, old-style, two head floodlight unit, and used a pair of 23W CFL PAR38 flood bulbs. (Also installed a photocell unit to turn them on automatically at night.)
By being able to focus the light where I want it, I'm actually getting more useful illumination, but with softer light that's more suitable for the area.

Certainly not a very high-tech solution, but it seems to be working well so far. I have adequate light for security, with the annoying hum and glare of the high pressure sodium.

Thanks again for your suggestions!

 

[Burbman]

If you don't like High pressure sodium luminaire why not go with metal halide luminarie that will replace HPS for watt to watt both are simauir to light level but the colour it will be much better useage for your taste { it will be more whiteish simair to cool white flourscent bulbs }

I know the Metal Halides cost little more than HPS luminiares are but they are pretty common now beside they do have pretty large CFL verison as well so those two option they can dish out pretty serious amount of light all it depending on the mounting height once I know the mounting height I can able tell you what the correct wattage you can use.

Merci,Marc

Ummm, yeah....I replaced two sodium fixtures on the back of our church with 100W metal halides and it's like being on the mound at Yankee Stadium at a night game....Excellent lighting but probably not the look the OP was going for.....

 

[220/221]

If I knew how easy chipping the stucco was going to be, I probably would have just made a big enough hole for a recessed box, and mounted the fixture flush.

Chipping out a little stucco isn't that dificult. Hell, chipping a 4" round circle to accept a pan box isn't that hard. We do it all th time with an old screwdriver and a hammer or pair of sidecutters.

:whistling2:

 

[E-Z]

:whistling2:

Yep... Guess I shoulda listened!

I think my thinking was colored by recent experience. I was visiting friends overseas, where most home construction is reinforced concrete. I helped them out with a couple of little projects that involved drilling a few 6mm holes in their interior walls. Took about 45 minutes with a masonry bit per hole! For some reason, I expected the same with the stucco.
Live and learn!

One question I'd still really appreciate an answer to, if anyone knows: Can some sort of "old work" box be used for a light fixture on an exterior stucco wall, or does there need to be access inside the wall?


Thanks again!

 

[InPhase277]

One question I'd still really appreciate an answer to, if anyone knows: Can some sort of "old work" box be used for a light fixture on an exterior stucco wall, or does there need to be access inside the wall?


Thanks again!

An octagon box could be used with what we in the South call "Jiffy Clips". Others call them "Madison Clips" or "F straps". But I don't get that warm and fuzzy feeling from them hanging upside down. You could also cut a hole between rafters and use one of the bracket boxes for old work ceiling fan support, though these are about $15 apiece.

 

[E-Z]

Thanks..

Actually, I was wondering whether there's a way to mount some sort of "old work" box on an exterior stucco wall.
I'd be curious both as to how to do it, as well as whether it would satisfy code.

Can some sort of "old work" box be used for a light fixture on an exterior stucco wall, or does there need to be access inside the wall?

Thanks again!

 

[InPhase277]

Thanks..

Actually, I was wondering whether there's a way to mount some sort of "old work" box on an exterior stucco wall.
I'd be curious both as to how to do it, as well as whether it would satisfy code.



Thanks again!

Same thing. It depends on what you are going to hang on it. A receptacle box could be mounted with jiffy clips. With a light, I'd either try to hit the center of a stud so that I could screw a pancake to it, or I'd use the box brace system that I posted above, but that would be tricky.