skip to main content

Electrical Wiring

mounting low voltage control or bell transformers

5 years ago

I've seen doorbell transformers mounted on the outside of main service panels. I don't recall how the 120V was connected, but IIRC, it just goes via simply insulated wires (vs. cable) to the outboard transformer that is mechanically mounted via "feet" in a bracket. It that correct and allowable? It seems somewhat suspect since there is not cable, but individual conductors with very simple insulation (not much mechanical protection).

I see instructions for mounting HVAC control transformers in a special box cover that encloses the high side connections leaving the output, low voltage side free and visible. These instructions also include mooting like in the previous paragraph, apparently, but I find them somewhat ambiguous.

Can someone explain to me, or point me to an explanation about how this transformer mounting is supposed to be done? By way of explanation, this is not a home-wiring question. I want to put a low voltage transformer on or in an existing (purpose-built) junction box on a commercial appliance chassis, but the same safety principles should apply.

Sort by:Oldest

Comments (4)

yankee4210
5 years ago

I've always done it like this, or some variation (maybe substituting a handy box for the 1900 box if space is an issue). As long as your line voltage side is kept separate and enclosed in boxes with proper connectors, covers, etc etc as it should be, you're good to go.
ionized_gw
Original Author
5 years ago
Thanks yankee. In the first pic, there is some minimal exposed wire between what looks like a service panel, but could be a junction box, and the transformer body, or is the transformer butted against the box metal? What kind of connection do you use in that situation between the metal parts? (Is some kind of connector to mechanically connect the transformer to the knock-out and protect the wire included with the transformer?
Related Discussions
Malibu 600w Low voltage transformer photocell question
Q
Comments (3)
yes you can use the 1 photocell for your 600w transformer. The bigger issue is about using a malibu transformer in general. Low voltage landscape lighting has voltage drop (the longer the run, the more lights, the less voltage at the fixture). Malibu transformers do not enable you to properly compensate for voltage drop, as a results lights are often dim/uneven. If you get the chance in the future, try a multitap transformer--it has voltage ports from 12-15 volts so you can output at higher voltages to compensate for voltage drop. That way if your lights are dim, you can connect to a higher voltage tap on the transformer. All professional installers will use a multi tap transformer and they are a key factor to getting pro results. If you don't have a multitap (like a Malibu), then be sure to pay great attention to your layout to minimize voltage drop. We have info on layouts in our landscape lighting learning area. Good luck. Here is a link that might be useful: Low Voltage Transformers for Landscape Lighting
...See More
Can the Intellitouch i7 control outdoor low voltage lighting?
Q
Comments (12)
Yup- as others said usually the relay provides 120vt ac to a dedicated outlet that the low voltage lighting transformer is plugged into. Important to note local electrical code requirements may necessitate purchasing a pool and spa rated low voltage transformer (the design physically separates the 120vt side of the transformer coil from the low voltage so a coil failure won't send 120vts AC down the landscaping wiring. CAST sells these type of transformers (that what I have) which are well made and offer voltage taps that allow you to compensate for voltage drop in the wire. Here's there website: http://www.cast-lighting.com/homeowners Thier website also has some great info on how to design a lighting system and how to size the transformer.
...See More
Low voltage lighting control from Intellitouch?
Q
Comments (1)
Sure it can! Just wire an outlet to a spare relay in IntelliTouch. Then define that relay as a generic circuit. For example, AUX8 will be called Lscape Lights and will have a generic (on/off) circuit function. That's what I did. Then you can create a scheduled program for that circuit to come on every night at 8:30pm.
...See More
Low/line voltage? Transformer/no transformer? Help!
Q
Comments (5)
Depends on how you want to control them. If all you are doing is turn them on and off, it shouldn't be much of a problem. If you want to dim them, that's where issues start to crop up. Not to be too reductionist or too simplistic here, but most LEDs are solid state electronics, not really technically electrical, and require low voltage DC power, so not only is there a transformer (whether you see it or not), but usually some sort of AC/DC rectifier. Not all electronics behave well to being dimmed with typical rheostat wall switch dimmers. That's also why some LED lights have a slight delay turning on, the electronics. Even if they say they handle 120v and can be dimmed, it doesn't always work as advertised. Depending on why people on these forums recommend the Inspire LEDs (I'm not familiar with them) I would still stick with something either I know or people I respect know. If I want to dim LEDs today, I would buy a whole system that includes the lighting controller—like a Philips HUE system for traditional style light bulbs. LEDs have not been perfected to the point that anything you buy will behave properly. But if none of that matters, just get whatever you want that behaves like you want it (if you don't want the delay in turing on, for instance) Joe
...See More
yankee4210
5 years ago
The transformer is against the box, and probably has a 1/2" threaded nipple passing through a 1/2" ko in the panel, held in place with a lock ring, like in the second photo.
dennisgli
5 years ago

Related Stories

INSIDE HOUZZ See a Couple’s New Spa-Like Bathroom From Lowe’s and Houzz

By Becky Harris

The sweepstake winners’ master bathroom gets a makeover with a new shower, tile and storage space

GARDENING FOR BIRDS Wild Birds Transform a Woman’s Garden and Life

By Mary Jo Bowling

How Sharon Sorenson created a wildlife haven and became the Bird Lady of Southern Indiana

ACCESSORIES 8 Low-Cost Luxuries With a Big Payoff

By Apartment 46 for the Home

Consider the small stuff — like switch plates and throw pillows — to give your home a touch of class

MOST POPULAR Before and After: 13 Dramatic Kitchen Transformations

By Erin Carlyle

See the wide range of ways in which homeowners are renovating their kitchens

MOST POPULAR How High Should You Mount Your TV?

By Matt Clawson

Today we look at an important question to consider when locating your television: How high should you set it?

KITCHEN COUNTERTOPS 7 Low-Maintenance Countertops for Your Dream Kitchen

By Christine Tusher

Fingerprints, stains, resealing requirements ... who needs ’em? These countertop materials look great with little effort

BATHROOM DESIGN 10 Ways to Control the Cost of Your Bathroom Remodel

Bathroom designers offer 10 budget-saving tips for layouts, materials, fixtures and more

WINE CELLARS 8 Tips to Transform Your Basement Into a Wine Cellar

By Shawn Gauthier

Enjoy a "very good year" as often as you like when you curate favorite vintages in your own basement wine cellar

INSIDE HOUZZ Inside Houzz: Refaced Cabinets Transform a Kitchen

By Annie Thornton

No walls came down. No windows were added. But this once-dark kitchen looks completely different, thanks to bright new surfaces

KITCHEN STORAGE How to Get Your Kitchen Storage Under Control

By Georgia Madden

An expert offers pointers on where to start organizing the kitchen and how to keep it neat

Sponsored

More Discussions

Glow effect on portico ceiling

14

Kitchen backsplash Dilemma

10

undercounter power strip and lighting

3

Is Hubbell the only UL listed pop-up outlet for NYC Kitchen island?

4

challenging lighting situation - under upper flight of stairs

13