Malibu Transformer Installation

[jkass636]

Hello I am new to landscape lighting and want to know if it ok to mount a malibu transformer(600watt) inside a garage attached to a home. The power pack or transformer get hot when on, I hear this is normal. The wattage is not exceded so everything is installed correctly. If this is typical what's the difference if I mount it inside the garage, malibu says it must be outside?? Anyone please help...Thanks

[sitelights]

Thank you for your question; this response is my 500th post on this site and gives me the opportunity to add a mild sting to the topic.

The heat generated by the transformer is not the issue; it is the wall penetration. The stipulation of outside mounting only is a way to absolve Intermatic (Malibu) of any responsibility if the low voltage cable were improperly placed in or through the wall.

A magnetic low voltage lighting transformer (which is what you have) produces heat and it is air cooled. Placing the transformer indoors in the wrong location could result in the circulation of ambient air being insufficient to properly cool the unit.

Professional low voltage lighting designer/installers have an obligation to meet or exceed stipulations stated by the manufacturer as well as the NEC. There is a standard for low voltage outdoor lighting developed by Underwriter's Laboratories that deals with safety hazards that could result in damage, injury or death. This is the unpopular UL1838 that is dealt with at some length on this site.

I characterize UL1838 as unpopular because the restriction on transformer output higher than 15v would deny the majority of professional lighting designer/installers an easy way to solve the problem of voltage drop by simply using the highest output voltage (up to 22v) necessary to provide the lamps with voltage in the 10.5v to 11.5v range. These higher voltages allow the use of undersized low voltage cable to meet the target voltage.

A brief search of the site will turn up a number of posts on the topic of UL1838 and the sometimes heated discussions generated (no pun) by the use of voltages up to 22v as opposed to the 12v to 15v range recommended by the standard and required for UL listing. This topic may interest even the DIYer.

Homeowners can do as they please but the professional is obligated to assume the liability inherent with substandard work.