In WA State:
http://www.lni.wa.gov/TradesLicensing/Electrical/files/currents/elc05_02.pdf Underground Low-Voltage Landscape Lighting Requirements
We have been asked to clarify the intent of the rules relating to licensing, certification, allowable exemptions, and permits and inspections for the installation of underground low-voltage landscape lighting. WAC 296-46B-925(7) establishes a threshold for exemption for a specific type of this work and is prefaced with the qualifier “The electrical failure of these systems does not inherently or functionally compromise safety to life or property.” This quality is mandatory for consideration for this exemption.
This rule’s format was made general enough to include thermocouple derived circuits and low-voltage systems for residential vacuum systems, underground landscape sprinkler control, and residential garage door controls, along with underground low-voltage landscape lighting. (The Class 2 power source for these other systems is always integrated into the listed controller equipment.) It was the intent of the rule to allow “exempt” installation of Class 2, pre-assembled, low-voltage lighting assemblies listed for use underground. These packaged Class 2 low-voltage lighting systems with fixed numbers of luminaires can be safely installed by persons with no electrical installation knowledge or skills. Most of these systems are completely pre-wired and only need to be “planted” then plugged in. Some may allow change of location of the luminaire(s) on the conductors pre-wired to the Class 2 transformer. The Class 2, 100 VA limitations of these packaged assemblies satisfies the above safety parameter of the rule.
When an installation involves field assembly of individual lighting fixtures on properly sized conductors and selection of an appropriate Class 1 transformer or power source to supply the calculated loads, then the inherent safety of the listed Class 2 system is nonexistent. The installation must be done by licensed electrical contractors and certified electricians. Work in this scope is only included for 01-general journeyman, 02-residential specialty, or 06-limited energy specialty contractors and electricians. The 06-limited energy specialty is further restricted to Class 1 power-limited circuits 1000 VA, 30 volts or less.
The rules have an exemption from licensing for firms that install certain cord and plug connected equipment in WAC 296-46B-925(9) with the qualifier that “The equipment must be a single manufactured unit that does not require any electrical field assembly except for the installation of the plug and cord.” Field installation of low-voltage lighting systems does not qualify for this exemption, even if the power source happens to be cord and plug connected. There is no exemption from permits and inspection for this work in WAC 296-46B-925(9). Field assembled underground low-voltage lighting systems require electrical work permits and inspections. Licensing, permits and inspections are not required for the specific work exempt under WAC 296-46B-925(7).