2?nd Question to keypads and UL

[stepke]

Hi,

i tried to reply on the answer to Hal, but it didn`t work. Don`t know why. So i`m starting again.

The System my customers wants to install is a bus system with a power supply 29V to 31V 640mA (ELVP). This power supply supports max 64 devices as keypads (push button sensors), LCD panels;actuators. The devices are wired with a cable AWG 18. The devices are programmable devices. The load is switched by the actuators and seperated from the bus system itself.

We already know, that the actuators and power supply must be UL listed. But what`s with the keypads and LCD Panels which are only supplied by the power supply? Is a UL Listing required? I haven`t found anything special in UL or NEC, where it is described.

We heard, that inspectors just check the line voltage part in regard of safety for fire, electrical shock .... .

Thanks for your help

Stepke

 

[Dennis Alwon]

Around here almost everything electrical must be UL listed or another third party. Here is what the nec has to say about it. I would definitely check with your local authority. Esp. if you are in Germany... who knows what they want...:grin:

110.3 Examination, Identification, Installation, and Use of Equipment.
(A) Examination. In judging equipment, considerations such as the following shall be evaluated:
(1) Suitability for installation and use in conformity with the provisions of this Code
FPN: Suitability of equipment use may be identified by a description marked on or provided with a product to identify the suitability of the product for a specific purpose, environment, or application. Suitability of equipment may be evidenced by listing or labeling.
(2) Mechanical strength and durability, including, for parts designed to enclose and protect other equipment, the adequacy of the protection thus provided
(3) Wire-bending and connection space
(4) Electrical insulation
(5) Heating effects under normal conditions of use and also under abnormal conditions likely to arise in service
(6) Arcing effects
(7) Classification by type, size, voltage, current capacity, and specific use
(8) Other factors that contribute to the practical safeguarding of persons using or likely to come in contact with the equipment
(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.