UL Standard for RTU's

[jtester]

Does anyone know of a UL standard for RTU's, remote terminal units? I have a Contractor who wants to use a local guy to supply the controls for a water well and tank field. The local shop will purchase plc's, relays, and other components, stick them in an enclosure with a radio, and use them to operate the wells based on tank level.

The State of New Mexico requires equipment to be UL listed if a listing exists, however I can't seem to find one.

Jim

 

[jim dungar]

The appropriate number is UL508A.
This cover just about every general use/stand alone control panel.

 

[JWCELECTRIC]

Does anyone know of a UL standard for RTU's, remote terminal units? I have a Contractor who wants to use a local guy to supply the controls for a water well and tank field. The local shop will purchase plc's, relays, and other components, stick them in an enclosure with a radio, and use them to operate the wells based on tank level.

The State of New Mexico requires equipment to be UL listed if a listing exists, however I can't seem to find one.

Jim

Just make sure the Contractor can UL list the RTU panel or it won't be accepted as specified

 

[Jraef]

... The local shop will purchase plc's, relays, and other components, stick them in an enclosure with a radio, and use them to operate the wells based on tank level...

If he can find UL listed PLCs, relays and other components, INCLUDING the radio transceiver, AND he is a UL508A shop, he can do that. If any component, i.e. the transceiver, is not UL listed, there is also a UL508A procedure to allow the use of "unevaluated components" when special (and somewhat onerous) rules are followed.

By the way, if it was a WASTEWATER wet well control panel and RTU where the area is considered classified and requires intrinsic safety relays, then it falls under a slightly different UL panel regulation, UL698A I believe.