Hall Effect Pickup in CID2 Area

[fifty60_4802GND]

Several years ago I had an argument with someone about turbine flow meters in CID2 areas. The flowmeters have a hall effect sensor installed on them that sends counts back to a PLC. There are no explicitly CID2 labelled versions of this hall sensor/pickup, only IS versions and explosion proof versions. I don't think these pickups would need to be IS or Explosion proof. They are not current interrupting, and their temperature is well below the ignition temperature.

Short of sending these in to UL/FM/Intertek for evaluation (which I may look in to actually), what would I need to do to justify using them in a CID2 area? Can you please point me towards the code sections I would use to make this judgment?

 

[Devin Hanes]

501.105 Meters, Instruments, and Relays.
501.105(B)(2)

(3) Resistors and Similar Equipment. Resistors, resistance devices, thermionic tubes, rectifiers, and similar equipment that are used in or in connection with meters, instruments, and relays shall comply with 501.105(A).
Exception: General-purpose-type enclosures shall be permitted if such equipment is without make-and-break or sliding contacts [other than as provided in 501.105(B)(2)] and if the marked maximum operating temperature of any exposed surface will not exceed 80 percent of the autoignition temperature in degrees Celsius of the gas or vapor involved or has been tested and found incapable of igniting the gas or vapor. This exception shall not apply to thermionic tubes.

501.105(A) if max temperature is not marked

(A) Class I, Division 1. In Class I, Division 1 locations, meters, instruments, and relays, including kilowatt-hour meters, instrument transformers, resistors, rectifiers, and thermionic tubes, shall be provided with enclosures identified for Class I, Division 1 locations. Enclosures for Class I, Division 1 locations include explosionproof enclosures and purged and pressurized enclosures.

 

[rbalex]

Begin in Section 501.105(B). Read the whole Section carefully. The Subsections interlock quite a bit.