QUESTION_FUEL_PUMP_TEST_STAND.docx

QUESTION: It has come to our attention that in order to measure 3-Phase 400Hz power (volts, Amps, Frequency, Watts, P.F. etc.), COTS transducers for such measurements to feed into the Siemens PLC I/O modules ARE NOT rated for Class1, Div. 1, nor Div. 2 group D, as required (Ref SOW par 1.2)

Does the technical team have a source that complies with SOW 1.2 related to the 3-Phase 400Hz measurement components? And if so, can you please advise what brand they are? We can plainly see that Nematron, Siemens, and Strong Arm have been defined in the SOW, so I suspect the 400Hz instrumentation OEM is known as well.

ANSWER:

Contractor shall find out how to be in compliance with National Electrical Code. If the contractor cannot find rated components, below is an option to bring non-rated components to compliance.

All components not rated for use in a hazardous environment shall be mounted in Explosion Proof (EP) enclosures. These enclosures shall be cooled via thermo-electric cooling pads (TECs). The TECs transfer the heat from the enclosure to rear-mounted heat sinks. The heat sinks are cooled by air supplied by the explosion proof blower motor mounted beneath the EP enclosures. The status of the blower motor is monitored by the PLC via a current transducer. The PLC controls the starting and stopping of the compressor via a relay. The temperature within EP enclosure shall be monitored via an RTD in each enclosure.

Also for clarification, Air purged shall not be used if this is questioned.