DEA
Engineering Company
Nutating
Micro Flowmeter
Mechanical Installation & Operating Considerations
Electronic Installation & Operating Considerations
Installation and Maintenance Instructions
ELECTRICAL CONNECTIONS
Electrical conduit can be connected to the Microflowmeter via the 1/2" NPT thread located on the top of the electronics housing. The meter is supplied with a 30" pigtail lead which is sealed at the meter housing. The Microflowmeter is certified explosion-proof for class 1, division 1, groups C & D applications. It is also certified factory sealed", thus simplifying the requirements for explosion-proof sealing fittings in the electrical conduit.
FIGURE 3: Functional Block Diagram
Electrical connections are made via a shielded five conductor cable with outer jacketing. The red lead is for 8 - 30 volt DC power. The black lead is the power and signal common and is also connected to the meter housing. The signal wire is white. The green wire is used in factory diagnostics and is disconnected and isolated prior to shipment. The bare conductor, per Safety Agency requirements, is also connected to meter housing ground and should be connected to earth ground. It is recommended that all wiring from the Microflowmeter to the power supply, displays and other interfaces be twisted, shielded 18 gauge or larger multi conductor cables. If the power supply is shared by other devices, care should be exercised to insure that the supply voltage is free of transient noise from these other sources. Typical example of problems which will require special treatment are inductive loads such as solenoids and relays. Please refer to "Trouble Shooting" for recommendations.
CAUTION: The Microflowmeter contains an internal voltage regulator which drops the input voltage to a nominal 5 volt level. Use care when wiring the meter and applying power to the the meter. If the polarity of the power supply is not correct, the regulator may be damaged.
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