Omega Engineering PX2670 manual Mounting, Fittings

The Model 267 voltage output is a 3-wire circuit, with three terminals available for wiring (see Figure 1). The -Excitation and -Output are commoned on the circuit (see Figure 2A). The 267 voltage output can operate from either AC (9-30 VAC) or DC (12-40 VDC) excitation. The 267 has a 0-10 VDC output, calibrated at the Factory.

Figure 2	PX 2670
	Transmitter
	(4 to 20 mA)

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Power

Supply

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Load

(Monitor)

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Figure 2A

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Power

Supply

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PX 2670

Transducer

(Voltage)

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Load

(Monitor)

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Current Models

The current output transmitters are true 2-wire (See Figure 2), 4-20 mA current devices and deliver rated current into any external load of 0-800 ohms. The 4-20 mA current units are designed to have current flow in one direction only - please observe polarity. The PX2670 can operate over a voltage range of 9 to 30 VDC. It has been factory calibrated at 24 VDC into a 250 ohm load. The minimum and maximum power supply must be capable of delivering these voltages to the PX2670. Thus, the

minimum and maximum power supply calculation is shown and depicted in Figure 4.

MIN Supply Voltage: 9 + 0.02 x (resistance of receiver plus line)

MAX Supply Voltage: 30 + .004 x (resistance of receiver plus line)

Mounting and Pressure Fittings

Mounting

The PX2670 Series are designed to be mounted with the two holes located on the base of the housing. The holes are sized to accept a #8 screw.

Fittings

Two (2) 3/16” O.D. pressure fittings are supplied for pressure signal connection with a 1/4” push on tubing. Both positive (high) and negative (low) pressure ports are located on the bottom face side of the unit. For best results (shortest response time), 3/16” I.D. tubing is suggested for tube lengths up to 100 feet long, 1/4” I.D. for tube lengths up to 300 feet long, and 3/8” I.D. for tubing lengths up to 900 feet. The high and low ports are labeled next to each respective port (see Figure 3).

Calibration Figure 3

All PX2670 Series pressure transducers and transmitters are factory calibrated and should require no field adjustment. How- ever, both zero and span adjustments are

accessible under the cover of the unit (see Figure 1), below and to the right of the terminal strip. Whenever possible, any zero and span adjustments should be corrected by software in the user’s control system. Us the zero and span adjustments only if necessary. The PX2670 Series are calibrated in the vertical position at the factory (baseplate vertical). For use in other orientations, position the unit and follow the zero adjustment procedure listed below. Pressure ranges are fixed and cannot be changed in the field. If a range change is required, contact the factory for a replacement PX2670 model with the appropriate pressure range.