Emerson Rosemount OCX 8800, Instruction Manual

Page: 59 / 306

Instruction Manual
IM-106-880C, OI
Section 2:
Installation
April 2017
Reference Air Set, Solenoids, and Blowback Option with COe Zero
Function
35
2.5.4 Reference Air Set, Solenoids, and Blowback Option with
COe Zero Function
Figure 2-14 shows the piping arrangement for the Hazardous Area OCX 8800 with the
blowback and autocalibration options when the COe Zero Function is used. The arrangement is
similar to
Figure 2-13 except instrument air is used as the Hi O
2
test gas. Refer to Section 3 for
details of the function.
2.5.5 Reference Air Set, Solenoids, and Blowback Option without
COe Zero Function
Installing a Hazardous Area OCX 8800 with the blowback option requires the addition of air
operated blowback valve, regulator and gage, and check valve.
Figure 2-13 shows the piping arrangement for the Hazardous Area OCX 8800 with the
blowback and autocalibration options. Figure 2-14 shows the piping arrangement for the
OCX 8800 with the blowback option, but without autocalibration (without test gas solenoids).
When the reference air set, calibration gas solenoids, and blowback options are included with
your transmitter, use the following procedure to install the pneumatic system components.
1. Connect the calibration gas sources according to the instructions in the previous paragraph ““Reference Air
Set, Solenoids, and Blowback Option without COe Zero Function” <sectionnum>, steps 2 through 5.
2. Connect a clean, dry, instrument-quality supply of air (20.95% O
2
) to the 45 psig and 55 psig pressure
regulators. The inlet to the 45 psig regulator accepts a 1/8" NPT fitting. The inlet to the 55 psig regulator
accepts a 1/4" NPT fitting.
3. See the upper leg of the instrument air supply. Connect the output of the 35 psi regulator/filter to one port of
the normally-closed air-operated solenoid valve, and to the inlet side of the dilution air flow meter.
4. Connect the dilution air flow meter output to the DILUTION AIR inlet fitting on the sensor housing.
5. Install an instrument air line between the open port of the normally-open air-operated solenoid valve and the
tee fitting on the sensor housing.
6. Connect the output of the 55 psi regulator/filter to one port of the normally-open air-operated solenoid
valve, and to the instrument air inlet on the back of the electronics housing.
7. Install an air line between the open port of the normally-closed air-operated solenoid valve and the check
valve inlet fitting on the sensor housing.
8. Install an air line between the instrument air outlet fitting on the electronics housing and the control air inlet
fitting on the air-operated solenoid valve.