Yokogawa AC8 Calibration Units - Manual (Page 13)

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IM 11M06D03-01E-A
VI. INSTALLATION, AUTOMATIC CALIBRATION, AC1
6.1 LOCATION
The following guidelines should be used when selecting a location for the calibration unit:
1) Easily accessible for maintenance and inspections.
2) As close to the ZR22 probe as practical. This will minimize the amount of tubing required for plumbing, and
decrease calibration times. Ambient temperature should not exceed 55˚C (131˚F).
3) Humidity is moderate and no corrosive gases are present
Use an air purge for the AC1 enclosure if the corrosive gases or high dust content is present.
4) Minimal vibration
5) Clean, dry instrument air is available
6.2 MOUNTING THE AC1
The AC1 is available in a NEMA and NEMA 4X, lockable enclosure, and the unit is designed for wall mounting. It can
be secured using four (4) standoffs and four (4) bolts. Mount the AC1 unit so that the terminal strip is easily visible for
wiring purposes. Sufficient room should be made available for connecting the calibration and reference gas tubing.
The unit must be mounted as level as possible to ensure the accuracy of the flow rates
6.3 PIPING
A list of recommended part for piping to the MC1 and AC1 units is listed previously in Table 4.1
6.3.1 PIPING TO THE ZR22G OXYGEN PROBE
6.3.2 CONNECTION TO THE CALIBRATION GAS INLET
Connect the tubing from the Zero (cal) gas output, shown in Figure 5.1, to the CAL IN side of the ZR22 probe. If the
process is a positive pressure application, ensure that a check valve (Yokogawa Part Number M1234VV-A) is
installed between the CAL IN port and the 1/4” tubing. The check valve may already be installed on the detector
prior to shipping.
6.3.3 CONNECTION TO THE REFERENCE GAS INLET
Connect the tubing from the Reference gas output, shown in Figure 5.1, to the REF IN side of the ZR22 probe.
Clean, dry instrument air is recommended as a reference (span) gas; however, ambient air may be used as a
substitute.
6.4. WIRING TO THE AC1, AUTOMATIC CALIBRATION UNIT
6.4.1 WIRING THE AC1 TO THE ZR22G
The solenoids of the AC1 are powered by 24VDC from the ZR402G Oxygen Converter. The AC1 itself can be
powered by the ZR402G if the ZR402G is using 120VAC, 60Hz. Supply voltage for the AC1 can be obtained from
terminals “L, N & G” on the ZR402G. Please refer to the wiring diagram located in Appendix C.
NOTE
NOTE