ABB Endura AZ20 series

Combustion Oxygen Monitor
Endura AZ20 Series Probe 5 Dismantling and Reassembly – Probe
32 IM/AZ20M–EN Rev. B
Referring to Fig. 5.17:
8. Withdraw the thermocouple / electrode assembly out of
the inner assembly by approximately 50 to 70 mm (2 to
2.8 in.).
9. Carefully slide the inner assembly
G into position.
10. Re-position the thermocouple / electrode assembly and
secure it in position – refer to Section 5.8.2, steps 13 and
14, page 22.
11. Secure the internal mounting plate to the probe body
using the 3 M4 screws
H using the 3 mm A/F hexagon
wrench (supplied).
12. Remove the 2 barbed test gas connectors I and
replace them with the 2 connectors and seals supplied. If
necessary, use PTFE tape to ensure a leak-tight joint.
13. Re-connect the thermocouple / electrode assembly wires
to the 9-way terminal block
J (inner terminals) as shown
in Table 5.2:
14. Connect the screen from terminal SCN connection to the
internal earth connection
K.
15. Make AutoCal cable connections to the 6-way terminal
plug L as shown in Table 5.3:
Caution. Test gas is applied to the probe
continuously on AutoCal models. All connections
through to the AutoCal assembly inside the probe
must be leak-tight to prevent loss of test gas and
contamination of reference air within the probe which
could result in incorrect reading.
Terminal / Cable Color Type Tx Connection
Red Cell +
Oxygen
Input (+ve)
Green T/C+ Thermocouple (+ve)
White T/C – Thermocouple (–ve)
Table 5.2 Thermocouple / Electrode Assembly
Terminal Block Connections
Terminal / Cable
Color
Tag ID AutoCal Connection
White / Yellow PS2
Pressure Switch
Gas 2
White / Black PS COM Pressure Switch COM
White / Orange PS1
Pressure Switch
Gas 1
White / Green SV1 Solenoid Valve Gas 1
White / Red SV CO
M Solenoid Valve COM
White / Blue SV2 Solenoid Valve Gas 2
Table 5.3 AutoCal Terminal Plug Connections
Fig. 5.17 Re-positioning the Inner Assembly and Making
Terminal Plug Connections
G
H
I
J
K
L