ABB Endura AZ20 series

Combustion Oxygen Monitor
Endura AZ20 Series Probe 5 Dismantling and Reassembly – Probe
22 IM/AZ20M–EN Rev. B
5.8.2 Fitting a New Thermocouple / Electrode Assembly
Referring to Fig. 5.8:
1. Remove the existing spring locator
A from the old
assembly.
2. Lay the new assembly B out at the end of a long work
surface and carefully uncoil the electrode wires, one at a
time.
3. Fit the 500 mm (19.7 in.) long insulator(s)
D supplied –
refer to Table 5.1 for insulator quantities for each probe
length.
Thread each insulator onto the extension wires one by
one. Ensure wires are not crossed in the insulator
channels. Do not attempt to thread more than half the
insulator length onto a wire at one time and ensure
insulators butt together correctly at the joints.
4. Next fit the (short) 148 mm (5.8 in.) insulator
E.
5. Identify the thermocouple negative wire (TC–) F
(magnetically attractive). The thermocouple positive (TC+)
G is the same wire diameter as the thermocouple
negative (TC –)
F. The thinnest wire is the cell positive
(Cell+) H.
6. Using the correct PTFE colored sleeving (supplied), slide
each sleeve onto the wire ends I:
– Green (TC+), thick wire, non-magnetic
G
– White (TC–), thick wire, magnetic F
– Red (Cell+), thin wire H
7. Pass 100 mm (4 in.) of sleeving into the last (short)
insulator
E.
Note. To retain the uncoiled lead ends during fitting,
use a clamping block C constructed from a wooden
board and 3 bulldog clips or use 3 weights.
Caution. Do not kink the wires during fitting as they
will not feed through the insulators if kinked.
Insertion
Length m (ft.)
No. of
Insulators
Insertion
Length m (ft.)
No. of
Insulators
0. 5 (1.7) 0 2.5 (8.2) 4
1.0 (3.3) 1 3.0 (9.9) 5
1.5 (5.0) 2 3.5 (11.5) 6
2.0 (6.6) 3 4.0 (13.1) 7
Table 5.1 500 mm (19.7in.) Insulator Requirements by
Probe Length
Caution Do not trim the sleeves – they must pass
into the last insulator by 100 mm (4 in.) to ensure that
the wires cannot short out when operating at very
high process temperatures due to thermal expansion
differences.
Fig. 5.8 Disassembling the Thermocouple / Electrode Assembly
and Fitting New Insulators
C
E
H
F
G
A
D
B
E
I
4
5
0
m
m
(
1
7
.
7
in
.
)
S
le
e
v
e
450 mm (17.7 in.) Total
Sleeve – including 100
mm (4 in.) within insulator
Pass Sleeve
100 mm
(4 in.) inside
insulator
2 Electrode
Contact
Springs