Emerson Process Management OXYMITTER 4000 - Manual (Page 64)

Instruction Manual
IB-106-340C Rev. 4.1
July 2004
3-2 Configuration with Keypad Rosemount Analytical Inc. A Division of Emerson Process Management
Hazardous Area Oxymitter 4000
c. Verify Hazardous Area Oxymitter 4000
Configuration
Located on the microprocessor board, the
top board, are two switches that configure
outputs for the Hazardous Area Oxymitter
4000 (Figure 3-2). SW1 determines if the
4-20 mA signal is internally or externally
powered. SW2 determines:
The HART option is not protected by
energy limiting barriers. It must not be
interfaced from within the hazardous
area. The 4-20 mA cables should be
routed and the connections made out-
side the hazardous area. Note that this
is the case even when using the intrin-
sically safe version of the handheld
communicator.
1. Hazardous Area Oxymitter 4000
status, HART or LOCAL.
2. Oxygen range, 0 to 10% O
2
or 0 to
25% O
2
. (0 to 40% O
2
is also configur-
able only through HART/AMS.)
3. The 4-20 mA signal, at fault or power
up, 3.5 mA or 21.6 mA.
Remove power from the Hazardous
Area Oxymitter 4000 before changing
defaults. If defaults are changed under
power, damage to the electronics
package may occur.
d. SW1
The two settings are internally or externally
powering the 4-20 mA signal. The factory
setting is for the 4-20 mA signal to be inter-
nally powered.
e. SW2
The factory sets this switch as follows:
1. Position 1 is HART/LOCAL. This switch
setting controls the configuration of the
Hazardous Area Oxymitter 4000. The
defaults cannot be changed via HART-
/AMS unless the switch is in the HART
position. Placing SW2, position 1 in the
LOCAL position forces the O
2
range to
the setting of position 2. The position 1
switch must be placed in the LOCAL
position or changes in SW2, position 2
will have no effect.
2. Position 2 determines the O
2
range.
This can be set to either 0 to 10% O
2
or 0 to 25% O
2
. The factory setting is
0 to 10% O
2
.
Typically, the probe’s sensing cell, in
direct contact with the process gases,
is heated to approximately 736°C
(1357°F). The external temperature of
the probe body may exceed 450°C
(842°F). If operating conditions also
contain high oxygen levels and com-
bustible gases, the Hazardous Area
Oxymitter 4000 may self-ignite.
If necessary, the O
2
range can be con-
figured from 0 to 40% O
2
. To select
values within this range, set SW2,
position 1 to HART and then enter the
range via HART/AMS. Do not change
SW2, position 1 to LOCAL unless you
want to operate in the range specified
by SW2, position 2.
3. Position 3 determines the output at
startup or at an alarm. The settings are
3.5 mA or 21.6 mA. The factory setting
is 3.5 mA. At startup, the current at the
analog output is 3.5 mA or 21.6 mA.
4. Position 4 can be used to set the
heater for 115 or 220 Vac operation.
This switch is functional only when the
software is set for manual voltage
selection (Auto Tune = No). Otherwise,
the internal electronics auto detect the
input line voltage and sets the heater
voltage accordingly (Auto Tune = Yes).
f. Once the cell is up to operating tempera-
ture, the O
2
percentage can be read: