Honeywell 800 Series Manual page 16

HONEYWELL MODEL 700/800 SIGNAL PROCESSOR AND VIEWING HEAD
The 0/4-20mA output option is live; the operative range
changes as soon as the displayed selection is changed.
However, the value must still be saved via the STORE
button in order to be saved in the signal processor's
EEPROM.
To exit the menu at any time without saving changes,
simply press the RESET/rE button or wait four seconds.
The analog current output is scaled according to the
RELAY ON setting. It is scaled so that, if the counts
coming in are at a count rate equal to the RELAY ON
setting, the current output is approximately 13 MA when
the range selected is 0-20 MA, and about 14.6 MA when
the range selected is 4-20 MA.
Note that the actual maximum level for the current output
is 19.8 MA.
Automatic Setup of Setpoints
With this feature, the Model 700 signal processors set the
RELAY ON SET POINT, the RATIO % (Relay Off), and the
UV/IR GAIN automatically. Calculations for these settings
are carried out in the signal processor as the operator
takes the system through BURNER ON and BURNER OFF
sequences. Fig. 20, 21 and 22 flowchart the automatic
setup sequence.
The FFRT (flame failure response time) and the 0/4-20mA
output option must be manually setup after the automatic
setup process is complete. Refer to the Manual Setup of
Setpoints section and Fig. 25 and 26. for details on setting
these 2 parameters.
Before starting the automatic setup sequence, adjust the
RELAY ON SET POINT to get the FLAME ON relay to
energize.
Press BNR-ON SEQ START/END key for two seconds. If the
FLAME ON relay is de-energized, the display will show
"bo" (burner off); press RESET to clear this. If the FLAME
ON relay is energized, the ON SEQ LED will start flashing
slowly and the numeric display will start counting down
from 59 while the processor takes data at one reading per
second. The FLAME ON relay will remain energized if the
flame is present, according to the current settings, until
valid new values are obtained. To end the data sampling,
press the same button, BNR-ON SEQ START/END, again,
but ensure that an adequate number of data samples has
been taken. At least 30 seconds of BNR-ON data sampling
is recommended; ten seconds is a minimum. The software
will not respond to a second press of the button for 10
seconds. RESET may also be pressed while the data
sampling is occurring; the data sampling process will be
aborted and the old values will remain in effect.
After BNR-ON data sampling is complete, the OFF SEQ
LED flashes. Turn off the burner and immediately press
the BNR-OFF SEQ START/END key (a two-second press is
not required). The displayed timer then counts down from
29. This process may be interrupted, but at least 15 seconds
of BNR-OFF data sampling is recommended. The data
sampling process can be aborted by pressing RESET, in
which case the data for both BNR-ON and BNR-OFF will be
discarded and the previous values will remain in effect.
66-2069EP—08
If the data is good, that is, the computed ratio is 71% or less
when BNR-OFF data sampling is complete, the display
shows the ratio in percentage for one second, followed by
"- -" to indicate a successful setup. The signal processor then
turns on the AUTO SET LED to verify that the values stored
internally were derived from the BNR-ON/BNR- OFF data
sampling sequence.
If the data received is marginal, with the computed ratio
ranging from 72% to 80%, the display alternates between
"AC" and the computed ratio, for example, "AC" and "75."
Press either the ACCEPT RATIO or RESET keys. If ACCEPT
RATIO is pressed, the display responds with "- -", the ratio
is stored, and the AUTO SET LED is turned on. If RESET is
pressed, the display returns to the counts, both of the AUTO
SETUP LEDs are turned off, and the old setpoints are used.
If the ratio computed as a result of BNR-ON and BNR- OFF
data sampling is higher than 80%, the display will show
"UA" (unacceptable), alternating with the unacceptable
ratio. For example, if the computed ratio is 93%, the
display would alternate between "UA" and "93." RESET
must be pressed to clear this; the old values for RELAY ON
and RATIO will remain in effect.
The values can be worse than just unacceptable. If the
flame relay de-energizes while reading BNR-ON values,
the display will show "bo," and data-taking will be aborted.
Other faults, such as a BNR-ON flame signal that is too low
to use, or BNR-OFF readings that are too close to the
BNR-ON readings, can result in "rE" being displayed.
RESET should then be pressed.
The signal processor also adjusts the viewing head gain
during the BNR-ON and BNR-OFF data sampling
sequence. Normally, after the sequence, the display
should read about 20, because the gain has been adjusted
to give this reading. If it is less than about 18, you should
find that the gain has been set to 9; if it is more than about
22, you should find that the gain has been set to 1.
Once the values have been stored through this sequence,
you can check the RELAY ON SET POINT, the RATIO, or the
GAIN by pressing the appropriate key for two seconds.
However, if you attempt to change these values by
pressing the INCREASE or DECREASE keys, the display
will show "CF" (confirm), and the AUTO SET LED will flash
rapidly. To confirm the desired change, press the RELAY
ON SET-POINT key, the RATIO key, or the SET GAIN key a
second time. To discontinue any changes, press the
RESET key or simply wait four seconds for a time out to
occur.
The user confirms they wish to make changes, the values
will change when you use the INCREASE or DECREASE
keys. Meanwhile, the AUTO SET LED will be flashing. The
AUTO SET LED will de-energize only if the changed values
are stored; if the changed values were not stored, the
AUTO SET LED will light and the old values will remain in
effect.
If values were obtained automatically, that is, if the AUTO
SET LED is on and the BNR-ON SEQ START/END key is
pressed, the display will also show "CF." If the BNR-ON
SEQ START/ END key is pressed again, the signal
processor will begin the BNR-ON data sampling
sequence.
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