Honeywell P520 Manual Do Utilizador

66-2066—01

8

change the displayed value. Once the desired value is 

displayed, press the STORE button. When the set point is 

stored, four dashes are displayed momentarily, indicating that 

the new value was stored into the EEPROM. Illogical settings 

are not accepted; A display of four “E’s” when the STORE 

button is pushed indicates that an error was made when 

selecting the set points. For instance, selecting a flame out set 

point that is equal to or greater than the flame on set point will 

result in this error indication.

The set points can also be selected remotely through the 

serial communication port using a host computer.

Only adjustment information pertinent to the attached viewing 

head(s) will be visible to the user; for a UV only viewing head, 

no IR GAIN or IR FILTER settings would be shown and for an 

IR only viewing head, no UV GAIN setting would be shown.

To change or adjust any of the 3 additional setpoints shown in 

Table 3, refer to the programming flowcharts towards the back 

of this manual. IR gain adjustments are covered in the next 

section as well.

The adjustable range for IR Gain is 0-699 with a factory 

default value of 450. When adjusting IR gain, the user will 

notice gain “jumps”. As the gain is increased, the user will 

notice the following:

a. 000 – 099 is linear and then it jumps to 150

b. 150 - 199 is linear and then it jumps to 250

c. 250 - 299 is liner and then it jumps to 350

d. 350 - 399 is linear and then it jumps to 450

e. 450 - 499 is liner and then it jumps to 550

f. 550 - 599 is linear and then it jumps to 650

g. 650 - 699 is linear

With each step change or “jump”, the gain is double but values 

in between are liner. For example, a setting of 250 doubles the 

gain setting of 150. When gain is adjusted to 000, the IR 

contribution is zero. 

There are 8 high pass filter settings available for most IR 

viewing heads (model dependent) as shown below.

1 = 16 HZ

2 = 24 HZ

3 = 33 HZ

4 = 52 HZ

5 = 75 HZ

6 = 100 HZ

7 = 155 HZ

8 = 215 HZ 

The flame failure response time, or F.F.R.T., is defined as the 

time it takes for the flame relay to de-energize after the flame 

signal (from the viewing head) is below the programmed 

Flame Off setpoint. This time delay is programmable from 

both the front panel of the P520 and a remote, host computer. 

Only three settings are possible: one, two and three seconds.

The maximum time delay is limited to three seconds in 

compliance with the FM (Factory Mutual) limit of the F.F.R.T. to 

be less than four seconds.

The standard remote meter output has a 0-20mA range and is 

designed to drive remote meters, as explained earlier in this 

manual. You can convert this output to a 4-20mA range, as 

follows:

Press the front panel push-buttons (indicated in Table 4) while 

holding down both the up arrow and down arrow buttons. 

Press all buttons in each row together (i.e., three in the first 

row, two in the second row, and three in the last row).

Doing this toggles the function back and forth between the 0-

20mA and 4-20mA ranges.

The change will be verified by four dashes “----” and “4-20” 

momentarily displayed. If the signal processor is programmed 

for the 4-20mA range, “4-20” will be displayed; toggling back 

to the 0-20mA range will again cause four dashes to appear 

on power-up of the unit. The factory default setting is 4-20.

The 4-20mA signal from the P520 is powered from the P520 

itself. When sending the signal to a remote device (such as a 

distributed control system, PLC or burner management 

system), the input must be isolated. If there is a ground 

potential difference between the two systems, then there 

could be noise and performance problems. When using a 

remote meter by itself, this will not occur, because it will not be 

tied into another electrical system (will not be sharing 

grounds).

The bargraph reading on the front panel will not be affected by 

this change to 4-20mA output. It will remain the same as 

before (i.e., show zero on no signal detected). The 4-20mA 

output will still perform the same way on the high end (i.e., on 

a strong signal, it will saturate at the same level, slightly above 

22mA).

Specifications for the analog current output signal are 

provided in the SPECIFICATIONS section.

IR GAIN

3 DIGIT NUMBER

0-699

IR FILTER

1 DIGIT NUMBER

1-8

UV GAIN

2 DIGIT NUMBER

0-99

X

X

X

X

X

X

X

X