Viessmann Vitocrossal 300 CA3 2.5 Installation And Service Instructions Manual page 79

Vitocrossal 300 CA3 Series 2.5 to 6.0 Installation/Service
Safety Instructions
Menu item "6" is used to change the following operating parameters: (see page 190 for more detail)
Sub-menu Parameter
Item
1 Maximum operational input
2 Gas type
3 Not assigned
4 Maximum boiler water temperature
5 Integral threshold value of controller
6 Runtime optimization
0 Reset all operating parameters to their
factory set condition.
(continued)
General Service Information
Note: Each boiler section is equipped with its own fixed
high limit. Each fixed high limit must be tested
individually.
Fixed High Limit test procedure:
1. Use the emission test switch on each boiler section
to generate call for heat.
Refer to Vitocrossal 300 CA3 Operating
Instructions.
2. As described in the table on page 190, adjust item #4
"Max. boiler water temperature" under menu 6 of each
burner control (GC310) to a max. setting of 243°F
(117°C), as an example, higher than fixed high limit
temperature setting [factory default setting is 203°F
(95°C)].
For testing of the adjustable limit 'Max. boiler
temperature' for a reduced temp. value as required
[e.g. 122°F (50°C)].
3. Press/activate emission test switch of the applicable
boiler section, the burner will start.
4. Gradually and slowly throttle the water flow to the
boiler.
5. Observe temperature on the relative GW6C service
display.
6. Once the temperature reached the fixed high limit
setting, burner control will have a hard lock out with
F F1 fault displayed. Burner fan stays on for 10 min.
The fault can only be manually reset once the water
temperature in the boiler drops.
7. Reset to original settings as needed (item #4 under
submenu 6).
Units/Scale
% of rated input
0=NG (natural gas)
1=LPG (liquid propane gas)
--
from 41°F to 260°F (5°C to 127°C)
In Kmin from 1 to 255
0=minimum pause
1=integral method
--
Factory set
condition
100%
0
--
203°F (95°C)
30 Kmin
1
--
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