4.28 Boiler temperature limiting with burner control
Boiler temperature can be limited with burner control. It can be implemented with the
same sensor used for temperature control, or with a separate sensor. When pressure
control is selected, temperature limiter is not in use.
If limiter temperature switch-on point is reached, burner shuts down. Burner restarts
when temperature limiter is reset.
Example:
TL_ThresholdOff
Limiter switch-on point
176 °F
TL_SwiDiff_On
Temperature difference percentages
-10 % (46.4 °F)
Limiter reset temperature
161.6 °F
Description
Params. & Display
LoadController
TempLimiter
TL_ThreshOff
Temperature limiter
OFF threshold, °F
TL_SD_On
Temperature limiter
switching differential
ON
4.29 Cold start thermal shock protection
Cold start thermal shock protection protects the boiler from thermal stress if the boiler
has cooled down. The burner starts with small load and the load increases as the boiler
warms up. Without protection, the burner runs straight to full load.
If boiler temperature or pressure has dropped under set value
ThresholdOn
, the burner
starts with minimum load. The load depends on two factors:
1. If the set value does not reach the set step within the maximum time, the load will
be increased by one stage step.
2. If the set value has reached the set step before the maximum time has elapsed, the
load increases by one stage step.
The menu shows values used in the chart example.
Example,
Set value 145 PSI
Params. & Display
LoadController
ColdStart
ColdStartOn
activated
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M4248 2316EN
