Raychem HWAT-ECO Mode D'emploi page 25

pipe sizes results in lower temperatures as the heat losses increase.
The HWAT-ECO internal data is based on standard sets of values for pipe
size and insulation characteristics. Any deviations from these standard sets
will result in a deviation from the target temperatures. The unit compensates
for this by using the 'Power Correction Factor'.
Pipe / Insulation combination
The country code must be entered in order to refer to an insulation thick-
ness typical used in a concerned country.
Two groups of countries depending on insulation thickness (See table in 5.1)
The HWAT-ECO assumes a default 25 mm pipe diameter ('Quick Install').
It is recommended to use the appropriate insulation type in case another
pipe size is needed, otherwise bigger temperature deviations may occur.
Installations with varying pipe diameters
If the HWAT circuit is maintaining a piping system comprising different pipe
sizes (and assuming similar insulation materials and appropriate thickness),
a compromise pipe size should be selected:
• Thinner pipes will run hotter, thicker pipes will run cooler if average
pipe size is selected.
• The minimum pipe size should be selected if the maximum tempera-
ture should be limited (for safeguarding against scalding).
• Thinner pipes will run hotter if maximum pipe size is selected.
Installations with deviating pipe size – insulation combinations (Fig. 9)
In case different combinations of pipe size and insulation dimensions are
used, it is possible to compensate for temperature deviations by using the
'Power Correction Factor'. (See page 17, chapter 3.2 Setup, Power corr.)
This factor is able to compensate for up to a few degrees. Lowering the fac-
tor (down to 60%) will decrease the temperature, increasing the factor (up
to 140%) will increase the temperature. As the 'Power Correction Factor' can
compensate for only a few degrees, it is not advised to use pipe size – insu-
lation type combinations varying appreciably from the combinations given in
the table below.
Note: Increasing the 'Power Correction Factor' does not result in further
temperature increase when the HWAT-ECO is set to maintain temperatures
close to the maximum temperatures achievable with a given heating cable
type.
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