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Series 8900SH Control Panel Operation And Installation Manual
Section 8 Entry Code Details
every 1°F the outside temperature drops, the Return Water Line temperature is increased 1°F.
If the ratio is set at 1.50, the Return Water Line will increase 1.5°F for every 1°F drop in
outside temperature.
THE FORMULA BELOW WILL HELP YOU DETERMINE THE INITIAL RATIO SETTING.
Outdoor Reset Ratio Formula:
Design Return Water Temperature – Minimum Return Water Temperature
= Outdoor Reset
Outside Shutdown Temperature – Outside Design Temperature Ratio
Example:
180°F - 100°F
= 80°F = 1.14 Reset Ratio
60°F - (-10°F) 70°F
ENTRY CODE 24: RATE OF CHANGE FACTOR
PRESS + = ENTRY CODE
ENTER YOUR CHOICE
PRESS = SAVE KEY, FOR A RATE OF CHANGE FACTOR OF .10.
THE AVAILABLE RANGE IS FROM .01 TO 2.00
This code allows you to set the speed of the counter that was explained in code 17. The Rate
of Change Factor directly influences how fast or slow boilers are brought on line when heat is
called for. If boilers are brought on line too quickly, a waste of fuel can result due to too many
boilers running and short-cycling. Too long a count between boilers may result in
unsatisfactory heat to the building. TRIAD recommends an initial setting of .10. The lower the
factor, the longer (slower) the response time of the boilers, and the higher the factor, the
shorter (faster) the response time.
ENTRY CODE 26: NUMBER OF BOILERS TO BE CONTROLLED
PRESS + = ENTRY CODE
ENTER YOUR CHOICE
PRESS = SAVE KEY, TO CONTROL 24 BOILERS.
THE AVAILABLE RANGE IS FROM 1 TO 24
2
4
.1
0
#
2
6
2
4
#