ESIE10-01 Functional Control
Part 2 – Functional Description 2–33
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■ Reset Type – 4-20 mA
The Active Leaving Water variable is adjusted by the 4 to 20 mA reset analog input.
Parameters used:
1. Cool LWT set point.
2. Max Reset set point.
3. LWT Reset signal.
Reset is 0 if the reset signal is less than or equal to 4 mA. Reset is equal to the Max Reset Delta
T set point if the reset signal equals or exceeds 20 mA. The amount of reset will vary linearly
between these extremes if the reset signal is between 4 mA and 20 mA. An example of the oper-
ation of 4-20 reset in Cool mode is shown below.
■ Reset Type – OAT
The Active Leaving Water variable is reset based on the outdoor ambient temperature. Parame-
ters used:
1. Cool LWT set point.
2. Max Reset set point.
3. OAT.
Reset is 0 if the outdoor ambient temperature is greater than Start Reset OAT set point. From
Start Reset OAT set point down to Max Reset OAT the reset varies linearly from no reset to the
max reset at Max Reset OAT set point. At ambient temperatures less than Max Reset OAT set
point, reset is equal to the Max Reset set point.
Actual Setpoint
0start
ΔT on evaporato
ΔT
Max
reset
Local or Dual
Setpoint
(54)
04 20
Max Reset
(10)
Active
LWT
(°F)
Reset Signal (mA)
4-20 mA Reset - Cool Mode
Cool LWT Set
Point (44)
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