Danfoss EKC 316A Reference Manual page 10

When to use Single or Double loop
In most applications and especially air coolers, the single loop is
the best option because of simplicity and easier to tune.
In water chillers where the S3 sensor is located at the leaving wa-
ter outlet, the double loop gives some advantages in terms of be-
ing less susceptible to compressor or fan step changes. Further, it
gives a quicker opening of the valve during start up. However the
double loop is less advantages on air coolers of slower response of
the media temperature.
NOTE
The settings Atten.factor (address n43) and Min.Lim.Ref (address
n45) should not be changed without the help of trained staff.
The S3 sensor has to be connected when Reg.type = 3, or else an
alarm is given.
Recommended control loop type and settings for some ap-
plications
From the experience of using single loop and double regulation,
the following recommendations are given for the applications
that EKC 316A has been used in. These are only recommendations
and the final choice is made by the end user.
Application
address n56
Air cooler 1 (Single loop)
Water chiller 3 (Double loop)
10
Reg. type Kp factor
address n04
3.0
0.7
Reference manual RS8ED102 © Danfoss 03-2006
Tn sec Kp T0
address n05 address n20
120 0.4
120 2.0
TnT0 sec
address n44
-
30
EKC 316A