Product Overview

© Danfoss | DCS | 2019.04
Data sheet | Superheat controller type EKE 1A, EKE 1B, EKE 1C
DKRCC.PD.RS0.A4.02 | 50
Danfoss 80G8305.10
TT
S2
EEV
P
18.3 Compressor feed
forward SH reference
EKE 1A 1B 1C
Applicable
-
When a compressor speed changes, system dynamics change correspondingly. An adaptive controller
is preferred to meet the control performance requirement on both functionality and safety.
Feed forward compressor speed implemented in EKE controllers acts as an advantageous functionality
to handle such situations.
When a compressor speeds up or slows down, evaporating pressure will change immediately which
results in increase or decrease of superheat respectively. Feed forward compressor speed function
will auto tune the PI control values to react according to the new change conditions to meet the
control performance as well as safety.
To use this feature bus communication is needed and the master controller must send the feed
back of the compressor speed to EKE controller.
Note:
This function is basically used
in one to one systems and
requires a modbus to feed the
compressor speed. This
functionality may not be used
in multi-evaporator system.
Compressor speed signal via MODbus
Master
control
Parameter Function Description
N135 Comp. speed feed forward function 0 = O | 1 = On, default O
R100 Compressor Capacity compressor capacity value in percentage via Modbus
N136 FF low capacity turning point
The point where sh control is starting to slow. Below this speed
superheat control is slower
N137 FF maximum factor for Tn turning
The maximum add to the integration time. At 0 % the TN = normal
Tn * Comp FF SH Tn factor
Where to use:
This feature is typically using in VSD system. This can also be use in multi stage compressor.
The system controller must send the compressor capacity % value over modbus.