Calculation Methods

The module provides three internal calculation methods which can be selected by parameter SYS-04. Besides the three internal calculation methods, custom programming logic can be used and connected to the input “Req_Load“. In case the input “Req_Load“ is not connected (set to value 999), the internal calculation defined by parameter SYS-04 becomes active. See next table for an overview of the calculation methods.

Table 1.   Calculation method

SYS-04

Calculation method

0

Chilled water system return temperature control

1

Chilled water system supply and return temperature control

2

Chiller capacity control


In case the input “Req_Load“ is connected to custom programming logic, the input behaviour can be defined by parameter SYS-05. See next table for an overview of the “Req_Load“ input signals.

Table 2.   Input Req_Load

SYS-05

Input Req_Load

0

Absolute value 0…N

1

Floating value –1; 0,+1

2

Modulating control signal 0…100


Table 3.   Parameter List

Description

Value Range

Default Value

Unit

SYS-04: calculation method:

0 = SRT only

1 = SST/SRT

2 = chiller capacity

0…2

0

-

SYS-05: Req_Loads input

0 = absolute 0…N

1 = floating –1; 0,+1

2 = percent 0…100

0…2

0

-