Hydromatic II Chiller Operation Manual

Table Of Contents

Page 5

System Overview

The Hydromatic system operates as a master – slave system. Each control in the

system is considered a slave. The master function can be assigned to any slave in the

system. The master function operates independently from the slave function within that

control. A slave is designated as a master by making the group ID and unit ID the same

value. Additional slaves can be added by setting their unit ID as the next numerically

higher unit ID and assigning them to the same group ID as the master. A system pump

control will also be configured during setup.

The master controls all operations once the system is configured. Individual slave

compressors are started as needed and cycled regularly to equalize run time when

possible.

Additional details on setting unit numbers may be found in Appendix 2:

Organizing IDs in the CAN system.

Operational Overview

Cooling

The first stage of cooling is started when the loop return water temperature rises

above the cooling set point by the amount programmed in the differential parameter. One

slave is selected by the master to start its compressor. If the stage is programmed to have

more than one compressor, each additional compressor will start one at a time, after the

expiration of the staging delay. Additional increases in loop return water temperature by

the amount programmed in the differential parameter will start subsequent stages until all

available stages are operating.

The first stage of cooling is shut down when the loop water temperature reaches:

(Set point + (number of active stages * differential) – hysteresis)

Differential and hysteresis is the value set by their programmable parameter value

for the above equation.

Each subsequent reduction in loop return water temperature by the amount set in

the hysteresis parameter will shut down the next stage. If the loop water return

temperature reaches the cooling set point, all compressors will shut down.

Heating

Heating operation is similar in function to cooling operation utilizing the heating

set point along with differential and hysteresis to control loop return water temperature.

If the sea water temperature drops below the temperature set in the EL Heat Transition

parameter, any operating compressors will be turned off and only electric heaters will be

used to heat loop water. The heaters will be used for the remainder of the cycle even if

the sea water temperature increases above the electric only temperature set point. Electric

heaters must be available and the optional sea water sensor installed for this function.