General Information
Hot Water control
Occasionally CTV chillers are selected to provide heating as a primary mission. With hot water temperature control, the chiller can be used as a heating source or cooling source. This feature provides greater application flexibility. In this case the operator selects a hot water temperature and the chiller capacity is modulated to maintain the hot water setpoint. Heating is the primary mission and cooling is a waste product or is a secondary mission. This type of operation requires an endless source of evaporator load (heat), such as well or lake water. The chiller has only one condenser.
Note: Hot water temperature control mode does not convert the chiller to a heat pump. Heat pump refers to the capability to change from a cooling- driven application to a
This is NOT heat recovery. Although this feature could be used to recover heat in some form, there’s not a second heat exchanger on the condenser side.
The DynaView™ Main Processor provides the hot water temperature control mode as standard. The leaving condenser water temperature is controlled to a hot water setpoint between 80 and 140°F (26.7 to 60°C) The leaving evaporator water temperature is left to drift to satisfy the heating load of the condenser. In this application the evaporator is normally piped into a lake, well, or other source of constant temperature water for the purpose of extracting heat.
In hot water temperature control mode all the limit modes and diagnostics operate as in normal cooling with one exception; The leaving condenser water temperature sensor is an MMR diagnostic when in hot water temperature control mode. (It is an informational warning in the normal cooling mode.)
In the hot water temperature control mode the
UCP provides a separate entry at the DV to set the hot water setpoint. Tracer is also able to set the hot water setpoint. In the hot water mode
the external chilled water setpoint is the external hot water setpoint; that is, a single analog input is shared at the 1A16
An external binary input to select external hot water control mode is on the EXOP OPTIONAL module 1A18 terminals
There is no additional leaving hot water temperature cutout; the HPC and condenser limit provide for high temperature and pressure protection.
In hot water temperature control the softloading pulldown rate limit operates as a softloading pullup rate limit. The setpoint for setting the temperature rate limit is the same setpoint for normal cooling as it is for hot water temperature control.
The hot water temperature control feature is not designed to run with HGBP, AFD, or ice making.
The factory set PID tuning values for the leaving water temperature control are the same settings for both normal cooling and hot water temperature control.
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