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MUTLI-UNIT PRIMARY
On installations having multiple Water to Water Source Heat
Pumps serving a common load, the heat pumps may be controlled
as a singular heating or cooling source utilizing the Multi-unit
MS/TP Operating Mode.
For these installations, the modules are networked together. One
of the installed Water to Water Source Heat Pumps operates as a
Primary control, with the remaining modules operating as
Secondary. Configured thus, the number of stages required to meet
load conditions are determined by the Primary control. Secondary
modules will receive the number of stages required from the
Primary, and will energize their compressor outputs appropriately
in sequence.
In this fashion, a Multi-unit MS/TP system can provide for up to
eight total stages of control. A Multi-unit MS/TP system will
provide coordinated heat pump operation with the same feature set
and sequences of operation as that provided by a Single Unit
configuration.
In this configuration, an independent leaving load water
temperature safety check at each unit is included to verify that
sufficient load water flow is provided. Should the leaving load
water temperature fall below the configured "Chilled Water
Setpoint" in cooling or the "Hot Water Setpoint" in heating, the
compressor stages for any unit (primary or secondary) will be re-
duced as needed without reducing the system staging require-
ments.
IMPORTANT: Be sure to configure each secondary unit for
standalone operation as a fail-safe. Many individual
configuration parameters that are not required or used during
secondary operation such as the chilled water and hot water
setpoints are hidden once the secondary is linked to a primary
unit.
EQUIPMENT ALARM
The W2W provides an alarm output that will illuminate an
equipment mounted alarm lamp, and generate a generic
Equipment Alarm under certain alarm conditions configured by an
operator. See the Equipment Alarm configuration section for
configuration instructions related to Equipment Alarm.
SERVICE TEST
The W2W provides a built in Service Test function to allow the
installing technician a means to test the modules process outputs
independently.
1.
The Isolation Valve Test energizes the control's Isolation
Valve Binary Output.
2.
The Water Pump Test energizes the control's Water Pump
Binary Output.
3.
The Compressor Test energizes the control's Compressor
Binary Outputs.
4.
The Alarm Indicator Test energizes the control's Alarm
Indicator Binary Output.
Invoking the Service Test function will disable normal equipment
operation. Service Test will operate in accordance with the
control's configuration. For example, initiating the Compressor
Test function of Service Test on a two-stage heat pump configured
to provide both heating and cooling will energize the stages of
compression in sequence; first staging up in Cooling, then
changing the reversing valve before staging down in Heating.
Although the isolation valve and water pump outputs may be
tested independently, they will be automatically energized when
the Compressor Test is enabled.
Service Test will time out (disable) automatically after 60 minutes
should the technician neglect to disable it after completing the test.
Invoking the Service Test function will disable normal equipment
operation. Service Test will operate in accordance with the
controls' configuration. For example, initiating the Compressor
Test function of Service Test on a two-stage heat pump configured
to provide both heating and cooling will energize the stages of
compression in sequence; first staging up in Cooling, then
changing the reversing valve before staging down in Heating.
Although the isolation valve and water pump outputs may be
tested independently, they will be automatically energized when
the Compressor Test is enabled.
Service Test will time out (disable) automatically after 60 minutes
should the technician neglect to disable it after completing the test.
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