Built-In Dhw And Space Heating Control (Hdc) - Carrier 30WG Operation Instructions Manual

8.11 - Built-in DHW and space heating control (HDC)

30WG/61WG units with Heating Device Control are specially
designed to optimise the operation of heating installations
that require hot-water production for traditional heating and
domestic hot water (DHW) requirements. In this case an
AUX board is included in the unit control box.
The Touch Pilot J. control of the 30WG/61WG includes
algorithms that permit constant and automatic optimisation:
• Control of a three-way directional on/off valve based
on the heating or domestic hot water requirements
(3-way valve used to switch between Space Heating
and Domestic Hot Water).
• Control of the electric heater stages can complement the
heating loop (booster heater), 1 to 4 electric heating stages.
• Hot water setpoint reset (heating units) based on the
outside air temperature (weather compensation function).
• Priority control between heating and domestic hot
water applications.
8.11.1 - Sensor
Outside air temperature sensor can be used to reset the
setpoint or determine the summer/winter mode.
The control point is reset with a value calculated according
to the outdoor air temperature reading.
8.11.2 - User connection terminals
Three volt-free contacts are available at a user connection
terminal board.
• A contact for DHW demand from the tank.
• A volt-free contact for DHW priority.
• A volt-free contact for the summer mode.
8.11.3 - Control of electric heater stages
The unit can control up to four electric heater stages as
supplementary heating.
Electric heater stages are activated to supplement the heating
capacity under the following conditions:
• The unit uses 100% of its available heating capacity or
the unit is limited in its operation by a protection mode
(e.g. low suction temperature protection) and in all
cases cannot satisfy the heating demand.
• The.outside.temperature.is.below.a.configurable.
threshold.defined.in.the.Heat/Cool.Configuration.menu.
(HCCONFIG).
• Unit demand limitation is not active.
To set Electric heating stage OAT threshold
1..Navigate.to.the.Configuration.menu.
2. Select Heat/Cool Config (HCCONFIG).
3. Set Elec Stage OAT Threshold [ehs_th].
Elec Stage OAT Threshold [ehs_th]
-5 to 21°C 5°C
If. required,. the. user. can. configure. the. last. electric. heater.
stage available as a safety stage. That safety stage is only
activated in addition to the other stages if there is a unit fault
that prevents the use of the heating capacity. The other electric
heater stages continue to operate as described earlier.
The electric heater stages operate only in the heating mode,
but not during domestic hot water production.
8.11.4 - Heating or domestic hot water mode
A three-way valve permits switching the heating capacity to
a domestic hot water tank.
The unit requests changeover to the domestic hot water mode
if all of the following conditions have been met:
• The volt-free tank request contact is closed.
• Time schedule 3 is occupied (DHW mode requested) OR
the volt-free priority contact (DHW priority) is closed.
Based on the operating mode the water setpoint is adjusted:
• In heating mode, setpoints hsp1 and hsp2 are used.
They.can.be.modified.by.user.reset.or.based.on.OAT.
• In domestic hot water production mode setpoint hsp3
is used. No setpoint reset is used.
The unit requests changeover to the heating mode if at least
one of the following conditions applies:
• The volt-free tank request contact is open.
• The.max..duration.in.the.DHW.mode.has.finished.
• Time schedule 3 is in an unoccupied period
(DHW mode not requested).
If a mode change is requested while a compressor is operating,
it is stopped before the three-way valve changes to the new
mode, and then the unit is re-started.
If the unit is in domestic hot water production mode, a "DHW"
message ("DHW running") is displayed on the user interface
next to the current operating mode.
8.11.5 - Summer mode
The Summer mode is used to control DHW mode. When the
Summer mode is active (space heating is not required) the unit
can start the water tank to provide hot domestic water.
The Summer mode is activated when the Summer switch is
closed.OR.outdoor.air.temperature.exceeds.the.predefined.
Summer.OAT.threshold.for.a.specific.time.period.(start.delay)..
The Summer mode is deactivated when the Summer switch is
open OR outdoor air temperature is below the Summer OAT
threshold.for.a.specific.time.period.(stop.delay).
To verify Summer switch status
1. Navigate to the Main menu.
2. Select Heating Device (HDC_STAT).
3. Verify Summer Switch [SUMM_SW].
Summer Switch [SUMM_SW]
open/closed open = mode inactive; closed = mode active
To set Summer OAT threshold and start/stop delay
1..Navigate.to.the.Configuration.menu.
2. Select HDC Configuration (HDC_CONF).
3. Set Summer OAT Threshold [summ_oat].
Summer OAT Threshold [summ_oat]
15 to 30°C
4. Set Summer OAT start/stop delay [summ_on / summ_off].
Summer OAT start delay [summ_on] / ...stop delay [summ_off]
0-12 h 5 h
8.11.6 - Additional water pump
An additional water pump, installed in the heating water
circuit starts if the summer mode is deactivated.
If.the.anti-stick.function.is.configured,.the.additional.water.
pump starts periodically.
20°C
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