NuAire ecosmart CONNECT XBOXER XBC, Установка, Подробности Управления, Эксплуатация и Обслуживание

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7.8.3 OVERRIDES
When the following conditions occur, the system will temporarily exit “Room
Temperature Mode” and enter “Supply Temperature Mode”.
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Trickle Mode with no enable signal. (Trickle deadband applies)
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Heat Boost Active
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Fan Boost Active
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Purge Mode Active
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3-Speed override by Room Module
7.9 TRICKLE MODE
When trickle mode is active, the fans will run at their minimum speed even
when there is no enable signal. Heating and cooling will also function in this
mode if available. While in trickle mode, the unit will function in “Supply
Temperature Control Mode” but with a different, wider deadband, set by the
network input Trickle Deadband.
7.10 FROST PROTECTION
Should the internal temperature of the unit fall below a value defined in the
commissioning variables, the control will override all heating/cooling logic to
open the LPHW or CW control valves, if fitted. This is to allow any protective
flow through the heating/cooling coils. The supply fan will also stop and the
appropriate frost protection software module will enter an alarm state. This
period will last for a minimum of 5 minutes by default. The fault relay will also
open. Heat and cool demand relays will operate and the software frost alarm
will enter an alarm state.
Please note that frost protection will only function if the Heating Type or
CoolingType setpoints are set to LPHW or CW.
7.11 NIGHT COOLING / SUMMER FREE COOLING
Once enabled in software, this routine uses an individual time schedule to cool
the fabric of the building at night using only the external air. This mode only
functions if the daytime temperature is above the setpoint, cooling is possible
and if the cooling air is not too cold.
7.12 PURGE MODE
Once enabled in software, this routine uses an individual time schedule to
provide a period of increased air change throughout a space. This mode only
functions if the inlet air is above a minimum temperature of 12°C. While purge
is in progress, the unit will function in “Supply Temperature Control Mode” but
with a different, wider deadband, set by the network input “Trickle Deadband”.
7.13 HIBERNATE
This mode is available for LPHW and CW units where the valves are required to
be driven open in anticipation of a period where the unit is electrically isolated
and inactive. When enabled via the network input “Hibernate Mode” this will
stop the fans and open all LPHW & CW valves fully. The unit can then be
powered down. This mode activation is reset upon power cycle so when
restarted the unit will function as normal.
This mode is for periods when to building is left dormant and will stop the coils
trapping water and causing a freeze risk. It will be the buildings responsibility to
provide freeze-preventative heating during this time. This can also be used for a
cleaning or flushing cycle.
7.14 ALARMS
7.14.1 CRITICAL ALARM LATCHING
Once in critical alarm state the unit will drive all heating and cooling outputs to
0V. In the event of fan fail other functions continue as normal. The critical alarm
is latched and required manual reset or power cycle to clear.
Causes of critical alarm:
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Fan fail via fault circuit 1
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Heater overtemp via fault circuit 1
7.14.2 MAINTENANCE ALARMS (NON-LATCHING)
Once in maintenance alarm state the only action taken is de-energising of the
fault relay. Once the trigger is removed, the alarm will reset automatically.
Causes of maintenance alarm:
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Condensate pump fault (This bypasses the heater exchanger automatically)
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Sensor Failure
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Low supply temperature, default 8°C. This can be set to stop fans if required
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Frost protection routine active, default 4°C (This only runs if water valves
are selected as fitted)
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Excessively high supply temperature reading (this will stop heating)
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Filter dP fault (if fitted)
All alarms have a hold off period set by the setpoint “Alarm Delay”.
7.14.3 THERMAL TRIP
In case of software failure, as a final resort, the electric heater is protected by
a fail-safe thermal overload switch. This switch disables the heater controller
once the temperature reaches 80°C. When this occurs, the critical alarm will
latch in software.
Once the unit cools, the contactor will re-engage but the heater signal will
remain at 0V until the critical fault is reset in software or by power cycle.
XBOXER XBC ECOSMART (CO) MODELS
7.0 DESCRIPTION OF CONTROL SOFTWARE STRATEGY
(MS/TP)