SYSHRW Engineering Data Manual (EDM HRW S 4GB)
µBMS mini-supervision station
SYSHRW
4
Control Features (continued)
Variable sequential start-up function : when the system is rst
energised, or after a power cut, or after opening and closing the "CLK"
contact, a random time delay of 0 to 30 seconds is introduced by the
electronic board to prevent the water source heat pumps from all
starting up simultaneously, thus avoiding a power surge.
Emergency shut-down / stand-by / night setback : the electronic
board has two "CLK" terminals which shut the unit down immediately.
By incorporating an area thermostat in series, the "CLK" contact can
also be used as a night setback and the water source heat pump will
start up again as soon as the ambient temperature drops below the
set point of the setback thermostat.
Anti-freeze safety function : this is provided by two temperature
sensors. In cooling mode an "ICT" temperature sensor located in the
nned coil protects the water source heat pump against accidental
freezing.
In heating mode, the safety function is provided by an "LWT" minimum
water outlet temperature sensor.
A minimum water ow in the unit is ensured by a differential pressure
switch.
The automatic reset LP pressure switch completes the anti-freeze
safety function by monitoring a minimum acceptable suction pressure
to ensure correct operation of the compressor.
High temperature safety function : the "ICT & LWT" temperature
sensors check that the condensation temperature at the nned coil
and the water temperature at the outlet of the water/refrigerant heat
exchanger do not exceed the authorised limits.
The manual reset HP pressure switch completes the high temperature
safety function.
Condensate drain pan uid level safety function : the STORM 2
electronic board permanently monitors the water level in the
condensate drain pan, by means of a oat type contact switch.
If the water reaches an abnormally high level, the machine is switched
to safety mode.
The STORM 2 electronic board also enables the general machine fault
to be sent to a remote fault relay via a dry contact (optional).Phase
monitor : The water source heat pumps (three-phased models) are
factory equipped with a phase monitor to detect the presence and
order of the phases.
Motorized valve : The STORM 2 electronic board has a 230 volt output
for an (optional) motorized valve controlled by the operation of the
compressor, in order to enable the ow-rate of the hydraulic pump(s)
to be regulated according to the manometric pressure in the water
source.
System without water source heater : The STORM 2 electronic board
can be congured to stop the water source heat pump if the water
temperature in the system becomes too low, and to automatically start
an electric air ow heater which is monitored by the room temperature
regulation sensor (RCX) or the air intake temperature sensor (RAT).
Electric heater : SYSHRW water source heat pumps can be factory
equipped with an optional in-duct air heater located at the fan outlet.
The electric heaters are also available in kit.
The electric heater function can, depending on the conguration of
the STORM 2 electronic board, be used in place of the thermodynamic
heating as soon as the temperature in the water system drops below
a minimum limit, or it can be used as an electric heating system on
its own.
The SYSHRW size 019, which operate on a single-phase 230 volt
mains supply, is factory equipped with two electric heater stages. The
other models, which operate on a three-phase 400 volt mains supply,
have a single-stage electric heater.
µBMS mini-supervision station
This centralised control unit is proposed as an option, and can be
installed in place of the local RCX remote control or connected to the
STORM 2 electronic board as a supervision station to monitor and
manage 32 water source heat pumps in 15 zones from a single point,
in addition to the local RCX remote controls.
The µBMS mini-supervision station enables the zones to be
programmed with global control for all zones, or with individual control
of each zone with programming of the operating time ranges over
a 7 day period, with management of the heating, cooling and night
setback modes.
It also provides the possibility of having different set-points in different
zones.
MODBUS interface
The ModBus interface for communication with a BMS, is available as
optional in the STORM 2 electronic board.