77
Monobloc Outdoor Unit Installation Manual
11.2 Steps to clean, purge, and define a flow rate for hydraulic circuit
N°
Without Hydronic Module
With fixed speed hydronic
module
With Variable Speed Hydronic
Module
Adjustable constant speed
With variable speed hydronic
module
T
Cleaning
procedure
1
Open the manual control valve fully (item 17)
No manual control valve required
2
Set the system pump *
3
Read the BPHE pressure drop…
Read the available external static pressure…
4
…by taking the difference of the readings of the pressure gauge connected to the unit inlet and outlet (items 20***)
5
Take another reading
6
Compare this value to the initial value
7
If the pressure drop…
If the available external static pressure…
…has decreased, this indicates that the screen filter must be removed and cleaned, as the hydronic circuit contains solid particles
8
In this case stop the pump* and close the shut-off valves at the water inlet and outlet (items 16) and remove the screen filter (item 19) after emptying the
hydronic section of the unit (items 21 and 22)
9
Repeat, if necessary, to ensure that the filter is not contaminated
Purge
protection
1
After filling with water, wait about 24hrs before activating the purge procedure
2
Activate the purge mode*: water pump is requested to run continuously at maximum speed to purge the hydraulic circuit regardless the flow switch value**
3
The air purge is field-supplied (item 14***)
If the purge is automatic, air will vent from circuit automatically
If the purge is manual, open the valve to vent air from the circuit
11.3 Steps to clean, purge, and define a flow rate for hydraulic circuit
N°
Without Hydronic Module
With fixed speed hydronic
module
With Variable Speed Hydronic Module
Adjustable constant speed
With variable speed hydronic
module
T
Water flow
control
procedure
1
When the circuit is cleaned and purged, activate the pump in quick test mode*, and read the pressures at the
pressure gauges (enteing water pressure – leaving water pressure)…
No need to adjust the flow rate
because of
T
control.
But it is necessary to adjust the
minimum pump speed [P567] to
ensure closure of the switch
2
…to find out the unit pressure drop
(plate heat exchanger and internal
water piping)
3
Compare the value obtained with
the pressure drop (Graph1 below)
Compare the value obtained
with the available external static
pressure (Graph 2 below)
Compare this value to the graph of
available external static pressure using
the appropriate speed curve (Graphs 3 &
4 below)
4
If the pressure read is higher than the value specified the unit flow rate
(and thus system flow) is too high. The pump supplies an excessive
flow rate based on the global pressure drop of the application. In this
case close the control valve and read the new pressure difference
If the flow rate corresponding is higher,
decrease the pump speed*, and vice versa
5
Proceed by successfully closing the control valve until you obtain
the specific pressure that corresponds to the nominal flow rate at the
required unit operating point
Proceed by successfully adjusting the
pump speed until the expected water flow
rate is achieved
1. Pressure drop for unit without hydronic module 17 and 21 kW (heat exc internal piping)
Legend:
1. RUA-CP1701H*
2. RUA-CP2101H*
Data for fresh water at 20°C
Maximum flow rate reduced if
glycol is used in the heating
system
Water flow rate, l/s
Pressure drop, kPa
