Water Pipework - Mitsubishi Electric ecodan EHPT20Q-VM2EA Installation Manual

4
Installation

4.3 Water Pipework

Hot Water Pipework
The cylinder unit is UNVENTED.
(Scotland) and P5 (Northern Ireland) should be adhered to. If outside of the
UK please adhere to your own country' s regulations for unvented hot water
systems.
system should be
checked on installation for any abnormalities;
Primary circuit)
Primary expansion vessel pre-charge
from Safety devices should be followed carefully.
as dirt or
debris enter the pipe.
Cold Water Pipework
Cold water to the suitable standard (see section 4.2) should be introduced to
the system by connecting pipe B (Figure 3.1) using appropriate fittings.
Negative pressure prevention
negative pressure effecting water installer should install
pipework or use appropriate devices.
Hydraulic filter work
Install a hydraulic filter or strainer (local supply) at the water intake ("Pipe E" in
Fig.3.1)
Pipework Connections
Connections to the cylinder unit should be made using the 22 mm compression
as appropriate.
Do not over-tighten compression fittings as this will lead to deformation of the
olivering and potential leaks.
Note: To weld the pipes in the field, ensure the pipes on the cylinder unit are
cooled using wet towel etc.
Insulation of Pipework
pipework and connections at the top of the cylinder unit should be carefully
insulated.
to avoid unwanted heat transfer.
m K.
Sizing Primary Expansion Vessels
Primary expansion vessel volume fit the local system water volume.
graph can be used.
× G
V =
P ¹ + 0.098
P ² + 0.098
V : Necessary expansion vessel volume [L]
G
P : Expansion vessel setting pressure [MPa]
1
P : Max pressure during operation [MPa]
2
Graph to the right is for the following values
: at 70 °C = 0.0229
P : 0.1 MPa
1
P : 0.3 MPa
2
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Filling the System (Primary Circuit)
Note: Make sure to turn OFF the booster heater power supply before filling the
system
1. Check all connections including factory fitted ones are tight.
2. Insulate pipework between cylinder unit and outdoor unit.
4
tion.)
5.
Always use a new filling loop with double check valve when filling the
primary circuit to avoid back flow contamination of water supply.
Do not use an old filling loop.
Do Not turn ON the system until the system is fully charged of water.
section) .
section 4.2 for instruction). Corrosion inhibitor should be used in both split
model and packaged model systems.
prevent a corrosive reaction taking place which will damage the pipework.
6
tions.
7. Pressurise system to 1 bar with all the water in thermal store tank cold.
inclusion in pump may be caused by the pressure drop of the system that
occurs if the hot water gets cold. )
8. Release all trapped air using air vents during and following heating period.
9
Note: be installed at the highest point of the primary
even cause the cylinder unit to fault.
Confirm the following if the air cannot be discharged.
radiators
valves
IMPORTANT<Air discharging of pump A>
accessory rubber hose to the
water from dripping on to the pump during
the air bleeding operation.
and discharge the air.
tap and confirm that hot water is
supplied after approximately 30 minutes from
the beginning of thermal store operation.
Note: If the air is not sufficiently discharged, hot water is not supplied and an
error occurs. Continue to discharge the air until smooth delivery of hot
-
water.
Primary expansion vessel sizing
25
20
15
10
5
0
0 50 100 150 200 250 300
System water volume [L]
<Figure 4.3.1>
4
Installation
Flow rate setting
Circulation flow rate of EHPT20Q-VM2EA unit is determined by settings of "Flow
rate setting" and "pump speed".
1. Primary circuit for thermal store and space heating
In the space heating operation,circulation flow rate can be selected by main
controller setting.(refer to page 29) Pump 1 automatically operates to adjust the
flow rate to the setting. Auto setting automatically selects a flow rate appropriate
for effective operation.
In the thermal store operation, circulation flow rate is automatically selected to
-
adjust the hot water temperature to the main remote controller setting and pump 1
automatically operates.
In other operations (ex. Freeze stat operation,Emergency mode,Indoor unit only
operation), pump 1 operates at a pump speed selected by main controller setting.
(See Figure 4.3.2)
Adjust the pump speed setting so that the flow rate in the primary circuit is appro-
priate for the outdoor unit installed.(see Table 4.3.1)
Water circulation pump 1 characteristics
160.0
140.0
120.0
100.0
- 80.0
60.0
40.0
20.0
Pump Speed 1
0.0
0 2
<Figure 4.3.2>
*The performance showing Figure 4.3.2 includes pressure drop of both cylinder unit and outdoor unit.
Before installation, please check if the maximum performance of water circulation pump 1 can accommodate the pressure drop of external heating circuit.
Safety Device Connections
The primary pressure relief valves on the primary side needs appropriate
discharge pipework.
Note: Do not secure the screws excessively when connecting the
Manual
Discharge pipe, otherwise this may result in damage to the cylinder
air vent
unit.
Pressure relief valve connections should not be used for any other
purpose.
*1 In accordance with Building Regulations a tundish MUST be fitted into the pipe-
work within 500 mm of the safety device. Due to the distance between the two
safety devices it may be necessary to fit each safety device with its own tundish
before you run the pipework together to a safe discharge.(See Figure 4.3.3)
Diagram Description
part No.
10 Pressure relief valve
<Table 4.3.2>
Always refer to local regulations when installing discharge pipework.
Install discharge pipework in a frost-free environment.
It is necessary to provide appropriate drainage from the pressure relief valve
situated on top of the cylinder unit to prevent damage to the unit and the
surrounding area from any steam or hot water released. Relief valves MUST
NOT be used for any other purpose.
350 400
Outdoor unit
QUHZ-W40VA
* If the water flow rate exceeds 9.0L/min, the flow speed will be greater than
1.5m/s, which could erode the pipes.
* In case of "Compensation curve mode" or "Flow temp. mode" please select
"Manual" mode then choose flow rate manually from 3.0 to 8.0 L/min. If "Auto"
mode is selected, flow rate will be fixed at "7.0 L/min".
2. Primary circuit for hot water supply
Pump A automatically operates regardless of the flow rate the settings.
Pump Speed 5(Max)
Pump Speed 4
Pump Speed 3
Pump Speed 2
4 6 8 10
Tundish
Connection Connection
size type
G 1/2 Female
Water flow rate range [L/min]
3.0 - 8.0
<Table 4.3.1>
10
DHW
Cold water inlet
10
HEX
<Figure 4.3.3>
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