Connection On Heating Side; Electrical Connection - Dimplex LA 8PMS Montage- Und Gebrauchsanweisung

LA 8PMS

6.2 Connection on heating side

The heating system connections on the heat pump have a 1" ex-
ternal thread.
Route the connection hoses out of the device in a downwards di-
rection. Use a spanner to firmly grip the transitions when con-
necting the heat pump. After the heat pump has been installed,
the ductwork must be sealed so that the connection is gastight.
Before connecting the heating water system to the heat pump,
the heating system must be flushed to remove any impurities,
residue from sealants, etc., and to prevent any accumulation of
deposits in the liquifier. A contaminated liquifier may cause the
heat pump to completely break down. For systems in which the
heating water flow can be shut off via the radiator or thermostat
valves, an overflow valve must be installed in a heating bypass
downstream from the heat pump by the customer. This ensures
a minimum heating water flow rate through the heat pump and
helps to avoid faults.
Once the heating system has been installed, it must be filled, de-
aerated and pressure-tested (in the heat pump the air-relief cock
is located at or in the water pipes at the condenser).
Consideration must be given to the following when filling the sys-
tem:
 Untreated filling water and make-up water must be of drink-
ing water quality
(colourless, clear, free from sediments)
Filling water and make-up water must be pre-filtered (pore

size max. 5 µm).
Scale formation in hot water heating systems cannot be com-
pletely avoided, but in systems with flow temperatures below
60 °C the problem can be disregarded.
With medium and high-temperature heat pumps, temperatures
above 60 °C can be reached.
The following standard values should therefore be adhered to
concerning the filling water and make-up water (according to VDI
2035 Sheet 1):
Total alkaline earths
Total heat
in mol/m³ and/or
output in [kW]
mmol/l

up to 200

200 to 600
> 600 < 0.02
Minimum heating water flow rate
The minimum heating water flow rate through the heat pump
must be assured in all operating states of the heating sys-
tem. This can be accomplished, for example, by installing either
a dual differential pressureless manifold or an overflow valve.
The procedure for adjusting an overflow valve is described in the
Chapter Start-Up. When the minimum flow rate is undershot
drastically, the plate steel exchanger in the refrigerating cycle
can freeze, which can lead to total loss of the heat pump.
EN-6
Total
hardness in °dH

2.0 11.2

1.5 8.4
< 0.11
452159.66.35 · FD 9402
NOTE
The use of an overflow valve is only recommended for panel heating and
a max. heating water flow of 1.3 m³/h. System faults may result if this is
not observed.
Antifreeze
Manual drainage should be provided for heat pumps which are
exposed to frost. The antifreeze function of the heat pump man-
ager is active whenever the heat pump manager and the heat cir-
culating pump are ready for operation. If the heat pump is taken
out of service or in the event of a power failure, the system has to
be drained, and if required, blown out, at three locations (see il-
lustration). The heating circuit should be operated with a suitable
antifreeze if heat pump systems are implemented in buildings
where a power failure can not be detected (holiday home).

6.3 Electrical Connection

A standard 3-core cable is used to connect the heat pump to the
power supply.
The power supply and the control line are normally installed in
the ground (in ductwork with a suitable size and resistance) and
routed from the heat pump to the building. This ductwork must
extend into the heat pump by approx. 22 mm and be installed
with a continuous downward slope in order to comply with Sec-
tion 42 of the VDE 0100 regulations. Instead of 90° bends, two
45° bends must be used as pipe bends. The control line and the
cable for the power supply are drawn into this ductwork.
The cable (power supply) must be provided by the customer. The
conductor cross section is selected in accordance with the power
consumption of the heat pump (see Appendix Device Informa-
tion) and the applicable VDE (EN) and VNB regulations.
The power supply line on the heat pump must be fed through the
provided cable feedthrough into the switch box. The line must be
firmly screwed to its feedthrough (vapour sealed pipe union).
An all-pole disconnecting device with a contact gap of at least 3
mm (e.g. a utility blocking contactor or power contactor) and a 1-
pole circuit breaker (tripping current in compliance with the de-
vice information) must be installed in the power supply for the
heat pump.
The control voltage is supplied via the heat pump manager.
The heat pump manager has a 230 V AC-50 Hz power supply.
Connect the controller in compliance with its own operating in-
structions (16 A fuse).
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