Rotex RHYKOMB33AA Installer's Reference Guide

6 Preparation
Installer reference guide
18
RVLQ05+08CAV4 + RHYHBH05AA + RHYHBH/X08AA +
RHYKOMB33AA
ROTEX HPU hybrid
4P355635-1 – 2013.05
Example in case of an underfloor heating application: Maximum
water volume and expansion vessel pre-pressure in case of
55°C
Installation
height
difference
(a)
Water volume
≤280 l >280 l
≤7 m No pre-pressure
adjustment is required.
Do the following:
▪ Decrease the pre-
pressure.
▪ Check if the water
volume does NOT
exceed the maximum
allowed water volume.
>7 m Do the following:
▪ Increase the pre-
pressure.
▪ Check if the water
volume does NOT
exceed the maximum
allowed water volume.
The expansion vessel of
the indoor unit is too
small for the installation.
In this case, it is
recommended to install
an extra vessel outside
the unit.
(a) This is the height difference (m) between the highest point
of the water circuit and the indoor unit. If the indoor unit is
at the highest point of the installation, the installation height
is 0 m.
Example in case of a radiator application: Maximum water
volume and expansion vessel pre-pressure in case of 80°C
Installation
height
difference
(a)
Water volume
≤140 l >140 l
≤7 m No pre-pressure
adjustment is required.
Do the following:
▪ Decrease the pre-
pressure.
▪ Check if the water
volume does NOT
exceed the maximum
allowed water volume.
>7 m Do the following:
▪ Increase the pre-
pressure.
▪ Check if the water
volume does NOT
exceed the maximum
allowed water volume.
The expansion vessel of
the indoor unit is too
small for the installation.
In this case, it is
recommended to install
an extra vessel outside
the unit.
(a) This is the height difference (m) between the highest point
of the water circuit and the indoor unit. If the indoor unit is
at the highest point of the installation, the installation height
is 0 m.
6.3.4 Changing the pre-pressure of the
expansion vessel
NOTICE
Only a licensed installer may adjust the pre-pressure of the
expansion vessel.
When changing the default pre-pressure of the expansion vessel
(1 bar) is required, take following guidelines into account:
▪ Only use dry nitrogen to set the expansion vessel pre-pressure.
▪ Inappropriate setting of the expansion vessel pre-pressure will
lead to malfunction of the system.
Changing the pre-pressure of the expansion vessel should be done
by releasing or increasing nitrogen pressure through the schräder
valve of the expansion vessel.
a
a
Schräder valve
6.3.5 To check the water volume: Examples
Example 1
The indoor unit is installed 5 m below the highest point in the water
circuit. The total water volume in the water circuit is 100 l.
No actions or adjustments are required for either underfloor heating
loops or radiators.
Example 2
The indoor unit is installed at the highest point in the water circuit.
The total water volume in the water circuit is 350 l. Radiators are
installed, so use the graph of 80°C.
Actions:
▪ Because the total water volume (350 l) is more than the default
water volume (140 l), the pre-pressure must be decreased.
▪ The required pre-pressure is:
Pg = (0.3+(H/10)) bar = (0.3+(0/10)) bar=0.3 bar.
▪ The corresponding maximum water volume at 0.3 bar is 205 l.
(See the graph in the chapter above).
▪ Because 350 l is more than 205 l, the expansion vessel is too
small for the installation. Therefore install an extra vessel outside
the installation.
6.4 Preparing electrical wiring
6.4.1 About preparing electrical wiring
WARNING
▪ If the power supply has a missing or wrong N-phase,
equipment will break down.
▪ Establish proper earthing. Do NOT earth the unit to a
utility pipe, surge absorber, or telephone earth.
Incomplete earthing may cause electrical shock.
▪ Install the required fuses or circuit breakers.
▪ Secure the electrical wiring with cable ties so that the
cables do NOT come in contact with the piping or sharp
edges, particularly on the high-pressure side
▪ Do NOT use taped wires, stranded conductor wires,
extension cords, or connections from a star system.
They can cause overheating, electrical shock or fire.
▪ Do NOT install a phase advancing capacitor, because
this unit is equipped with an inverter. A phase
advancing capacitor will reduce performance and may
cause accidents.

Rotex RHYKOMB33AA Specifications

General

Brand	Rotex
Model	RHYKOMB33AA
Category	Boiler
Language	English