EAS ELECTRIC ETHKH160 Manual De Instrucciones página 70

■ Because brass is a soft material, use
appropriate tooling for onnecting the
water circuit.
Inappropriate tooling will cause damage
to the pipes.
The unit is only to be used in a closed water system. Application in
an open water circuit can lead to excessive corrosion of the water
piping:
■ Never use Zn-coated parts in the water circuit. Excessive
corrosion of these parts may occur as copper piping is used in
the unit's internal water circuit.
■ When using a 3-way valve in the water circuit.Preferably choose
a ball type 3-way valve to guarantee full separation between
domestic hot water and floor heating water circuit.
■ When using a 3-way valve or a 2-way valve in the water circuit.
The recommended maximum changeover time of the valve
should be less than 60 seconds.
Protecting the water circuit against freezing
Frost can cause damage to the hydraulic system. As this unit is
installed outdoors and thus the hydraulic system is exposed to
freezing temperatures, care must be taken to prevent freezing of the
system.
All hydraulic parts are insulated to reduce heat loss. Insulation must
be foreseen on the field piping.
The unit is already equipped with several features to prevent
freezing.
■ The software contains special functions using heat pump to
protect the complete system against freezing.
when the temperature of the water flow in the system drop to a
certain value, the software will take action to heat the water,either
by the heat pump or the electric heating tap, or backup heater.
The freeze protection function will turn off only when the
temperature increase to a certain value.
However in case of power failure, above mentioned features can not
protect the unit from freezing.
If power failure can happen at times the unit is unattended, the
supplier recommends adding glycol to the water system. Refer to
Caution: "Use of glycol".
Depending on the expected lowest outdoor temperature, make sure
the water system is filled with a weight concentration
of glycol as mentioned in the table below.
When glycol added to the system, the performance of the unit will be
affected, the correction factor of the unit capacity、flow rate and
pressure drop of the system listed in the table below：
Freezing point(℃)
0 -5
Percentage of ethylene glycol in weight
0 12%
cPf 1 0.98
cQ 1 1.02
cdp 1 1.07
cPf: correction factor for unit heating capacity
cQ: correction factor for flow rate
cdp: correction factor for system pressure drop
If no glycol added to the system，water must be drain out when
power supply failure.
Besides,water may enter into the flow switch, which can't be drain
out and may freezing when the temperature is low enough, so you
should remove the flow switch and dry it, then you can install it into
the unit.
NOTE
-10 -15 -20
20% 28% 35%
0.97 0.965 0.96
1.04 1.075 1.11
1.11 1.18 1.22
■ Counterclockwise rotation, remove the flow switch.
■ Drying the flow switch completly.
(a) ETHYLENE GLYCOL IS TOXIC
The concentrations mentioned in the table above will not prevent
the medium from freezing, but prevent the hydraulics from
bursting.
Use of glycol
■ Use of glycol for installations with a domestic hot water tank:
- Only propylene glycol having a toxicity rating or class of 1, as
listed in "Clinical Toxicology of Commercial Products, 5th
edition" may be used.
The maximum allowed water volume is then reduced according to
the figure "Maximum allowed water volume" Refer to the
Installation.
■ In case of over-pressure when using glycol, be sure to connect the
safety valve to a drain pan in order to recover the glycol.
Corrosion of the system due to presence of glycol
Uninhibited glycol will turn acidic under the influence of oxygen. This
process is accelerated by presence of copper and at higher
temperatures. The acidic uninhibited glycol attacks metal surfaces
and forms galvanic corrosion cells that cause severe damage to the
system.
It is therefore of extreme importance:
-25
■ That the water treatment is correctly executed by a qualified water
40%
specialist;
0.955
1.14
■ That a glycol with corrosion inhibitors is selected to counteract
1.24
acids formed by the oxidation of glycols;
■ That in case of an installation with a domestic hot water tank, only
the use of propylene glycol is allowed. In other installations the
use of ethylene glycol is permitted as well;
■ That no automotive glycol is used because their corrosion
inhibitors have a limited lifetime and contain silicates
foul or plug the system;
■ That galvanized pipingis not used in glycol systems since its
presence may lead to the precipitation of certain components in
the glycol's corrosion inhibitor;
■ That it has to be made sure the glycol is compatible with the used
materials in the system.
18
1
2
There need drying
NOTE
WARNING
CAUTION
V.1
which can