Daikin EWAD-C User Manual

D–EIMAC01603-18_02EN - 18/27
Table 1 - Acceptable water quality limits
DAE Water quality requirements
Shell&tube +
Flooded
BPHE
Ph (25 °C)
6.8 ÷ 8.4
7.5 – 9.0
Electrical conductivity [μS/cm]
(25°C)
< 800
< 500
Chloride ion [mg Cl
-
/ l]
< 150
< 70 (HP
1
);
< 300 (CO
2
)
Sulphate ion [mg SO
4
2-
/ l]
< 100
< 100
Alkalinity [mg CaCO
3
/ l]
< 100
< 200
Total Hardness [mg CaCO
3
/ l]
< 200
75 ÷ 150
Iron [mg Fe / l]
< 1
< 0.2
Ammonium ion [mg NH
4+
/ l]
< 1
< 0.5
Silica [mg SiO
2
/ l]
< 50
-
Chlorine molecular (mg Cl
2
/l)
< 5
< 0.5
Note: 1. Heat Pump
2. Cooling Only
5.11 Evaporator and recovery exchangers anti-freeze protection
All evaporators are supplied with a thermostatically controlled anti-freeze electrical resistance, which provides adequate
anti-freeze protection at temperatures as low as –16°C. However, unless the heat exchangers are completely empty and
cleaned with anti-freeze solution, additional methods should also be used against freezing.
Two or more of below protection methods should be considered when designing the system as a whole:
• Continuous water flow circulation inside piping and exchangers
• Addition of an appropriate amount of glycol inside the water circuit
• Additional heat insulation and heating of exposed piping
• Emptying and cleaning of the heat exchanger during the winter season
It is the responsibility of the installer and/or of local maintenance personnel to ensure that described anti-freeze methods
are used. Make sure that appropriate anti-freeze protection is maintained at all times. Failing to follow the instructions
above could result in unit damage. Damage caused by freezing is not covered by the warranty.
5.12 Installing the flow switch
To ensure sufficient water flow through the evaporator, it is essential that a flow switch be installed on the water circuit.
The flow switch can be installed either on the inlet or outlet water piping. The purpose of the flow switch is to stop the unit
in the event of interrupted water flow, thus protecting the evaporator from freezing.
The manufacturer offers, as optional, a flow switch that has been selected for this purpose.
This paddle-type flow switch is suitable for heavy-duty outdoor applications (IP67) and pipe diameters in the range of 1” to
6”.
The flow switch is provided with a clean contact which must be electrically connected to terminals shown in the wiring
diagram.
Flow switch has to be tune to intervene when the evaporator water flow is lower than 50% of nomila flow rate.
5.13 Heat recovery
Units may be optionally equipped with heat recovery system.
This system in made by a water cooled heat exchanger located on the compressors discharge pipe and a dedicated
managment of condensing pressure.
To gurantee compressor operation within its envelope, units with heat recovery cannot operate with water temperature of
the heat recovery water lower than 28°C.
It is a responsability of plant designer and chiller installer to grantee the respect of this value (e.g. using recirculating bypass
valve)

Daikin EWAD-C Specifications

General

Brand	Daikin
Model	EWAD-C
Category	Chiller
Language	English