Daikin EWAQ016CAW - Changing the Pre-Pressure of the Expansion Vessel; To Check the Water Volume: Examples; Preparing Electrical Wiring; Safety Device Requirements

5 Installation
Installation and operation manual
8
EWAQ016~064CAW + EWYQ016~064CAW
Packaged air-cooled water chiller
4P489435-1B – 2017.10
0
0,5
1
1,5
2
2,5
3
0 50 100 150 200 250 300 350 400 450 500 550 600
A
B
F
C
E
33
b
D
a
a Pre-pressure (bar)
b Maximum water volume (l) (water or water + glycol)
A System without glycol
B System with 30% ethylene glycol
C System with 40% ethylene glycol
D System with 30% propylene glycol
E System with 40% propylene glycol
F Default
If the total water volume in the entire circuit exceeds the maximum
allowed water volume (see graph), an additional expansion vessel
must be installed in the field piping.
The default value of pre-pressure (Pg) is for a height difference of
7m.
If the height difference of the system is lower than 7 m AND the
volume in the system is less than the maximum allowed value at that
pre-pressure (Pg) (see graph), then NO pre-pressure (Pg)
adjustment is required.
4.2.4 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 Schrader
valve of the expansion vessel.
a
a Schrader valve
4.2.5 To check the water volume: Examples
Example 1
The unit is installed 5m below the highest point in the water circuit.
The total water volume in the water circuit is 250l.
No actions or adjustments are required.
Example 2
The unit is installed at the highest point in the water circuit. The total
water volume in the water circuit (no glycol used) is 420l.
Actions:
▪ Because the total water volume (420l) is more than the default
water volume (340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 is approximately 490l
(see graph).
▪ Because 420 l is lower than 490 l, the expansion vessel is
appropriate for the installation.
4.3 Preparing electrical wiring
4.3.1 Safety device requirements
The power supply must be protected with the required safety
devices, i.e. a main switch, a slow blow fuse on each phase and an
earth leakage protector in accordance with the applicable legislation.
Selection and sizing of the wiring should be done in accordance with
the applicable legislation based on the information mentioned in the
table below.
Model Recommended fuses
EWAQ/EWYQ016 25A
EWAQ/EWYQ021 32A
EWAQ/EWYQ025 32A
EWAQ/EWYQ032 40A
EWAQ/EWYQ040 50A
EWAQ/EWYQ050 63A
EWAQ/EWYQ064 80A
NOTICE
When using residual current operated circuit breakers, be
sure to use a high-speed type 300 mA rated residual
operating current.
5 Installation
5.1 Opening the units
5.1.1 To open the outdoor unit
DANGER: RISK OF ELECTROCUTION
DANGER: RISK OF BURNING
To gain access to the unit, front plates need to be opened as follows: