Cold Water Piping/Connections; Filters; Electric Connections - SURREY CWAZH072 Manual De Instalación, Operación Y Mantenimiento

5.3 - COLD WATER PIPING/CONNECTIONS

Develop a piping design in a way it has minimum changes
of the elevation levels. Install manual or automatic air purge
valves at the highest points of the line, keeping the system
pressure through a pressurization tank with relief and
reducing valves. Install thermometers and pressure gauges
at the water outlet and inlet lines of the unit.
Install measurement points of the fl ow at the cold water
piping. To adjust as table, characteristics techniques, the
loss of nominal load of the evaporator.
It is recommended to use a globe valve to set the water
fl ow. Put draining connections at all the low points of the
hydraulic installation in order to allow a full draining of the
system. Install blocking valves near the water inlet and
outlet connections. To clean the lines before the operating
units use fl exible connections at the chiller piping in order
to reduce the transmission of vibrations.

5.4 - FILTERS

ATTENTION
It is advisable to use mesh fi lters installed in the
evaporator inlet liquid line (Plate Exchanger), the
nearest possible to the inlet piping.

5.5 - ELECTRIC CONNECTIONS

a) GENERAL POWER SUPPLY:
Install near the unit a switch isolator with fuses or a
thermo-magnetic circuit breaker with equivalent rupture
characteristics. The technical data of the unit are indicated
on table 5.6.
Consult an electric engineer or an accredited technician
to evaluate the electric system conditions and the proper
protection. Surrey is not liable for problems caused by the
non-observance of this recommendation.
It is recommended to use a lock to block the switch or any
open circuit breaker during the maintenance of the unit.
b) POWER CABLING:
Install the connection from the power input point of the
customer directly to the terminal of the unit.
The power supply cables should bear the sum of the
maximum currents. Do not forget to install the protective
cable (grounding). The voltage shall be in accordance to
the voltage of the nameplate.
The section of the feeder from the unit must more be
dimensioned for addition of maximum chains, or either, equal
the 125% of compressor or motor greater 100% of all the
other compressors and engines. The handles will have to
be classe 90°C or superior.
The voltage between the phases shall be balanced within
the 2% of imbalance and the current within 10%, with the
compressor in operation. Contact your local power supplier
in order to correct any improper voltage or the phase
imbalance.
32
Voltage imbalance calculation:
- Voltage imbalance (%)=
= Max. deviation of the average voltage x 100
Voltage average
- Exemple:
- Voltage average = 383 + 378 + 374
- Maximum deviation of the voltage average:
AB = 383V - 378V = 5V
BC = 378V - 378V = 0V
AC = 378V - 374V = 4V
- Highest difference is 5V. Then, the voltage imbalance in % is:
5 x 100 = 1,32%
378
Notes:
- The following items can cause voltage imbalance:
• Bad contact (in contact with contactors, electric
connections, loose cables, oxidized or burnt conductors);
• Improper conductor sections;
• Load unbalancing in 3-phase power supply system.
- The current imbalance calculation shall be made in the
same way as the voltage imbalance calculation.
c) COLD WATER FLOW SWITCH (CWFS)
On each unit there must be a cold water flow switch in
order to protect the equipment against low water flow
(Not provided/installer responsibility).
IMPORTANT
If a water fl ow switch is not installed, the equipment
warranty will be void.
The installation must be made in the water outlet
installation.
ATENÇÃO
It is necessary to have care in the installation of
the key of the fl ow cold water. The indicative arrow
marked in the lateral of the water fl ow will have to be
pointed in the direction to the fl are in the exit nipple.
To great details it goes until the electrical diagram
and verifies the interconnection of the key flow with
the equipment.
380V - 3 - phase - 50Hz
- Measurement: AB = 383V
BC = 378V
AC = 374V
= 378 V
3
(OK)