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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 flow 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 flow.
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 flexible
connections at the chiller piping in order to reduce the
transmission of vibrations.
5.4 - FILTERS
ATTENTION
It is advisable to use mesh filters 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. Carrier 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.
64
Voltage imbalance calculation:
- Voltage imbalance (%)=
= Max. deviation of the average voltage x 100
Voltage average
- Exemple:
380V - 3 phase - 60Hz
- Measurement: AB = 383V
383 + 378 + 374
- Voltage average =
- 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%
(OK)
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 flow 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 flow cold water. The indicative arrow marked in
the lateral of the water flow will have to be pointed in the
direction to the flare in the exit nipple.
To great details it goes until the electrical diagram and verifies
the interconnection of the key flow with the equipment.
BC = 378V
AC = 374V
= 378 V
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