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4.8. Electrical Connections
a) Power supply
Install close the unit a fused disconnect switch or
thermomagnetic circuit breaker with equivalent breaking
characteristics in accordance with the local requirements. The
electrical data are indicated in the Electrical Data section.
Consult an electrician or technician accredited by CREA
(Regional Council of Engineering and Architecture) to evaluate
the conditions of the electrical system in the facilities, and
select the appropriate power and protection devices.
Carrier is not responsible for any problems resulting from
failure to comply with this recommendation.
It is advisable to use a padlock to lock the switch or circuit
breaker open while servicing the equipment.
b) Power wiring
There are openings to pass in the wiring on both sides of the
liquid chiller units. Install wiring from the customer’s point of
strength directly in the switchboards of each chiller unit.
Make sure to install a ground conductor. The voltage supplied
should be according to the voltage on the reference board.
The voltage between the phases must be balanced within 2%
unbalance and the current within 10%, with the compressor
running. Contact your local power supply company for
improper voltage correction or phase unbalance.
4.9. Application Data
Unit operating range
Minimum water fl ow
If the installation flow rate is below the minimum flow,
recirculation of water flow may occur in the evaporator with
risk of excessive fouling.
Unit
30EV_15
30EX_15
Minimum fl ow on evaporator
m
3
/h
4,2
4,4
Maximum fl ow on evaporator
m
3
/h
15,3
18,2
Maximum outdoor temperature
°C
45
45
Minimum outdoor temperature
°C
10
10
Maximum REWT (evaporator)¹
°C
35
35
Minimum REWT (evaporator)¹
°C
6
6
Maximum ULWT (evaporator)²
°C
35
35
Minimum ULWT (evaporator)²
°C
5
5
Minimum temperature delta
°C
3
3
Maximum temperature delta
°C
10
10
Notes:
- For continuous operation, the maximum temperature delta
(REWT-ULWT) should not exceed 10 ° C.
1 For continuous operation, REWT must be within the range of
8.0 ° C to 20.0 ° C.
2 The standard control set point is 5 ° to 14 ° C. This value may
vary depending on the FLWD of the project and the unit
number confi gured in the control. In continuous operation
at full load the maximum ULWT shall not exceed 15.0 ° C.
See Attachment III “Table Set Point”.
Notes:
- The calculation of the current unbalance must be done in
the same way as the voltage unbalance.
- The causes of voltage unbalance can be:
* Bad contact (in meter contacts, electrical connections,
loose wire, rusty or charred lead wire)
* Wrong diameter lead wires
* Load unbalance in a three-phase power system
.
c) Field components interconnection
Refer to the electrical diagram to make the fi eld
interconnections between fi eld components and liquid
chiller units.
Voltage unbalance calculation
- Voltage unbalance (%) = Larger diff erence from average
voltage / Average voltage:
- Example: Rated power supply
380 V - 3 phases - 60 Hz
- Measurements:
AB = 383 V
BC = 378 V
AC = 374 V
- Average Voltage =
383 + 378 + 374 = 378 V
3
- Diff erence from average voltage:
AB = 383 - 378 = 5
BC = 378 - 378 = 0
AC = 378 - 374 = 4
- Grater difference is AB = 5 therefore, % voltage
unbalance is:
5 x 100 = 1,32 %
(OK - allowed unbalancing)
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