19
ATTENTION: Once the motor pulley opening or closing
has been set, check that the setscrews have been correctly
tightened.
ELECTRICAL CONNECTIONS
WARNING: To prevent electrical shock or equipment
damage, make sure disconnects are open before electrical
connections are made. If this action is not taken, personal
injury may occur.
NOTE: The power supply for the units has to be in accor-
dance with applicable standards and laws, the low voltage
directive, etc.
•
Connect the power supply for the complete system
(outdoor unit and indoor unit) via the 38UQZ outdoor
unit (see Fig. 3).
•
Consult the wiring diagram supplied with the unit, that
shows all power connections between the 38UQZ out-
door unit and the 40ALZ indoor unit and the general
power supply to the system.
•
The connection cables between the units must not be
lighter than the flexible Neoprene-covered cable (type
H0 RN-F), with an appropriate wire section for the
supply to the 40ALZ unit.
•
The power of the optional electric heater of the indoor
unit is supplied via the main disconnect switch of the
38UQZ unit (see Fig. 1).
Fig. 23 - general unit power supply
Legend
Q1: Main unit power supply disconnect switch.
Located in the outer panel of the 38UQZ unit.
F1: Field-installed fuses.
• Route all cables through the conduits in the 38UQZ
units to the terminals of the main disconnect switch
(see unit wiring diagram).
• Voltage to the unit must be within 10% of the nominal
given in the electrical data table with a maximum phase
imbalance of %. Contact your local power company
for correction of an incorrect line voltage.
• Take special care when making the earth connection.
This is the first cable to be connected, and it must be
longer than the live cables.
•
Operation of the unit on improper line voltage consti-
tutes abuse and is not covered by the Carrier warranty.
IMPORTANT: To ensure the correct unit power supply it
is necessary first to determine the wire section. The unit
electrical data (see Table 2 - Electrical Data) and the line
length (max. admissible voltage loss 5%) must be taken
into consideration.
If the indoor unit includes an electric heater, this must be
taken into consideration when sizing the system power
supply cable (38UQZ-40ALZ) and the isolator switch
and fuses.
• Never operate a unit if the voltage imbalance exceeds
10%. The following formula must be used to determine
the percentage of voltage imbalance.
Voltage imbalance % =
Largest deviation from average voltage
Average voltage
example:
Nominal supply: 400-3-0
AB = 404 V
BC = 399 V
AC = 394 V
Average voltage = 404 + 399 + 394 = 399 = 400 V
3
Determine maximum deviation from average voltage:
AB = 404 - 400 = 4
BC = 400 - 399 = 1
AC = 400 - 394 = 6
Largest deviation is 6 volts. Percentage voltage imbalance
is therefore:
6
x 100 = 1. %
400
•
The cables marked
1
from the 40ALZ indoor units
are run to the 38UQZ outdoor unit control box for
connection to the fan motor, and in the case of the
optional electric heater also cables marked
2
.
