28
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.
The unit power supply cables must not be lighter than normal
flexible polychloroprene covering cable (designation H05 RN-F).
Route all cables through the conduits incorporated in the unit
(50VZ/PZ or 38VZ/PZ) to the main disconnect switch terminals
(see wiring diagram).
Voltage to the unit must be within 2% of the voltage and 10%
of the current indicated on the nameplate. Contact your local
power company for correction of an incorrect line voltage.
Take special care when making the earth connection. This
cable must be connected first and it must be longer than
the power cable.
WARNING: Operation of the unit on improper line voltage
constitutes abuse and is not covered by the Carrier warranty.
IMPORTANT: To ensure the correct power supply, it is necessary
to first determine the cable section. This must take into account
the unit electrical data (see electrical data table) and the line
length (max. permissible voltage drop 5%).
If the unit includes electric heat, this must be taken into account
for the supply line sizing.
Never operate a unit if the voltage imbalance exceeds 2%. The
following formula must be used to determine the percentage of
voltage imbalance.
Voltage imbalance % =
Largest deviation from average voltage
Average voltage
Fig. 21 - Horizontal drain (40PZ)
Field-supplied
Drain pipe OD 25 mm
Drain pan
Unit base
Example:
Nominal supply: 400-3-50
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 = 1.5%
400
VERY MPORTANT: The installer must protect the unit power
supply line with automatic disconnect devices, a thermal-
magnetic switch and a differential disconnect switch, suitable
for the installation and in according with applicable legislation.
Electrical connection between the units (38VZ/PZ and
40PZ)
The general power supply for the complete system (indoor and
outdoor unit) must be made via the outdoor unit (38VZ/PZ).
Consult the wiring diagram that is supplied with the units. This
will show all power connections to be made between the 38VZ/
PZ unit and the 40PZ unit.
The unit connection cables must not be lighter than normal
flexible polychloroprene covering cable (designation H05 RN-F)
with a wire section that is adequate for the 40PZ unit power
consumption.
The power supply for the electric heater of the indoor unit must
be provided from the main disconnect switch.
Thermostat connection
Thermostat/unit connection must be via a loom (wire section
1 mm
2
) manufactured in accordance with the wiring diagram
accompanying the unit.
Follow the instructions supplied with the control for thermostat
assembly and handling.
The general rules below should be taken into account:
