Table of Contents
Advertisement
6.2 - 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.
Field wiring must comply with all applicable codes.
Take special care when making the earth connection.
(Caution: Not all cables marked GND are earth cables.)
Voltage to the unit must be within 10% of the voltage and 10%
of the current indicated on the nameplate. Contact your local
power company for correction of an incorrect line voltage.
Check the voltage before selecting supply wiring fuses and
controls.
WARNING: Operation of the unit on improper line voltage
constitutes abuse and is not covered by the Carrier warranty.
IMPORTANT: To ensure the correct unit power supply
(cable entry, conductor cross section, protection devices etc.),
consult the electrical data table, the wiring diagram supplied
with the unit and the applicable standards concerning the
installation of air conditioning equipment.
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
Example: Nominal supply: 400-3-50
AB = 404 V
BC = 399 V
AC = 394 V
Average voltage =
404 + 399 + 394
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
CAUTION: The installer must install protection devices, as
required by the applicable legislation.
18
Motor
= 399 = 400 V
3
6.2.1 - Inserting line power leads into the unit
Install airtight cable conduit connectors through the knockouts
provided. Route all cables across the connectors to the terminal
blocks in the control box.
Use copper cables for the power supply into the unit.
6.3 - Liquid refrigerant charge
6.3.1 - Checking the charge
WARNING: When adjusting the refrigerant charge always
ensure that water is circulating in the condenser and
evaporator to prevent any possibility of freezing up. Damage
caused by freezing is not covered by the product warranty.
30SZ units are shipped with a sufficient charge of refrigerant.
Refer to the Physical Data table. If it is nevertheless necessary
to add more refrigerant, run the unit at full capacity for some
time and then add refrigerant until there are no bubbles in the
sight glass. This will generally mean adding more refrigerant
than would be needed to prevent bubbles from being seen in
the sight glass.
30SZV condenserless units are shipped with only a nitrogen
charge, leaving the whole system to be charged after the
installation is complete. To adjust the charge continue adding
liquid refrigerant, with the unit running at full capacity until
there are no bubbles visible in the sight glass.
WARNING: To ensure proper operation of 30SZ units there
must be at least 5 K of subcooling as the liquid refrigerant
enters the expansion valve.
30SZ and 30SZV units use a HFC-407C refrigerant charge.
For your information, we are reproducing here some extracts
from the official publication dealing with the design, installa-
tion, operation and maintenance of air conditioning and
refrigeration systems and the training of people involved in
these activities, agreed by the air conditioning and refrigeration
industry.
Advertisement
Table of Contents
