Electrical Connection; Power Supply; Voltage Phase Imbalance (%); Recommended Wire Sections - Carrier AquaSnap 61AF 022 Installation, Operation And Maintenance Instructions

7 - ELECTRICAL CONNECTION

Please refer to the certified dimensional drawings, supplied with
the unit (also available on the internet).

7.1 - Power supply

The power supply must conform to the specification on the unit
nameplate. The supply voltage must be within the range specified
in the electrical data table. For connections refer to the wiring
diagrams and the certified dimensional drawings.
WARNING: Operation of the unit with an improper supply
voltage or excessive phase imbalance constitutes abuse
which will invalidate the Carrier warranty. If the phase
imbalance exceeds 2% for voltage, or 10% for current, contact
your local electricity supply at once and ensure that the heat
pump is not switched on until corrective measures have been
taken.

7.2 - Voltage phase imbalance (%)

100 x max. deviation from average voltage
Average voltage
Example:
On a 400 V - 3 ph - 50 Hz supply, the individual phase voltages
were measured to be:
AB = 406 V; BC = 399 V; AC = 394 V
Average voltage = (406 + 399 + 394)/3 = 1199/3
= 399,7 say 400 V
Calculate the maximum deviation from the 400 V average:
(AB) = 406 - 400 = 6
(BC) = 400 - 399 = 1
(CA) = 400 - 394 = 6
The maximum deviation from the average is 6 V. The greatest
percentage deviation is: 100 x 6/400 = 1.5%
This is less than the permissible 2% and is therefore acceptable.

7.3 - Recommended wire sections

Wire sizing is the responsibility of the installer, and depends on
the characteristics and regulations applicable to each installation
site. The following is only to be used as a guideline, and does
not make Carrier in any way liable. After wire sizing has been
completed, using the certified dimensional drawing, the installer
must ensure easy connection and define any modifications
necessary on site.
The connections provided as standard for the field-supplied power
entry cables to the general disconnect/isolator switch are designed
for the number and type of wires, listed in the table below.
The calculations are based on the maximum machine current (see
electrical data tables). Standard installation practises for units
installed outside have been applied in accordance with IEC 60364,
table 52C:
- No. 17: suspended aerial lines,
- -No. 61: buried conduit with a derating coefficient of 20.
Motor
The calculation is based on PVC or XLPE insulated cables with
copper core. A maximum ambient temperature of 40°C has been
taken into consideration for 61AF units. The given wire length
limits the voltage drop to < 5%..
IMPORTANT: Before connection of the main power cables (L1
- L2 - L3) on the terminal block, it is imperative to check the
correct order of the 3 phases before proceeding to the
connection on the main disconnect/isolator switch.
7.3.1 - Power cable entry
The power cables can enter the 61AF control box from below or
from the side of the unit, at the bottom of the angle iron.
Prepunched holes facilitate the entry. Refer to the certified
dimensional drawing for the unit. An opening below the control
box allows introduction of the cables.

7.4 - Field control wiring

Important: Field connection of interface circuits may lead to
safety risks: any control box modification must maintain
equipment conformity with local regulations. Precautions
must be taken to prevent accidental electrical contact between
circuits supplied by different sources:
- The routing selection and/or conductor insulation
characteristics must ensure dual electric insulation.
- In case of accidental disconnection, conductor fixing
between different conductors and/or in the control box
prevents any contact between the conductor ends and
an active energised part.
Refer to the 61AF SmartVu
diagram supplied with the unit for the field control wiring of the
following features:
- Condenser pump interlock (mandatory)
- Remote on/off switch
- Demand limit external switch
- Remote dual setpoint switch
- Alarm, alert and operation report
7.5 - Power supply
After the unit has been commissioned, the power supply must
only be disconnected for quick maintenance operations (one day
maximum). For longer maintenance operations or when the unit
is taken out of service and stored the power supply must be
maintained to ensure supply to the heaters (unit frost protection).

7.6 - 24 V user power reserve

After all possible options have been connected, the transformer
ensures the availability of a usable 24 VA or 1 A power reserve for
the control circuit on site. This power reserve can not be used in
case of additionnal electric heaters control.
TM Control IOM and the certified wiring