Ground-Water Applications; Step 8 - Field Power Supply Wiring; Power Connection; Supply Voltage - Carrier AQUAZONE 50HQL072-120 Installation, Start-Up And Service Instructions Manual

• Galvanized or steel fittings should not be used at any
time due to corrosion.
• All plastic to metal threaded fittings should be avoided
due to the potential to leak. Use a flange fitted substitute.
• Do not overtighten connections.
• Route piping to avoid service access areas to unit.
• Pressure-temperature (P/T) plugs should be used to mea-
sure flow of pressure drop.
GROUND-WATER APPLICATIONS — Typical ground-
water piping is shown in Fig. 7. In addition to complying
with any applicable codes, consider the following for sys-
tem piping:
• Install shut-off valves for servicing.
• Install pressure-temperature plugs to measure flow and
temperature.
• Boiler drains and other valves should be connected using
a "T" connector to allow acid flushing for the heat
exchanger.
• Do not overtighten connections.
• Route piping to avoid service access areas to unit.
• Use PVC SCH80 or copper piping material.
NOTE: PVC SCH40 should not be used due to system high
pressure and temperature extremes.
Water Supply and Quantity — Check water supply. Water
supply should be plentiful and of good quality. See Table 3 for
water quality guidelines.
IMPORTANT: Failure to comply with the above required
water quality and quantity limitations and the closed-
system application design requirements may cause damage
to the tube-in-tube heat exchanger that is not the responsi-
bility of the manufacturer.
In all applications, the quality of the water circulated
through the heat exchanger must fall within the ranges listed in
the Water Quality Guidelines table. Consult a local water treat-
ment firm, independent testing facility, or local water authority
for specific recommendations to maintain water quality within
the published limits.
Step 8 — Field Power Supply Wiring
To avoid possible injury or death due to electrical shock,
open the power supply disconnect switch and secure it in
an open position during installation.
Use only copper conductors for field-installed electrical
wiring. Unit terminals are not designed to accept other
types of conductors.
All field-installed wiring, including the electrical ground,
MUST comply with the National Electrical Code (NEC) as
well as applicable local codes. In addition, all field wiring must
conform to the Class II temperature limitations described in the
NEC.
Refer to unit wiring diagrams Fig. 8A-11B for fuse sizes
and a schematic of the field connections which must be made
by the installing (or electrical) contractor.
Consult the unit wiring diagram located on the inside of the
compressor access panel to ensure proper electrical hookup.
The installing (or electrical) contractor must make the field
connections when using field-supplied disconnect.
Operating voltage must be the same voltage and phase as
shown in Electrical Data shown in Tables 4 and 5.
Make all final electrical connections with a length of flexi-
ble conduit to minimize vibration and sound transmission to
the building.
POWER CONNECTION — Line voltage connection is
made by connecting the incoming line voltage wires to the
L side of the CC terminal. See Tables 4 and 5 for correct
wire and maximum overcurrent protection sizing.
SUPPLY VOLTAGE — Operating voltage to unit must be
within voltage range indicated on unit nameplate.
On 3-phase units, voltages under load between phases must
be balanced within 2%. Use the following formula to deter-
mine the percentage voltage imbalance:
% Voltage Imbalance
max voltage deviation from average voltage
= 100 x
Example: Supply voltage is 460-3-60.
AB = 452 volts
BC = 464 volts
AC = 455 volts
Average Voltage =
Determine maximum deviation from average voltage:
(AB) 457 – 452 = 5 v
(BC) 464 – 457 = 7 v
(AC) 457 – 455 = 2 v
Maximum deviation is 7 v.
Determine percent voltage imbalance.
% Voltage Imbalance = 100 x
= 1.53%
This amount of phase imbalance is satisfactory as it is
below the maximum allowable 2%.
Operation on improper line voltage or excessive phase
imbalance constitutes abuse and may cause damage to electri-
cal components.
NOTE: If more than 2% voltage imbalance is present, contact
local electric utility.
EXTERNAL LOOP POWER CONNECTION — If the unit
is to be connected to an external loop pump or flow controller,
connect the pump to the loop pump terminal block PB1. The
maximum power handling is 4 amps at 240 volts. The pumps
will automatically cycle as required by the unit.
208-VOLT OPERATION — All 208-240 volt units are factory
wired for 208 volts. The transformers may be switched to
240-volt operation (as illustrated on the wiring diagram) by
switching the red (208 volt) wire with the orange (240 volt)
wire at the L2 terminal.
12
average voltage
452 + 464 + 455
3
1371
=
3
= 457
7
457