External Pump Hwg Power Connection; Step 7 - Low Voltage Wiring - Carrier Aquazone 50RWS036-360 Installation, Start-Up And Service Instructions Manual

Water-to-water water source heat pump units
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Contactor -CC
L3
Unit Power Supply
See electrical table for
wire and breaker size
CB
Transformer
Fig. 6G — Typical Field Wiring —
50RWS036-060 Units (Without HWG)
Fig. 6H — Typical Field Wiring
50RWS036-060 Units (With HWG)
L1
L2 L3
Grnd
Power Distribution
Block
Transformer
Contactor -CC1
Contactor -CC2
NOTE: Use only L1 and L2 for 208/230-1-60 voltage.
Fig. 6I — Typical Field Wiring —
50RWS120,360 Units
Capacitor
Grnd
L2
L1
C Control
Low Voltage
Connector
C Control #1
C Control #2
SUPPLY VOLTAGE — Operating voltage to unit must be
within voltage range indicated on unit nameplate.
On 3-phase units, voltages between phases must be bal-
anced within 2%. Use the following formula to determine 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.
EXTERNAL PUMP HWG POWER CONNECTION —
After all HWG piping is connected and water lines are filled,
the pump power wires should be connected to the terminals on
the HWG power block PB2 (terminals T1 and T2). See
Fig. 6H.
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.
Step 7 — Low Voltage Wiring
THERMOSTAT CONNECTIONS — The thermostat should
be wired directly to the Aquazone™ control board. See
Fig. 6A-6E.
WATER FREEZE PROTECTION — The Aquazone control
allows the field selection of source fluid freeze protection
points through jumpers. The factory setting of jumper JW3
(FP1) is set for water at 30 F. In earth loop applications, jumper
JW3 should be clipped to change the setting to 10 F when
using antifreeze in colder earth loop applications. See Fig. 7.
18
average voltage
452 + 464 + 455
3
1371
=
3
= 457
7
457

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