Carrier 50PSH Heat Pump User Manual


 
13
Optional pressure-rated hose assemblies designed specifi-
cally for use with Carrier units are available. Similar hoses can
be obtained from alternate suppliers. Supply and return hoses
are fitted with swivel-joint fittings at one end to prevent kink-
ing during installation.
Refer to Fig. 14 for an illustration of a supply/return hose
kit. Male adapters secure hose assemblies to the unit and risers.
Install hose assemblies properly and check them regularly to
avoid system failure and reduced service life.
Step 8 — Wire Field Power Supply
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. 15-25 for a schematic of
the field connections, which must be made by the installing (or
electrical) contractor. Refer to Tables 4-6 for fuse sizes.
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 4-6.
Make all final electrical connections with a length of flexi-
ble conduit to minimize vibration and sound transmission to
the building.
POWER CONNECTION — Make line voltage connection
by connecting the incoming line voltage wires to the line
side of the compressor contactor terminal as shown in
Fig. 26. See Tables 4-6 for amperage ratings to provide cor-
rect 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
Example: Supply voltage is 460-3-60.
AB = 452 volts
BC = 464 volts
AC = 455 volts
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.
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
your local electric utility.
208-VOLT OPERATION — All 208-230 volt units are factory
wired for 208 volts. The transformers may be switched to
230-volt operation by switching the red (208 volt) wire with
the orange (230 volt) wire at the L1 terminal.
460-VOLT OPERATION Units using 460-v and an
ECM (electronically commutated motor) fan motor, modulat-
ing HWR, and/or internal secondary pump will require a
neutral wire from the supply side in order to feed accessory
with 265-v.
CAUTION
Backup wrench is required when tightening water connec-
tions to prevent water line damage. Failure to use a backup
wrench could result in equipment damage.
WARNING
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.
CAUTION
Use only copper conductors for field-installed electrical
wiring. Unit terminals are not designed to accept other
types of conductors. Failure to use copper conductors could
result in equipment damage.
= 100 x
max voltage deviation from average voltage
average voltage
Average Voltage =
452 + 464 + 455
3
=
1371
3
= 457
% Voltage Imbalance = 100 x
7
457
= 1.53%
Rib Crimped
Length
(2 ft Length Standard)
Swivel
Brass
Fitting
Brass
Fitting
MPT
Fig. 14 — Supply/Return Hose Kit
A50-7734