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10 | Installation
Step 7-Pipe Connections
Depending on the application there are 3 types of WSHP
piping systems to choose from: water loop, ground
water-and ground loop.
All WSHP units use female pipe thread fittings for water
connections. When making piping connections
considered the following:
•
Insulation may be required on piping to avoid
condensation in the case where fluid in loop piping
operates at temperatures below dew point of
surrounding air.
•
Piping systems that contains steel pipes or fittings
may be subject to galvanic corrosion. Dielectric
fittings may be used to isolate the steel parts of the
system to avoid galvanic corrosion.
Water Loop applications
Water loop applications usually include a number of
units plumbed to a common piping system. Maintenance
of any of the units can introduce air into the system.
Therefore, air elimination equipment comprises a major
portion of the mechanical room plumbing.
The flow rate is usually set between 2.25 and 3 GPM per
ton of cooling capacity. For proper maintenance and
servicing, pressure-temperature (P/T) ports are
necessary for temperature and flow verification.
In addition to complying with any applicable codes,
consider the following for system piping:
•
Piping systems using water temperatures below
o
50
F require 1/2 inch closed cell insulation on all
piping surfaces to prevent pipe sweating.
•
Avoid all plastic to metal threaded fittings due to the
potential for leaks.
•
Teflon tape thread sealant is recommended to seal
pipe threads.
•
Use Backup wrench. Do not overtighten
connections.
•
Route piping to avoid service access areas to unit.
•
Flush the piping system prior to operation to remove
dirt and foreign materials from the system.
Ground Loop Applications
Temperatures between 20
capacity of 2.25 to 3 GPM of flow per ton is
recommended. In addition to complying with any
applicable codes, consider the following for system
piping:
•
Limit piping materials to only polyethylene fusion in
the buried sections of the loop.
•
Do not use galvanized or steel fittings at anytime
due to corrosion.
•
Avoid all plastic to metal threaded fittings due to the
potential for leaks. Use a flange fitted substitute.
•
Do not overtighten connections.
•
Route piping to avoid service access areas to unit.
•
Use pressure-temperature (P/T) plugs to measure
flow and pressure drop.
8 733 944 336 (2016/09)
º
º
and 110
F and a cooling
Subject to change without prior notice
Step 8 Wire Field Power Supply
High Voltage
All field-installed wiring must comply with the National
Electric Code as well as all applicable local codes. Refer
to the unit electrical data on the unit nameplate for wire
and branch circuit protection sizing. Supply power
voltage and phasing should match the required voltage
and phasing shown on the unit nameplate. Operating the
unit below the minimum voltage, above the maximum
voltage or with incorrect phasing can result in poor
system performance or damage to the heat pump. All
field wiring should be installed by qualified and trained
personnel. Refer to the unit wiring diagram for field
connection requirements.
Power wiring to the heat pump should be enclosed in
flexible conduit to minimize the transmission of
vibration from the unit cabinet to the building.
For heat pumps with unit mounted disconnect switches,
field power should be connected to the marked
terminals on the disconnect switch. For heat pumps
without unit-mounted disconnect switches (except for
460-volt units noted below and units with dual power
supply), power is connected to the line (L) side of the
compressor contactor and the ground lug in the unit
electrical box.
Units with Dual Power Supplies
For models with dual power supplies, one power supply
feeds the compressor and a second power supply feeds
the unit fan motor and control circuit. The compressor
power supply should be connected to the line (L) side of
the compressor contactor. The fan motor and control
circuit power supply meets the voltage, amperage and
phase requirements of its load. Refer to the unit name
plates for requirements.
460-V Models with Constant Airflow Motors
The 460-V heat pumps with the constant airflow motor
option require a properly sized neutral wire with the
power supply wiring in addition to the three high voltage
wires and the ground wire. These units employ a 265-V
motor that requires power from one phase of the 460-V
supply and the neutral wire.
CAUTION: The unit ground wire should
never be used as a neutral wire
Transformer Settings for 208/230-V Units
As a factory built, all 208/230-V operation unless the
wire for 208-v option is ordered. For Job sites with a
208-V power supply, the primary leads on the unit
transformer will need to be changed from 240-V to 208-
V. Refer to the unit wiring diagram for details.
NOTICE: All High voltage connections must
be torqued as specified on contactor
specifications to avoid the risk of
overheating
LV Heat Pump Series
LV Heat Pump Series
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