8
• All plastic to metal threaded fittings should be avoided
due to the potential to leak. Use a flange fitted substitute.
• Teflon tape thread sealant is recommended to minimize
internal fouling of the heat exchanger.
• Use backup wrench. Do not overtighten connections.
• Route piping to avoid service access areas to unit.
• The piping system should be flushed prior to operation to
remove dirt and foreign materials from the system.
GROUND-LOOP APPLICATIONS — Temperatures be-
tween –3.9 and 43.3 C and a cooling capacity of 2.41 to
3.23 L/s per kW of flow per ton are recommended. In
addition to complying with any applicable codes, consider
the following for system piping:
• Piping materials should be limited to only polyethylene
fusion in the buried sections of the loop.
• 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. 11. 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 2 for
water quality guidelines.
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 9 — Install Field Power Supply Wiring

All field-installed wiring, including the electrical ground,
MUST comply with the National Electrical Code (NEC,
U.S.A.) as well as applicable local codes. In addition, all field
wiring must conform to the Class II temperature limitations de-
scribed in the NEC.
Refer to unit wiring diagrams Fig. 12-16 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 3A and 3B.
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 power block terminal. See Fig. 17. See Tables
3A and 3B for correct wire and maximum overcurrent pro-
tection sizing. See Table 4 for low voltage VA ratings.
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 420-3-50.
AB = 425 volts
BC = 422 volts
AC = 417 volts
Determine maximum deviation from average voltage:
(AB) 425 – 421 = 4 v
(BC) 422 – 421 = 1 v
(AC) 421 – 418 = 3 v
Maximum deviation is 4 v.
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.
RIB CRIMPED
LENGTH
(2 FT [0.6M] LENGTH STANDARD)
SWIVEL
BRASS
FITTING
BRASS
FITTING
EPT
Fig. 10 — Supply/Return Hose Kit
WARNING
Electrical shock can cause personal injury and death. Shut
off all power to this equipment during installation. There
may be more than one disconnect switch. Tag all discon-
nect locations to alert others not to restore power until work
is completed.
CAUTION
Use only copper conductors for field-installed electrical
wiring. Unit terminals are not designed to accept other
types of conductors.
= 100 x max voltage deviation from average voltage
average voltage
Average Voltage = 425 + 422 + 417
3
=1264
3
= 421