9
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.
GROUND-LOOP APPLICATIONS — Temperatures between
–4 to 43 C and a liquid flow rate of 0.040 to 0.054 l/s per kW of
cooling capacity 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 any time due to
corrosion.
• Avoid all plastic to metal threaded fittings due to the
potential to leak. 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 of
pressure drop.
Step 8 — Electrical Wiring
All field installed wiring, including the electrical ground,
MUST comply with applicable local, national and regional
codes.
Refer to unit wiring diagrams Fig. 9-12 for a schematic of
the field connections, which must be made by the installing (or
electrical) contractor. Refer to Electrical Data 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 Table 3.
Make all final electrical connections with a length of flexi-
ble conduit to minimize vibration and sound transmission to
the building.
Table 2 — Water Quality Guidelines
*If the concentration of these corrosives exceeds the maximum allowable level, then the potential for serious cor-
rosion problems exists.
†Sulfides in the water quickly oxidize when exposed to air, requiring that no agitation occur as the sample is
taken. Unless tested immediately at the site, the sample will require stabilization with a few drops of one Molar
zinc acetate solution, allowing accurate sulfide determination up to 24 hours after sampling. A low pH and high
alkalinity cause system problems, even when both values are within ranges shown. The term pH refers to the
acidity, basicity, or neutrality of the water supply. Below 7.0, the water is considered to be acidic. Above 7.0,
water is considered to be basic. Neutral water contains a pH of 7.0.
NOTE: Hardness in mg/l is equivalent to ppm.
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.
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.
CONDITION
ACCEPTABLE LEVEL
pH
7 to 9 range for copper. Cupronickel may be used in the 5 to 9 range.
Total
Hardness
Calcium and magnesium carbonate should not exceed 350 ppm.
Iron Oxides
Less than 1 ppm.
Iron Bacteria
No level allowable.
Corrosion*
Max Allowable Level
Coaxial Metal
Ammonia, Ammonium Hydroxide
0.5 ppm
Cu
Ammonium Chloride, Ammonium Nitrate
0.5 ppm
Cu
Ammonium Sulfate
0.5 ppm
Cu
Chlorine/Chlorides
0.5 ppm
CuNi
Hydrogen Sulfide†
None Allowable
—
Brackish
Use Cupronickel heat exchanger when concentrations of calcium or sodium chloride are
greater than 125 ppm are present. (Seawater is approximately 25,000 ppm.)
